Deposition of Coating to Protect Waste Water Reservoir in Acidic …downloads.hindawi.com/journals/amse/2018/4050175.pdf · 2018. 1. 30. · spraying in the arc thermal spraying process

Research ArticleDeposition of Coating to Protect Waste Water Reservoir in AcidicSolution by Arc Thermal Spray Process

Han-Seung Lee1 Jin-ho Park1 Jitendra Kumar Singh 1 and Mohamed A Ismail2

1Department of Architectural Engineering Hanyang University 1271 Sa 3-dong Sangrok-gu Ansan 15588 Republic of Korea2Department of Civil and Construction Engineering Faculty of Engineering and Science Curtin University Malaysia CDT 25098009 Miri Sarawak Malaysia

Correspondence should be addressed to Jitendra Kumar Singh jk200386hanyangackr

Received 30 January 2018 Accepted 29 March 2018 Published 23 April 2018

Academic Editor Jan Cizek

Copyright copy 2018Han-Seung Lee et alis is an open access article distributed under the Creative CommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

e corrosion characteristics of 304 stainless steel (SS) and titanium (Ti) coatings deposited by the arc thermal spray process in pH4 solution were assessede Ti-sprayed coating exhibits uniform less porous and adherent coating morphology compared to theSS-sprayed coating e electrochemical study that is electrochemical impedance spectroscopy (EIS) revealed that as exposureperiods to solution were increased the polarization resistance (Rp) decreased and the charge transfer resistance (Rct) increasedowing to corrosion of the metallic surface and simultaneously at the same time the deposition of oxide filmscorrosion on theSS-sprayed surface while Ti coating transformed unstable oxides into the stable phase Potentiodynamic studies confirmed thatboth sprayed coatings exhibited passive tendency attributed due to the deposition of corrosion products on SS samples whereasthe Ti-sprayed sample formed passive oxide films e Ti coating reduced the corrosion rate by more than six times compared tothe SS coating after 312 h of exposure to sulfuric acid- (H2SO4-) contaminated water solution that is pH 4 Scanning electronmicroscope (SEM) results confirmed the uniform and globular morphology of the passive film on the Ti coating resulting inreduced corrosion On the other hand the corrosion products formed on SS-sprayed coating exhibit micropores with a net-likemicrostructure X-ray diffraction (XRD) revealed the presence of the composite oxide film on Ti-sprayed samples and lep-idocrocite (c-FeOOH) on the SS-coated surfacee transformation of TiO and Ti3O into TiO2 (rutile and anatase) and Ti3O5 after312 h of exposure to H2SO4 acid reveals the improved corrosion resistance properties of Ti-sprayed coating

1 Introduction

Concrete is a material that can withstand and sustain ex-posure to an aggressive environment over long periods andresist deterioration erefore concrete is a reliable anddurable construction material with versatile applications inwaste water reservoirs buildings bridges towers roads andso on However it is also a porous material which meansthat aggressive ions such as Clminus CO3

minus and SO4minus can slowly

or steadily penetrate and move toward the embedded steelrebar thus causing corrosion that leads to premature concretefailure [1ndash3]

e major factor in concrete deterioration is acidicimpurities in its surrounding [4] Different external coatingshave been applied to protect concrete and the embeddedsteel rebar Swamy and Tanikawa used acrylic rubber as an

external coating material for concrete in accelerated wet-dryand saline environments [5] ey found that this coatingwithstood saline and ozone exposures but suffered extensivecracking when exposed to ultraviolet radiation ereforepolymeric coating is not suitable for concrete coating be-cause of vast differences in the thermal contraction andexpansion coefficients between the concrete and polymer

e presence of sulfur-reducing bacteria in waste watermakes it acidic [6 7] e minimum pH that is 45 of wastewater can be obtained [8] depending on the source andenvironment where it is produced

e acidity of waste water influences the deterioration ofthe concrete and steel rebar erefore to protect these fromcorrosion SS grouting and anchoring have been widely used[6 7] SS plates are used in waste water reservoirs to protectthe concrete and embedded steel rebar But cost factors are

HindawiAdvances in Materials Science and EngineeringVolume 2018 Article ID 4050175 13 pageshttpsdoiorg10115520184050175

affecting the use of such steel plates on the outer surface ofconcrete Nonetheless SS plates and other protective methodsor surface treatments are frequently used to protect the con-crete and waste water reservoirs owing to their high resistanceto corrosion [9] Also the nanostructured and PVD coatingswere used in high-speed drilling and cutting instruments toenhance the mechanical properties of tools [10 11]

Amethod to deposit coatings onto the concrete surface isan important factor in the deposition of high melting pointcorrosion-resistant metals One view is that the coatingprocess should be considered for deposition on account of itsfeasibility and applicability High corrosion-resistant ma-terials such as SS nickel (Ni) tungsten (W) molybdenum(Mo) chromium (Cr) and Ti need a specific depositionprocess e arc thermal spray process is suitable and fea-sible for depositing these metals onto any substrate [12ndash17]

e arc thermal spray process is an easy process for thedeposition of coatings onto concrete and steel substratesis process involves arc spraying with twin metal wires onoppositely charged tips that use atomized hot air to depositthe coating onto the substrate [12] During the coatingprocess melted metal droplets are deposited and form athick layer on the substrate During coating depositionporesdefects are formed which is an inherent property ofthe arc thermal spray process [13ndash15] Pore formationdepends on the metal to be used and spraying parameters ofthe process

Our recently published paper showed that the 316L SScoating applied on the concrete substrate and then sealedwith alkyl epoxide effectively protected the surface fromcorrosion in pH 4 5 and 6 solutions e most destructivewas the pH 4 solution because of its higher acidity comparedwith the other solutions [16] In the pH 5 solution the testedcoatings exhibited the highest corrosion resistance becauseof the presence of undissociated water molecules thatformed a protective passive film on the coating surface isexperiment was carried out for instantaneous exposurethere is currently no study on prolonged exposure

e pH 4 solution is an aggressive environment and thesurface is expected to deteriorate dramatically is pHsolution increases the risk of corrosion due to its more acidicnature If a coating can withstand this pH then it can extendthe protection of a waste water reservoir against corrosion

e present investigation aims to protect the concrete ofa waste water reservoir from deterioration spalling andthawing during prolonged exposure to an acidic environ-ment using surface treatment with 304 SS and Ti metalliccoatings by an arc thermal spray process is communi-cation is an advancement of our earlier published work [16]e acidic condition was simulated by mixing 01MmiddotH2SO4(pH 1) in distilled water to reduce the pH of distilled waterfrom 65 to 40 at 25degC Assessments of the corrosion re-sistance of these coatings were carried out using differentelectrochemical techniques

2 Experimental Section

21 Process of Coating e 304 SS and Ti coatings wereapplied to grit-blastedmild steel containing carbon (C) 024

silicon (Si) 026 manganese (Mn) 095 phosphorus (P)

0016 sulfur (S) 0008 copper (Cu) 002 chromium(Cr) 004 nickel (Ni) 003 and iron (Fe) balance (wt)and to concrete substrates by an arc thermal spray processe coating deposited onto the steel substrate was used tostudy its electrochemical and physical characteristics asshown in Figure 1 while the coating deposited onto theconcrete surface was used for bond adhesion measurement

Concrete is a low-conducting material that cannot beused for electrochemical studies Hence it was not con-sidered for electrochemical studies A 16mm diameter wireof 304 SS and commercially pure Ti was used for metalspraying in the arc thermal spraying process to deposit thecoatings onto the substrates

Prior to the deposition of coatings the steel substrate waspickled with 10 vv HCl thoroughly washed with distilledwater dried and finally grit-blasted with 07 and 08mmsteel balls using a pressure machine at 07MPa Coatingthickness was measured using a nondestructive Elcometer456 dry film thickness gauge at different locations on the steeland concrete substrate the thickness was approximately200 microm (plusmn5 microm)

e coatings were applied to the substrate by the arcthermal spray gun (LDU3 electric arc wire spray gunOerlikonMetcoTM Switzerland) process using 304 SS and Tiwires with a circular slit of hot and compressed air [17ndash20]e melted metal particles diffused onto the substrate andcooled at room temperature resulting in the formation ofporesdefects on the coating

e spraying of metallic coating on the target substratewas carried out by keeping the sample 20 cm away from thespray gun at an air pressure of 6 bar e spraying voltageand current were maintained at approximately 30V and200mA respectively [15 21ndash23]

After applying the coating on the concrete substratecoating adhesion was measured according to the KS F4716test method [24] In this process a 300mmtimes 300mm sec-tion of the coated substrate was taken for the adhesion test(Figure 1)

22 Electrochemical Experiments Electrochemical experi-ments were carried out on the deposited coatings and 304 SSplate For the sake of comparison with deposited coating wehave chosen to characterize the 304 SS plate

To perform the electrochemical experiments a solutionwas prepared in double distilled water by adding a few dropsof 01MmiddotH2SO4 to reduce the pH to 4 at 25degC ese

2 mm 300 mm

200 microm

300 mmSteel

Coating

Figure 1 Sketch of coating applied on the steel substrate

2 Advances in Materials Science and Engineering

experiments were performed using three electrode systems[17] where the coating acted as the working electrode (WE)the platinum wire acted as the counterelectrode and thesilversilver chloride (AgAgCl) acted as the reference elec-trode e area of the WE was 078 cm2 and was fixed for allthe samples

EIS experiments were carried out by changing the fre-quency of a 10mV sinusoidal voltage from 100 kHz to001Hz e potentiodynamic experiments were performedfrom minus04V to +08V versus AgAgCl at 1mVs scanrate e potentiostat used in this study was a VersaSTAT(Princeton Applied Research Oak Ridge TN USA) anddata analysis was carried out using the Metrohm AutolabNova 110 software

e 304 SS plate was abraded with an emery paper from60 microm up to 300 microm to remove the native oxides from thesurface prior to starting electrochemical experiments Allelectrochemical experiments were conducted in triplicate atroom temperature (27plusmn 1degC) to generate reproducible data

23 Characterization of Coating e morphology of thedeposited coatings and 304 SS plate was determined by anSEM (Philips XL 30) operated at 15 kV Prior to taking theimages of the samples these were coated with platinum toincrease their conductivity and avoid a charging effect

XRD (Philips XrsquoPert-MPD) studies of the coatings and304 SS plate were performed using Cu-Kα radiation(λ154059 A) generated at 40 kV and 100mA e scan-ning rate to scan XRD data from 10 to 90deg was at 05degmin

3 Results and Discussion

31 Adhesion Test of Sprayed Coatings Adhesion measure-ments were carried out after deposition of coatings onto theconcrete surface by arc thermal spraying is was measuredfor four samples and the average was calculatede averageadhesion values of 304 SS- and Ti-sprayed surfaces were 339and 272MPa respectively e SS-sprayed coating exhibitshigher adhesion values than Ti-sprayed coating e stan-dard deviation of SS- and Ti-sprayed coating was calculatedand these were 040 and 024MPa respectively is indicatesthat SS coating adhered strongly to the concrete surfacewhereas Ti-sprayed coating adhered 125 times lesser than the304 SS coating e higher adhesion values of the SS coatingmay be attributed to small interfacial separation between theconcrete substrate and metallic particles while that for Ti waslarge [25]

32 Morphology of SS Plate and Sprayed Coating emorphologies of the 304 SS plate and deposited coatingson the mild steel substrate were characterized by SEMFigure 2 shows the SEM images of the deposited coatingsand 304 SS plate e SS plate surface exhibited a smoothand very finely scratched line (Figure 2(a)) while the de-posited coatings had many cracks and defects over thesurfaces (Figures 2(b) and (c))

e scratched line on the plate surface was caused byabrasion with an emery paper up to 300 microm because thisgrade of the emery paper is hard and makes some fine

(a)

Pores

Valley

(b)

Cracks

(c)

Figure 2 FE-SEM images of the (a) SS plate (b) SS-sprayed surface and (c) Ti-sprayed surface

Advances in Materials Science and Engineering 3

defectslines on the surface e SS-sprayed surface showedcoagulated valleys and uneven deposition while the Ti-sprayed surface showed uniform nanosized globular andne elongated cracks e ne cracks on the Ti-sprayedsurface might be due to formation of thin and nanoscaledbrittle oxides e morphology of SS-sprayed coating can beattributed due to the sudden cooling of melted metal par-ticles at room temperature (27plusmn 1degC)

emicrostructure of the SS-sprayed coating (Figure 2(b))could allow the deposition of aggressive ions water andmoisture particles on valleys which cause localized orcrevice corrosion e Ti-sprayed coating also exhibitedne cracking on the surface but had little inuence on thedeposition of water molecules Owing to the smooth mi-crostructure of the Ti coating water molecules may slide othe surface

33 Phase Identication of SS Plate and Sprayed Coatings byXRD XRD was performed to determine the phases presentin the coatings and plate surfaces e results are plottedbetween 2θ10deg and 90deg versus intensity in counts persecond (CPS) and shown in Figure 3 e SS plate andsprayed surfaces exhibited the austenite phase of the Fe-Cr-Ni alloy that is 304 SS [26 27] Besides this phase in the SS-sprayed surface magnetite (Fe3O4) is also observed and itis due to the partial oxidation of coating during the sprayingprocess

XRD of Ti-sprayed coating showed Ti [28] and twooxides such as TiO and Ti3O which were formed due tohigher melting point of it than SS where there are possi-bilities to oxidize the deposited coating e another reasonto oxidize the Ti is high anity of it with atmosphericoxygen and thus to form surface oxide lms such as TiO orTi3O e formation of these two oxides of Ti in open at-mosphere has also been reported by other researchers[29 30] However these oxides are amorphous brittle andunstable in in vivo conditions which easily can be removedsimply by brushing with soft tissues [31ndash33]

34 Electrochemical Studies of SS Plate and SprayedCoating inpH 4 Solution

341 EIS Studies e samples were immersed in pH 4solution for dierent periods of exposure EIS was carried outto study their corrosion characteristics ese results areshown in Figures 4 and 5 e electrical equivalent circuit(EEC) is shown in the corresponding Nyquist plots e EECof the SS plate exposed to the pH 4 solution for 1 h is shown inFigure 4(a) In theNyquist plot of the SS plate the sample after1 h of exposure is dierentiated by two depressed semicircleloops such as one at high while another at the lower studiedfrequency For more clarity of plots at high frequency theNyquist result of samples is shown in Figure S1 (supple-mentary gure) ese results can be explained either by theheterogeneity of the solid surface or by the dispersion of somephysical properties e interface of the surface cannot beconsidered as an ideal capacitor due to heterogeneity of thesurface and it may involve a constant-phase element (CPE) asa substitute of the ideal capacitor e rst EEC consists ofthe solution resistance (Rs) polarization resistance (Rp) andCPE1 due to the metal surface and nonideal double-layercapacitance behaviour [34ndash36] e Rp and CPE1 are parallelto each other However the second EEC contains the chargetransfer resistance (Rct) and CPE2 e formation of Rct maybe due to formation of the protective passive layer on the SSplate surface in acidic pH solution after 1 h of exposureesetwo EECs are connected in series to each other

e EECs for the SS- and Ti-sprayed coating systems aresomewhat dierent from the SS plate and they are insertedin Figure 4(a) e dierent EECs for these coatings may beattributed to the inherent property of the arc thermal sprayprocess where coatings suer from surface defects Due toreaction on the metal surface Rct participated owing toinitiation of the corrosion process in acidic pH solution ereaction on the metal surface caused by Rct led to the for-mation of a passiveoxide layer on the metal surface whichincreased the resistance and reduced the corrosion reactione CPE1 due to a nonideal behaviour of the coating surfaceand Rp are parallel to each other while another EEC isconnected in series to Rp which contains CPE2 and Rct [15]e CPE2 and Rct are parallel to each other

e Nyquist plots reveal the real characteristics of thesamples after 1 h of exposure (Figure 4(a))e samples wereexposed to the solution for 1 h to stabilize the potentialthereafter EIS measurements were performed

Figure 4(a) shows the two semicircle loops in the Nyquistplots exhibited by coated samples e SS- and Ti-sprayedcoatings show zigzag and scattered plots which might be dueto low conductivity of electrolytes deposition of defectivecoating formation of a defective passive lm and thepresence of more resistive elements such as Ti in Ti-sprayedcoating while Cr and Ni in SS-sprayed samples [37ndash40]ese results are attributed to the fact that both sprayedsamples exhibit capacitive properties due to the presence ofdefects However the Ti coating imposed a resistance greaterthan the SS coating due to the formation of a passiveoxidelm with capacitive behaviour which enabled surface re-sistance to penetrate the ions of the acidic solution

10 20 30 40 50 60 70 80 90Au

steni

te

Auste

nite

Auste

nite

SS plate

SS sprayed

Ti sprayed

2θ (degree)

TiO

Ti3O

Fe3O

4

Fe3O

4

Fe3O

4

Fe3O

4

Ti3O

Ti3O

Ti3O

TiO

Ti Ti Ti Ti

Inte

nsity

(CPS

)

Figure 3 XRD of the SS plate and sprayed coatings by the arcthermal spray process (05degmin)

4 Advances in Materials Science and Engineering

In the sulfuric acid solution the Ti surface tends to formdefective passive lms with high resistance Similar resultshave been observed by Baron et al on TiAlV and TiAlNballoys in Tyrodersquos solution [41]

e dimensions of the semicircle loop of SS plate samplesclearly show high capacitive property that enables the sur-face to resist the penetration of the solution e capacitiveproperty of the passive lm on the SS plate was attributed tothe formation of Cr-enriched oxide and NiO in the H2SO4-contaminated water solution [42]

e dimensions of the semicircle loops of SS- and Ti-sprayed coatings were less than those of the SS plate becausethe sprayed samples were more susceptible to corrosion

owing to the formation of defectspores on the coatingsurface in the solution after 1 h of exposure

e impedance at low frequency (001Hz) and the phaseθ (deg) of Bode plots were plotted against log |Z| (Ωmiddotcm2) versuslog f (Hz) and θ (deg) versus log f (Hz) in Figure 4(b) respec-tively e impedance values of the SS plate sample weregreater than those of the SS and Ti coatings e SS coatingexhibited lower impedance values because of the presence ofmore defectspores at locations where the chances of pene-tration by the acidic solution are high and this initiated thedeterioration of the coating

From the log |Z| (Ωmiddotcm2)-log f (Hz) Bode plots (Figure 4(b))it can be seen that at high frequency (100 kHz) resistance was

Rp

CPE1

CPE2Rs

01 Hz

RctRp

RsCPE1 CPE2

Rct

0 50000 100000 150000 200000 250000

0

50000

100000

150000

200000

250000

SS plateSS sprayedTi sprayed

01 Hz01 Hz

Zreal (Ωcm2)prime

minusZ i

mag

inar

y (Ωcm

2 )Prime

(a)

10000

100000

log

|Z| (

Ωcm

2 )

01 1 10 100 1000 10000 100000001log f (Hz)

SS plateSS sprayedTi sprayed

8070605040302010

ndashθ

(deg)

0ndash10ndash20

(θ)|Z|

(b)

Figure 4 Impedance spectra (a) Nyquist and (b) Bode |Z| and (θ) of the SS plate and sprayed coatings in pH 4 solution after 1 h of exposure(100 kHz to 001Hz)

Rs

Rp

Rct

CPE2

CPE1

CPE1

CPE2Rs

RpRct

01 Hz

01 Hz01 Hz

W

0

50000

100000

150000

200000

250000

50000 100000 150000 200000 2500000

SS plateSS sprayedTi sprayed

W

minusZim

agin

ary (

Ωcm

2 )Prime

Zreal (Ωcm2)prime

(a)

(θ)|Z|

10000

100000

log

|Z| (

Ωmiddotcm

2 )

01 1 10 100 1000 10000 100000001log f (Hz)

80706050403020100ndash10ndash20

SS plateSS sprayedTi sprayed

ndashθ

(deg)

(b)

Figure 5 Impedance spectra (a) Nyquist and (b) Bode |Z| and (θ) of the SS plate and sprayed coatings in pH 4 solution after 312 h ofexposure (100 kHz to 001Hz)

Advances in Materials Science and Engineering 5

moreover identical to that observed at low frequency that is001Hz which might be attributed to the low conductivity ofacidic pH solution

In this study the solution was prepared by adding a fewdrops of 01MmiddotH2SO4 to distilled water e solution con-ductivity was very low which caused the resistance in totalimpedance e conductivity of the solution is an importantparameter that must be considered in electrochemicalstudies However the Ti coating exhibited higher impedancethan the SS coating due to formation of a thick and pro-tective passive oxide film e low impedance values of thesprayed samples are due to the presence of more defects orless interfacial resistance between the splats of coating thanon the SS plate sample

e surface finish and coating microstructure play animportant role to determine the corrosion resistance prop-erties of materials in the solution e pH 4 solution is veryaggressive and causes localized or pitting corrosion of theoxide films formed during exposure [43ndash45]

e defective parts of coatings can function as an anodewhile the remaining acts as a cathode resulting in the for-mation of microgalvanic cells on the surface e presence ofmicrogalvanic cells enhances the corrosion rate of materialsthus there is a chance of getting low impedance Such ob-servations are found in SS- and Ti-sprayed coatings In view ofthe above it can be observed that the SS coating exhibitedvalley-type deposits (Figure 2(b)) where the acidic solutioncould stagnantdeposit and cause localized and crevice cor-rosion During the initial period of exposure both sprayedcoatings had defects that resulted in lower impedance valuesthan the SS plate surface

e SS plate shows a minus40deg shift of the phase anglemaxima at the lower studied frequency and reveals highresistance to corrosion in the pH 4 solution (Figure 4(b))On the other hand Ti and SS coatings exhibited minus1deg and minus2degshifts respectively which indicate their susceptibility tocorrosion during the initial period of exposure [37] In themiddle frequency range the samples exhibited scatteringwhich might be due to the capacitive response of the de-fective passive film that was formed during exposure of thesamples to H2SO4 solution [38ndash40]

e shifting of maxima at the higher studied frequency(100 kHz) is due to the deposition of corrosion products onthe SS-sprayed sample whereas on the Ti-coated sample it isdue to formation of the resistive passive film It can be seenthat the Ti coating exhibited approximately minus57deg shift fol-lowed by the SS coating at minus38deg while the SS plate had thelowest shift at minus23degese results indicate that the Ti-sprayedsurface formed a protective passive film owing to reaction atthe coatingsolution interface us the Ti coating exhibitedhigher resistance to the acidic solution

As the exposure periods were extended the increaseddimensions of semicircle loops in the Nyquist plots showedincreased corrosion resistance [46] e bigger loops in theNyquist plots reveal high resistance to corrosion in anyenvironment Such results can be seen from Figure 5(a) after312 h of exposure to pH 4 solution e EEC for the SS plateafter 312 h of exposure is inserted in Figure 5(a) eWarburg impedance (W) is caused by diffusion of the

protective passive layer on the SS plate surface in the H2SO4-contaminated solution Rct and W are parallel to theCPE2 [16]

At longer periods of exposure (312 h) many parametersare involved owing to the complex reaction process on themetalsolution interface

All samples exhibited two loops in the Nyquist plots oneat higher and another at lower frequenciese loops formedat higher and lower frequencies because of the solutionresistance and the reaction at the metalsolution interfacerespectively [47ndash51] As the exposure period is increasedstrengthening of the passive film on the SS plate may occur[52] However in case of Ti there is a possibility of for-mation of the protective passive film due to transformationof unstable titanium oxides into stable oxides while on SS-sprayed samples it is due to deposition of corrosion productson the coating defects in H2SO4-contaminated water solution[53] e two semicircle loops of Ti and SS coatings weresuccessfully distinguished from each other for this exposureperiod erefore the Ti coating had provided greaterprotection than the SS coating ese two diffused semicircleloops on sprayed coatings are not clearly seen because of thereduced conductivity of the solution and scattered data

e dimensions of semicircle loops in the Nyquist plot ofthe Ti coating were bigger indicating that the anodic surfacearea of the coating was decreased by the formation of theprotective oxide film rather than SS coatinge SS plate hadhigher resistance to the H2SO4-contaminated solution ow-ing to the formation of the protective passive film [42]

e SS plate surface exhibited the protective passive filmthat is resistant to corrosion because the values of both Zprimerealand minusZPrimeimaginary axes are increased (Figure 5(a)) From theinitial to the prolonged exposure the SS plate showed higherresistance to corrosion which can be attributed to the for-mation of compact and uniform passive layers [42]

On the other hand the SS and Ti coatings showed lessresistance to corrosion than the SS plate because of theformation of surface defectscracks which enhanced thecorrosion rate due to penetration of aggressive solution Itcan be seen from Figure 5(a) that the SS and Ti coatingsexhibit diffused semicircle loops separated by two small loops

e bigger loop shifted toward ZPrimeimaginary because of theformation of the capacitive passive filmcorrosion productse lower frequency loop shifted toward Zprimereal of the Nyquistplots (Figure 5(a)) because of the increased resistance tocorrosion

e nature of corrosion productspassive films plays amajor role in controlling the corrosion of the sprayed samplesat prolonged exposure [53] In case of the SS plate and Ticoating the passive film controls the corrosion of the samplesere is no role played by chemistry rather morphologycontrols the corrosion of samples

e impedance values measured at lowest frequency(001Hz) in Figure 5(b) were found to be the highest thanthose of 1 h of exposure to acidic pH solution for all samplese impedance values of both sprayed coatings exhibitedalmost identical characteristics but those of the Ti coatingswere higher is result is attributed to the fact that the Ticoating is more resistant to corrosion in the H2SO4 solution

6 Advances in Materials Science and Engineering

at pH 4 after 312 h of exposure [45 54ndash56] e Ti and SScoatings exhibited higher resistance at the highest studiedfrequency due to formation of passive films and depositionof corrosion products in defectspores respectively andshowed higher impedance

After 312 h of exposure the corrosion of SS and Ticoatings in acidic solution was controlled by their respectivecorrosion products and passive film [53] e impedancevalue of Ti coating was greater than that of the SS-sprayedcoating owing to the more stable and adherent passive oxidefilm formed on its surface after exposure to the solution eSS plate had the highest impedance values compared to thesprayed coatings

e phase shift θ (deg)-log f (Hz) Bode plots of samples after312 h of exposure to solution are shown in Figure 5(b) escattered data shown in the middle frequency range areattributed due to the defectiveporous oxide film caused bythe corrosion products of SS and Ti coatings

e shifting of the phase angle maxima toward minus75deg forthe SS plate was attributed to the formation of the homo-geneous passive film on the surface which revealed thestrengthening of the film in the solutionis result indicatesthat the passive filmcorrosion products formed on the plateare surface resisted to the attack of corrosive ions [57]

e impedance data were validated by KramersndashKronig(K-K) transformation by transforming the real axis into theimaginary axis and vice versa e K-K transformations areshown in Figure S2 and have been described elsewhere[58ndash60] ese results confirm the agreement between theexperimental data and K-K transformations which is ac-cordance with the linear system theory

Brugrsquos formula has been widely used to extract effectivecapacitance values from CPE parameters for studies ondouble layers [61] Brug et al [62] have established therelationship between CPE parameters and effective capaci-tance (Ceff) associated with the CPE which can therefore beexpressed as follows

Ceff Q1n

R(1minusn)n

(1)

where Q is the CPE parameter such as nonideal double-layercapacitance R is a resistance caused by dissolution of the

metal or alloy at the metalsolution interface in low fre-quency and n is the CPE exponent (minus1lt nlt 1) When n issim1 05 0 and minus1 the CPE is equivalent to a capacitor theWarburg diffusion a resistor and an inductor respectively

After fitting of EIS data to a suitable EEC the electro-chemical parameters are shown in Table 1 e Rs is veryhigh for all systems due to low conductively of the solutione Rs is gradually decreased with increasing exposureperiods due to involvement of more ions after reaction ofmetals in acidic pH solution [53]

e Rp and Rct values of samples are gradually decreasedand increased respectively as exposure periods increasede Rp is emphasizing due to resistance caused by in-homogeneity of the metal surface and it is decreased due tocorrosion e Rct is increased for SS plate and Ti-sprayedcoating due to protective nature of passive film while SSsprayed coating owing to deposition of corrosion productson surface e corrosion products and passive oxidefilm increase their thickness as exposure periods were in-creased resulting in high Rct than 1 h of exposure [63] ecapacitance of the metalcoating surface and passive filmcorrosion products is derived as Ceff1 and Ceff2 respectivelye Ceff1 is dramatically increased as Rp is decreased withexposure periods which indicates that the metalcoatingsurface started to corrode but as the Rct is increased Ceff2is decreased e Ceff2 result was attributed to that thesurface became homogenized due to formation of the passivelayer or corrosion products on the metalcoating interfaceafter 312 h of exposure However it is found that the Ceffis greater for SS coating than the Ti coating and SS plate inall exposure periods It indicates that the SS coating ismore inhomogeneous and defective than other samplese thickening of the oxide film was attributed to anodicoxidation and formation of the protective passivefilmcorrosion products that reduced the penetration ofaggressive ions [64] e corrosion product itself causedresistance to corrosion due to uniform and adherentdeposition

After 312 h of exposure W was observed for the SS platepossibly resulting from diffusion of the protective passivelayer on the surface [65 66] As exposure periods are in-creased the passive film strength also increased

Table 1 Electrochemical parameters of the SS plate SS-sprayed coating and Ti-sprayed coating extracted after fitting of EIS data to suitableEECs with different exposure periods in pH 4 solution

Time (h) 1 312Sample ID SS plate SS sprayed Ti sprayed SS plate SS sprayed Ti sprayedRs (kΩmiddotcm2) 677 520 864 502 537 845Rp (kΩmiddotcm2) 16600 1602 4819 2282 2015 2107CPE1Q1 (1times 10minus6) (Ωminus1middotcmminus2middotsn) 27 620 73 296 416 372n1 099 099 099 095 092 093

Ceff1 (microFmiddotcmminus2) 268 620 722 290 410 365Rct (kΩmiddotcm2) 1187 915 1097 35002 1156 4633CPE2Q2 (1times 10minus6) (Ωminus1middotcmminus2middotsn) 916 2523 1058 209 1561 385n2 075 044 054 091 046 060

Ceff2 (microFmiddotcmminus2) 9419 73172 12011 2544 31213 5662W (1times 10minus6) (Ωmiddotcm2middotsminus05) mdash mdash mdash 42 mdash mdash

Advances in Materials Science and Engineering 7

After 1 h of exposure Rp is found to be highest for allsamples due to a barrier type of protection exhibited by thecoatings e NiO Fe2O3 FeO and Cr2O3 thin lms areformed on the SS plate [42] which give the protection againstcorrosion Initially the metal or coating surface does notstart to react with solution resulting in high Rp but onceproper reaction has occurred the surfaces start to corrodeAt the time of corrosion initiation Rct will involve whichcauses resistance to penetration of the solution toward themetal surface erefore Rp is decreased and Rct is increasedas exposure periods are increased e lm formed on thesurfaces was imperfect and rough [67 68] after 1 h of ex-posure thus the dispersion coecient (n) is less for CPE2As the exposure periods were increased the Rct values in-creased and CPE decreased for passive layercorrosionproducts of the samples Rct is high for all samples due todeposition of corrosion products on SS-sprayed coating andthe protective passive layer on Ti-sprayed coatings and theSS plate after 312 h of exposure

342 Potentiodynamic Studies Potentiodynamic studieswere carried out after 312 h of exposure and results are shownin Figure 6e SS plate showed pitting andmany breakdownpotentials during anodic scanning e breakdown potentialsmay be caused by oxidation of the metal surface due toimpressed current which form a new phase or a metastablepassive lm that altered the passive lm properties [69]erefore there is a chance that another oxide phase couldform on the surface which might be protective in nature

e current density of the SS plate is lower than that of Tiand SS coatings during anodic scanning e interestingobservation is found in case of Ti and SS coatings that there isa gradual increase in anodic current density during anodicscanning It may be due to corrosion or transformation ofunstable oxide lms of these samples and whatever corrosionproductspassive lm formed was deposited on the surface

e anodic and passive corrosion current of the Ticoating was lower than that of the SS coating which meansthat in this case the former is more likely to form compactprotective and adherent passive oxide lms [70 71]

e passive lm of Ti-sprayed coating resisted the pen-etration of corrosive species of the solution thus the reducingcorrosion rate is observed During cathodic scanning allsamples exhibited hydrogen evolution reaction which dom-inated over the oxygen reduction reaction [72]

e electrochemical parameters were extracted aftertting of potentiodynamic plots to the Tafel region using theSternndashGeary equation

Icorr B

Rtotal (2)

e SternndashGeary constant (B) can be calculated byputting the values for corrosion current density (Icorr) andtotal polarization resistance (Rtotal) in (2) e extracted dataon the corrosion potential (Ecorr) Icorr Rtotal B and thecorrosion rate of samples after 312 h of exposure to pH 4solution are shown in Table 2

e Ecorr of the SS plate and SS and Ti coatings are 0138minus0594 and minus0403V versus AgAgCl respectively e SSplate exhibited nobler Ecorr than the Ti coating followed bythe SS coating

e nobler potential of the SS plate is due to formation ofthe Cr-enriched oxide lm whereas others exhibited theactive potential e active Ecorr of SS- and Ti-sprayedcoatings compared to the SS plate is attributed to thepresence of defects on the coating surface

Lai et al observed that when SS was exposed to H2SO4-contaminated water solution it formed NiO Fe2O3 FeOand Cr2O3 thin lms which were protective in nature andnoble [42] e active potential of SS coating was due to thepresence of defective or porous oxidecorrosion lms thatmade the sample more susceptible to corrosion and exhibitthe mixed potential [73]

e studied pH solution was acidic and led tothe deterioration of the samples During exposure theformed corrosion products deposited on the sample surfacee corrosion products blocked the defectspores of thesamples and resisted the penetration of the solution [74 75]

e iron oxides were more active and therefore exhibitedthe active potential e Ti coating exhibited a nobler po-tential than SS coating because it had only ne and elongatedcracks (Figure 2(c)) which stied the aggressive species ofthe solution from reaching the base metal In contrast the SScoating contains many connected pores and valley mor-phology where the acidic solution can accumulate and in-duce crevice corrosion

ese results indicate that the passive lm formed on theTi-sprayed coating after exposure to pH 4 solution is pro-tective nonporous compact and resistant to the penetrationof aggressive ions in the solution e SS coating has porousand nonprotective corrosion productsiron oxides

e Rtotal values of the SS plate SS-sprayed coating andTi-sprayed coating are 379860 33792 and 68464 kΩmiddotcm2respectively e higher Rtotal value of Ti coating comparedto the SS coating suggests that it can be used as a coating to

Ecorr

Ecorr

Ecorr

Icorr Icorr Icorrndash09

ndash06

ndash03

00

03

06

09

12

E(V

) ver

sus A

gA

gCl

1E ndash 8 1E ndash 7 1E ndash 6 1E ndash 5 1E ndash 41E ndash 9

Log I (A∙cm2)

SS plateSS sprayedTi sprayed

Figure 6 Potentiodynamic plots of the SS plate and sprayedcoatings in pH 4 solution after 312 h of exposure (1mVs)

8 Advances in Materials Science and Engineering

protect thematerials in H2SO4-contaminated water solutioneven at low pH e B values were calculated by using (2)and it was found that the SS plate and Ti-sprayed coatingwere identical and less active while SS-sprayed coatingshowed 067V which is more pronounced to corrosion [76]e B value of the SS plate and Ti-sprayed coating is underthe active control while the SS-sprayed surface exhibits activedissolution values which influence the corrosion phenomenae calculated Icorr value of SS-sprayed samples reveals theactiveness of coating while the SS plate and Ti-sprayedcoating control the corrosion process in acidic solution atlonger duration of exposure

e corrosion rate (micrommiddotyminus1) was calculated by the fol-lowing equation [77]

Corrosion rate microm middot yminus11113872 1113873 327 times Icorr times EW

d (3)

e corrosion rate in (3) is expressed in micrometres peryear (micromyear) and Icorr in microAmiddotcmminus2 e Icorr was obtainedby dividing the total surface area of the working electrodeunder the corrosion current (microA) EW represents theequivalent weight (gmiddotmolminus1) and d is the density (gmiddotcmminus3)

e corrosion rate of the SS coating is 266043 micrommiddotyminus1and is greater than that of the SS plate and Ti coating by 5184 and 623 times respectively is result indicates that theSS is not an effective coating material for deposition by thearc thermal spray process in pH 4 solution and long durationof exposure

e corrosion rate data of the SS coating revealed that ittotally dissolvedcorroded down to the base substrate einitial coating thickness was 200 microm while the corrosion ratewas 266043 micrommiddotyminus1 us it may be reported that the Ticoating was effective in protecting the surface than the SScoating e Ti can be used as a coating material to protectthe waste water reservoir and extend its service life

343 Characterization of Corrosion Products after Poten-tiodynamic Studies in pH 4 by Different Techniques emorphology of corrosion products was examined by SEMand results are shown in Figure 7 On the SS plate surfacethe passive film was adherent uniform and regularlydeposited thus preventing the penetration of solution(Figure 7(a))e edges of the surface show few cracks causedby the destructive potentiodynamic experiment and thepassive film prevented the cracking After potentiodynamicstudies the SS plate surface did not show any other type ofcorrosion productsrust

e SS coating exhibited different sizes of corrosionproduct morphology withmicropore formation (Figure 7(b))e net-like microstructure of corrosion products is

attributed to the presence of porous iron oxides roughthe net and thread morphologies the acidic solution easilypenetrated the substrate and formed corrosion products

e morphology of corrosion products formed on the Ticoating was totally different from that on the SS plate andsprayed coating e passive films formed on the Ti-sprayedsurface exhibit microcracks plate and globular morphology(Figure 7(c)) e globular particles block the micro- andmacrocracks on the top surface erefore enhanced cor-rosion resistance was observed after 312 h of exposure thanon SS-sprayed coating

Passive oxide films of Ti coating contain plate-like mi-crostructures that were uniformly deposited on the surfaceSimilar morphologies were not observed in the corrosionproducts of the SS plate and sprayed coating

e phases present in the corrosion products of allsamples after potentiodynamic studies were studied by XRDe identification of phases in corrosion products is shownin Figure 8 e SS plate exhibits the presence of tetrataenite(FeNi) and Fe It is reported that FeNi is unstable and candeteriorate into other forms if it exposes for long term tolow-temperature environments [78]

e presence of lepidocrocite (c-FeOOH) in the corrosionproducts of SS-sprayed coatings confirmed that this coatingwas susceptible to corrosion in acidic solution However Ticoating exhibits composite oxides along with Ti and TiOerefore the improved corrosion resistance of Ti-sprayedcoating is observed by formation of TiO2 (rutile and anatase)and this observation corroborates with EIS and potentiody-namic resultse passive oxides of Ti such as TiO2 and Ti3O5have formed e TiO2 is thermodynamically more stablethan others [79] erefore the Ti-sprayed coating is at-tributed to improved corrosion resistance properties ofcoating in H2SO4 solutione transformation of Ti into TiO2in the H2SO4 environment is well documented elsewhere[80 81] TiO3 and some amount of TiO (Figure 3) may betransformed into TiO2 and Ti3O5 due to a strong oxidizingability of H2SO4 solution us corrosion productspassivefilm of Ti-sprayed coating exhibits some peaks of TiO (Fig-ure 8)erefore corrosion is observed after 312 h of exposureto H2SO4 solution Once proper transformation of Ti and TiOinto the stable form occurred then the corrosion rate wouldbe completely suppressed

4 Conclusions

From the above results and discussion the following can beconcluded

(1) e EIS and potentiodynamic studies revealed theprotective properties of Ti coating due to formation

Table 2 Electrochemical parameters extracted after fitting of potentiodynamic plots to the Tafel region

Sample IDElectrochemical parameters

Ecorr (V) versus AgAgCl Icorr (microAmiddotcmminus2) Rtotal (kΩmiddotcm2) B (V) Corrosion rate (micrommiddotyminus1)SS plate 0138 0382 379860 015 5132SS sprayed minus0594 19803 33792 067 266043Ti sprayed minus0403 1913 68464 013 42703

Advances in Materials Science and Engineering 9

of the protective oxide lm at longer duration ofexposure to acidic solution

(2) e improved corrosion resistance properties of Ti-sprayed coating than SS-sprayed coating after 312 hof exposure to acidic solution is attributed totransformation of unstable oxides into stable pro-tective and adherent TiO2 (rutile and anatase) whichis a thermodynamically stable oxide

(3) Examination of the corrosion product morphology bySEM revealed the compact globular and crystalline

corrosion productsoxide lms on the Ti samplewhile the SS sample formed defective andmicrocrack-bearing corrosion products

(4) e SS plate showed uniform crack-free passivelms with no trace of corrosion products after 312 hof exposure to acidic solution

Conflicts of Interest

e authors declare no conicts of interest

Authorsrsquo Contributions

Jitendra Kumar Singh and Jin-ho Park conducted the ex-periments and wrote the initial draft of themanuscript Han-Seung Lee designed the experiments Jitendra Kumar Singhand Han-Seung Lee analyzed the data and wrote the nalmanuscript Han-Seung Lee Mohamed A Ismail andJitendra Kumar Singh reviewed and contributed to the nalrevised manuscript All authors contributed to the analysisof the data and read the nal paper

Acknowledgments

is research was supported by the Korea Ministry of En-vironment (MOE) as Public Technology Program basedon Environmental Policy (no 2015000700002) and BasicScience Research Program through the National ResearchFoundation of Korea (NRF) funded by the Ministry ofScience ICTand Future Planning (no 2015R1A5A1037548)

10 20 30 40 50 60 70 80 90

TiO

2-rut

ileTiTiTi

O2-a

nata

seTi

O2-r

utile

TiO

2-rut

ileTi

O2-r

utile

Ti

Ti TiO

2-rut

ile

TiO

2-ana

tase

TiOTi

3O5

Ti3O

5Ti

3O5

Ti3O

5

Ti3O

5 Ti3O

5

Fe

Fe Fe

FeN

iFeN

i

FeN

i

SS sprayed

SS plate

Ti sprayed

TiO

2-rut

ile

FeN

i

2θ (degree)

FeN

i

Fe FeN

i

Fe

TiO

Inte

nsity

(CPS

)

γ-Fe

OO

Hγ-

FeO

OH

γ-Fe

OO

H

Figure 8 XRD of the SS plate and sprayed coatings after poten-tiodynamic studies in pH 4 solution (05degmin)

(a)

Micropores

(b)

Micropores

Globular

(b)

Figure 7 SEM images of corrosion products formed on the (a) SS plate (b) SS-sprayed coating and (c) Ti-sprayed coating afterpotentiodynamic studies in pH 4 solution

10 Advances in Materials Science and Engineering

Supplementary Materials

Figure S1 Nyquist plots (at higher frequency ranges) of theSS plate and sprayed coatings in pH 4 solution after 1 h ofexposure (100 kHz to 40 kHz) Figure S2 KramersndashKronigtransformation of the EIS data obtained for the SS plate andsprayed coatings in pH 4 solution after (a) 1 h and (b) 312 h(100 kHz to 001Hz) (Supplementary Materials)

References

[1] H S Jensen P N L Lens J L Nielsen et al ldquoGrowth kineticsof hydrogen sulfide oxidizing bacteria in corroded concretefrom sewersrdquo Journal of Hazardous Materials vol 189 no 3pp 685ndash691 2011

[2] M Lupsea L Tiruta-Barna and N Schiopu ldquoLeaching of haz-ardous substances from a composite construction productndashAnexperimental and modelling approach for fibre-cement sheetsrdquoJournal of Hazardous Materials vol 264 pp 236ndash245 2014

[3] Q Guo ldquoIncreases of lead and chromium in drinking waterfrom using cement-mortar-lined pipes initial modelling andassessmentrdquo Journal of Hazardous Materials vol 56 no 1-2pp 181ndash213 1997

[4] E Owaki R Okamoto and D Nagashio ldquoDeterioration ofconcrete in an advanced water treatment plantrdquo in Concreteunder Severe Condition Environment and Loading E GjorvE Odd K Sakai and N Banthia Eds E amp F N Spon LondonUK 1998

[5] R N Swamy and S Tanikawa ldquoAn external surface coating toprotect concrete and steel from aggressive environmentsrdquoMaterials and Structures vol 26 no 8 pp 465ndash478 1993

[6] D Crowe and R Nixon ldquoCorrosion of stainless steels in wastewater applicationsrdquo 2016 httpwwwhweaorgwp-contentuploads201507150204_Corrosion_of_Stainless_Steels_in_Wastewater_Applicationspdf

[7] B B Bhalerao and S J Arceivala ldquoApplication of corrosioncontrol techniques in municipal water and waste water engi-neeringrdquo 2016 httpeprintsnmlindiaorg58251129-139PDF

[8] ldquoAlkalinity profiling in wastewater operations ops challengelaboratory event 2015rdquo 2017 httpwwwrmweaorgdocsAlkalinity_Profiling_in_Wastewater_Operations_White_Paper_OPS_2015_ED_12015pdf

[9] V Kumar ldquoProtection of steel reinforcement for concretea reviewrdquo Corrosion Reviews vol 16 no 4 pp 317ndash358 1998

[10] A I Fernandez-Abia J Barreiro D Gonzalez-Madruga andL N Lopez de Lacalle ldquoEffect of mechanical pre-treatments inthe behavior of nanostructured PVD-coated tools in turningrdquoInternational Journal of Advanced Manufacturing Technologyvol 73 no 5ndash8 pp 1119ndash1132 2014

[11] S Rodrıguez-Barrero J Fernandez-Larrinoa I AzkonaL N Lopez de Lacalle and R Polvorosa ldquoEnhanced per-formance of nanostructured coatings for drilling by dropleteliminationrdquo Materials and Manufacturing Processes vol 31no 5 pp 593ndash602 2016

[12] L Pawlowski Be Science and Engineering of Bermal SprayCoatings John Wiley amp Sons Ltd West Sussex UK 2ndedition 2008

[13] G Jandin H Liao Z Q Feng and C Coddet ldquoCorrelationsbetween operating conditions microstructure and mechan-ical properties of twin wire arc sprayed steel coatingsrdquo Ma-terials Science and Engineering A vol 349 no 1-2pp 298ndash305 2003

[14] H S Lee J K Singh M A Ismail and C BhattacharyaldquoCorrosion resistance properties of aluminum coating applied

by arc thermal metal spray in SAE J2334 solution with ex-posure periodsrdquo Metals vol 6 no 3 pp 1ndash15 2016

[15] H S Lee J K Singh and J H Park ldquoPore blocking char-acteristics of corrosion products formed on aluminum coatingproduced by arc thermal metal spray process in 35 wt NaClsolutionrdquo Construction and Building Materials vol 113pp 905ndash916 2016

[16] H S Lee J H Park J K Singh and M A Ismail ldquoProtectionof reinforced concrete structures of waste water treatmentreservoirs with stainless steel coating using arc thermalspraying technique in acidified waterrdquoMaterials vol 9 no 9pp 1ndash20 2016

[17] H B Choe H S Lee and J H Shin ldquoExperimental study onthe electrochemical anti corrosion properties of steel struc-tures applying the arc thermal metal spraying methodrdquoMaterial vol 7 no 12 pp 7722ndash7736 2014

[18] A Guenbour A Benbachir and A Kacemi ldquoEvaluation ofthe corrosion performance of zinc-phosphate-painted carbonsteelrdquo Surface and Coatings Technology vol 113 no 1-2pp 36ndash43 1999

[19] N Cinca C R C Lima and J M Guilemany ldquoAn overview ofintermetallics research and application status of thermalspray coatingsrdquo Journal of Materials Research and Technologyvol 2 no 1 pp 75ndash86 2013

[20] D F Bettridge and R G Ubank ldquoQuality control of high-temperature protective coatingsrdquo Materials Science andTechnology vol 2 no 3 pp 232ndash242 1986

[21] H D Steffens Z Babiak and M Wewel ldquoRecent de-velopments in arc sprayingrdquo IEEE Transactions on PlasmaScience vol 18 pp 974-975 1990

[22] H A M Muhamad S N Hayati A S Kiyai andM S N Binti ldquoCritical process and performance parameter ofthermal arc spray coatingsrdquo International Journal of MaterialsEngineering Innovation vol 5 no 1 pp 12ndash27 2014

[23] J R Davis Surface Engineering for Corrosion and Wear Re-sistance ASM International Geauga County OH USA 2001

[24] KS F4716 Cement Filling Compound for Surface PreparationKorean Agency for Technology and Standards (KATS) SeoulKorea 2001

[25] S Shrestha and A J Sturgeon ldquoUse of advanced thermal sprayprocesses for corrosion protection in marine environmentsrdquoSurface Engineering vol 20 no 4 pp 237ndash243 2004

[26] L Wang and J Sun ldquoMolybdenum modified AISI 304stainless steel bipolar plate for proton exchange membranefuel cellrdquo Journal of Renewable and Sustainable Energy vol 5no 2 p 021407 2013

[27] M Dadfar M H Fathi F Karimzadeh M R Dadfar andA Saatchi ldquoEffect of TIG welding on corrosion behavior of316L stainless steelrdquo Materials Letters vol 61 no 11-12pp 2343ndash2346 2007

[28] J Liu F Chen Y Chen and D Zhang ldquoPlasma nitridedtitanium as a bipolar plate for proton exchange membranefuel cellrdquo Journal of Power Sources vol 187 no 2 pp 500ndash504 2009

[29] X Cheng and S G Roscae ldquoCorrosion behaviour of titaniumin the presence of calcium phosphate and serum proteinsrdquoBiomaterials vol 26 no 35 pp 7350ndash7356 2005

[30] J Pouilleau D Devilliers F Garrido S Durand-Vidal andE Mahe ldquoStructure and composition of passive titaniumoxide filmrdquo Materials Science and Engineering B vol 47no 3 pp 235ndash243 1997

[31] S Kumar T S N Narayanan S G Raman and S K Seshadrildquoermal oxidation of cp-Ti evaluation of characteristics andcorrosion resistance as a function of treatment timerdquo

Advances in Materials Science and Engineering 11

Materials Science and Engineering C vol 29 no 6pp 1942ndash1949 2009

[32] J E Sundgren P Bodo and I Lundstrom ldquoAuger electronmicroscopic studies of the interface between human tissueand implants of titanium and stainless steelrdquo Journal ofColloid and Interface Science vol 110 no 1 pp 9ndash20 1984

[33] C J Goodacre G Bernal K Rungcharassaeng and J Y KanldquoClinical complications with implant and implant prosthesisrdquoJournal of Prosthetic Dentistry vol 90 no 2 pp 121ndash1322003

[34] S Gudic J Radosevic andM Kliskic ldquoStudy of passivation ofAl and Al-Sn alloys in borate buffer solution using electro-chemical impedance spectroscopyrdquo Electrochimica Actavol 47 no 18 pp 3009ndash3016 2002

[35] F J Martin G T Cheek W E OrsquoGrady and P M NatishanldquoImpedance studies of the passive film on aluminiumrdquoCorrosion Science vol 47 no 12 pp 3187ndash3201 2005

[36] Y J Liu Z Y Wang andW Ke ldquoStudy on influence of nativeoxide and corrosion products on atmospheric corrosion ofpure Alrdquo Corrosion Science vol 80 pp 169ndash176 2014

[37] V Maurice W P Yang and P Marcus ldquoXPS and STM studyof passive films formed on Fe-22Cr (110) single-crystal sur-facesrdquo Journal of Be Electrochemical Society vol 143 no 4pp 1182ndash1200 1996

[38] A Goossens and D D Macdonald ldquoA photoelectrochemicalimpedance spectroscopic study of passive tungstenrdquo Journalof Electroanalytical Chemistry vol 352 no 1-2 pp 65ndash811993

[39] D D Macdonald E Sikora and G Engelhardt ldquoCharac-terizing electrochemical systems in the frequency domainrdquoElectrochimica Acta vol 43 no 1-2 pp 87ndash107 1998

[40] H Song and D D Macdonald ldquoPhotoelectrochemical im-pedance spectroscopy I Validation of the transfer function byKramers-Kronig transformationrdquo Journal of Be Electro-chemical Society vol 138 no 5 pp 1408ndash1410 1991

[41] A Baron W Simka and W Chrzanowski ldquoEIS tests ofelectrochemical behaviour of Ti6Al4V and Ti6Al7Nb alloysrdquoJAMME vol 21 pp 23ndash26 2007

[42] W Y Lai W Z Zhao Z F Yin and J Zhang ldquoEIS and XPSstudies on passive film of AISI 304 stainless steel in dilutesulfuric acid solutionrdquo Surface and Interface Analysis vol 44no 4 pp 418ndash425 2012

[43] R T Loto ldquoPitting corrosion evaluation of austenitic stainlesssteel type 304 in acid chloride mediardquo Journal of Materialsand Environmental Science vol 4 pp 448ndash459 2013

[44] V Mitrovic-Scepanovic and R J Brigham ldquoe localizedcorrosion of stainless steel in high purity sulphate solutionsrdquoCorrosion Science vol 27 no 6 pp 545ndash553 1987

[45] A Fattah-alhosseini and S Vafaeian ldquoPassivation behavior ofa ferritic stainless steel in concentrated alkaline solutionsrdquoJournal of Materials Research and Technology vol 4 no 4pp 423ndash428 2015

[46] J B Wen J L Ma and J G He Al-Base Sacrificial AnodeMaterial for Corrosion Protection Chemical Industry PressBeijing China 2012

[47] C Liu Q Bi and A Matthews ldquoEIS comparison perfor-mance of PVD TiN and CrN coated mild steel in 05 N NaClaqueous solutionrdquo Corros Sci vol 43 pp 1953ndash1961 2001

[48] O de Rincon A Rincon M Sanchez et al ldquoEvaluating Zn Aland Al-Zn coatings on carbon steel in a special atmosphererdquoConstruction and Building Materials vol 23 no 3pp 1465ndash1471 2009

[49] M M Verdian K Raeissi and M Salehi ldquoCorrosion per-formance of HVOF and APS thermally sprayed NiTi

intermetallic coatings in 35 NaCl solutionrdquo CorrosionScience vol 52 no 3 pp 1052ndash1059 2010

[50] D Yang C Liu X Liu M Qi and G Lin ldquoEIS diagnosis onthe corrosion behavior of TiN coated NiTi surgical alloyrdquoCurrent Applied Physics vol 5 no 5 pp 417ndash421 2005

[51] Y C Xin J Jiang K F Huo G Y Tang X B Tian andP K Chu ldquoCorrosion resistance and cytocompatibility ofbiodegradable surgical magnesium alloy coated with hydro-genated amorphous siliconrdquo Journal of Biomedical MaterialsResearch Part A vol 89 no 3 pp 717ndash726 2009

[52] H Y Ha and T H Lee ldquoDetermining factors for the pro-tectiveness of the passive film of FeCrN stainless steel formedin sulfuric acid solutionsrdquo Corrosion Science and Technologyvol 12 no 4 pp 163ndash170 2013

[53] J K Singh and D D N Singh ldquoe nature of rusts andcorrosion characteristics of low alloy and plain carbon steelsin three kinds of concrete pore solution with salinity anddifferent pHrdquo Corrosion Science vol 56 pp 129ndash142 2012

[54] C Boissy C Alemany-Dumont and B Normand ldquoEISevaluation of steady-state characteristic of 316L stainless steelpassive film grown in acidic solutionrdquo ElectrochemistryCommunications vol 26 pp 10ndash12 2013

[55] T Balusamy M Jamesh S Kumar and T S N SankaraNarayanan ldquoCorrosion resistant Ti alloy for sulphuric acidmedium suitability of TindashMo alloysrdquo Materials and Corro-sion vol 63 pp 803ndash806 2012

[56] T P Cheng J T Lee and W T SAI ldquoPassivation of titaniumin molybdatendashcontaining sulphuric acid solutionrdquo Electro-chimica Acta vol 36 no 14 pp 2069ndash2076 1991

[57] H Luo C Dong K Xiao and X Li ldquoe passive behaviour offerritic stainless steel containing alloyed tin in acidic mediardquoRSC Advances vol 6 no 12 pp 9940ndash9449 2016

[58] A Fattah-alhosseini and S Vafaeian ldquoInfluence of grainrefinement on the electrochemical behavior of AISI 430ferritic stainless steel in an alkaline solutionrdquo Applied SurfaceScience vol 360 pp 921ndash928 2016

[59] A Fattah-alhosseini H Elmkhah and F R Attarzadeh ldquoOnthe electrochemical behavior of PVD Ti-coated AISI 304stainless steel in borate buffer solutionrdquo Journal of MaterialsEngineering and Performance vol 26 no 4 pp 1792ndash18002017

[60] B A Boukamp ldquoPractical application of the KramersndashKronigtransformation on impedance measurements in solid stateelectrochemistryrdquo Solid State Ionics vol 62 no 1-2pp 131ndash141 1993

[61] B Hirschorn M E Orazem B Tribollet V Vivier I Frateurand M Musiani ldquoDetermination of effective capacitance andfilm thickness from constant-phase-element parametersrdquoElectrochimica Acta vol 55 no 21 pp 6218ndash6227 2010

[62] G J Brug A L G van den Eeden M Sluyters-Rehbach andJ H Sluyters ldquoe analysis of electrode impedances com-plicated by the presence of a constant phase elementrdquo Journalof Electroanalytical Chemistry and Interfacial Electrochemis-try vol 176 no 1-2 pp 275ndash295 1984

[63] E O Mayne and C L Page ldquoGreen corrosion inhibitortheory and practicerdquo British Corrosion Journal vol 7 p 1151972

[64] M Nagayama and S Kawamura ldquoAnodic oxidation of ferrousion on passive ironrdquo Electrochimica Acta vol 12 no 8pp 1109ndash1119 1967

[65] Q Mohsen and S A Fadl-Allah ldquoImprovement in corrosionresistance of commercial pure titanium for the enhancementof its biocompatibilityrdquo Materials and Corrosion vol 62no 4 pp 310ndash319 2011

12 Advances in Materials Science and Engineering

[66] Q G Jiang Q Miao W P Liang et al ldquoCorrosion behavior ofarc sprayed AlndashZnndashSindashRE coatings on mild steel in 35 wtNaCl solutionrdquo Electrochimica Acta vol 115 pp 644ndash656 2014

[67] B Cox and Y M Wong ldquoSimulating porous oxide films onzirconium alloysrdquo Journal of NuclearMaterials vol 218 no 3pp 324ndash334 1995

[68] A Al-Negheimish A Alhozaimy R R Hussain R Al-ZaidJ K Singh and D D N Singh ldquoRole of manganese sulfideinclusions in steel rebar in the formation and breakdown ofpassive films in concrete pore solutionsrdquo Corrosion vol 70no 1 pp 74ndash86 2014

[69] W Lai W Zhao F Wang C Qi and J Zhang ldquoEIS study onpassive films of AISI 304 stainless steel in oxygenous sulfuricacid solutionrdquo Surface and Interface Analysis vol 41 no 6pp 531ndash539 2009

[70] A Singh B P Singh M R Wani D Kumar J K Singh andV Singh ldquoEffect of anodization on corrosion behaviour andbiocompatibility of Cp-titanium in simulated body fluidrdquoBulletin of Materials Science vol 36 no 5 pp 931ndash937 2013

[71] M Jamesh T S N Sankara Narayanan and P K Chuldquoermal oxidation of titanium evaluation of corrosion re-sistance as a function of cooling raterdquo Materials Chemistryand Physics vol 138 no 2-3 pp 565ndash572 2013

[72] B Jegdic D M Drazic and J P Popic ldquoCorrosion potentialof 304 stainless steel in sulfuric acidrdquo Journal of the SerbianChemical Society vol 71 no 5 pp 543ndash551 2006

[73] D Dzhurinskiy E Maeva E Leshchinsky and R G MaevldquoCorrosion protection of light alloys using low pressure coldsprayrdquo Journal of Bermal Spray Technology vol 21 no 2pp 304ndash313 2012

[74] A Meroufel and S Touzain ldquoEIS characterization of newzinc-rich powder coatingsrdquo Progress in Organic Coatingsvol 59 no 3 pp 197ndash205 2007

[75] C M Abreu M Izquierdo M Keddam X R Novoa andH Takenouti ldquoElectrochemical behavior of zinc-rich epoxypaints in 3 NaCl solutionrdquo Electrochimica Acta vol 41no 15 pp 2405ndash2415 1996

[76] C Andrade and J A Gonzalez ldquoQuantitative measurementsof corrosion rate of reinforcing steels embedded in concreteusing polarization resistance measurementsrdquo Materials andCorrosion vol 29 no 8 pp 515ndash519 1978

[77] S W Dean ldquoElectrochemical methods of corrosion testingrdquoin Electrochemical Techniques for Corrosion R Baboian EdNACE Houston TX USA 1977

[78] Z Wu H Bei F Otto G M Pharr and E P GeorgeldquoRecovery recrystallization grain growth and phase stabilityof a family of FCC-structured multi-component equiatomicsolid solution alloysrdquo Intermetallics vol 46 pp 131ndash140 2014

[79] R Bansal J K Singh V Singh D D N Singh and P DasldquoOptimization of oxidation temperature for commerciallypure titanium to achieve improved corrosion resistancerdquoJournal of Materials Engineering and Performance vol 26no 3 pp 969ndash977 2017

[80] Z J Liu X Zhong J Walton and G E ompson ldquoAnodicfilm growth of titanium oxide using the 3-electrode electro-chemical technique effects of oxygen evolution and mor-phological characterizationsrdquo Journal of Be ElectrochemicalSociety vol 163 no 3 pp E75ndashE82 2016

[81] M A Selimin Z Malik N Anjang M I Idris andH Z Abdullah ldquoEffect of sulphuric acid concentration onanodised titanium for biomedical applicationrdquo in Proceedingsof the Bird International Conference on Advances in CivilStructural and Mechanical Engineering-CSM pp 46ndash50Birmingham UK April 2015

Advances in Materials Science and Engineering 13

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

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