presentation of procast casting simulation

MECHANICAL PROPERTIES UNDER CONSIDERATION

• Hardness• Tensile strength• Ductility

COMPOSITION OF ALUMINUM ALLOY LM 25:

Chemical composition

Copper 0.15-0.2

Magnesium 0.20-0.65

Silicon 6.5-7.5

Iron 0.45-0.55

Manganese 0.35

Nickel 0.15

Zinc 0.15

Lead 0.15

Tin 0.05

Titanium 0.05-0.25

Aluminum Remainder

Aluminium casting alloys

• Alloy designations:• (i) Aluminium Association (AA) system.• (ii) Aluminium Association casting Tamper

Designation system.• (iii) American National Standards Institute

(ANSI ): • (iv) The UNS Alloy Designation System

Contd………..

• (v)DIN AND ISO SYSTEM

For example, 6181=AlSi1Mg0.8

Variation of Mechanical properties with percentage composition of constituent element

• Composition Grouping:There are 7 basic groups…….• Aluminum- copper (2xx)• Aluminum- silicon- copper (3xx)• Aluminum-silicon-magnesium (3xx)• Aluminum- silicon (4xx)• Aluminum- magnesium (5xx)• Aluminum- zinc-magnesium (7xx)• Aluminum-tin (8xx)

Aluminum-Copper

Aluminum-Copper have been used extensively in wrought and cast form where strength and toughness are required. These alloy exhibit

strength and hardness at room and elevated temperatures

Alloy of this types are susceptible to solidification cracking and to interdendritic shrinkage.

Copper-containing aluminum alloys are less resistance to corrosion and may be susceptible to

stress-corrosion

Aluminum-Silicon-Copper

• Copper contributes to strengthening and machinability and silicon improves castability and reduces hot shortness

• Al-Si-Cu alloys with less than 5-6% Cu are heat-treatable, if Mg is added then heat-treatment response is enhanced

Aluminum-Silicon-Magnesium

• Excellent properties after heat treatment, high Corrosion resistance, and a low level of thermal expansion

• While not as strong as high-strength Al-Cu and Al-Si-Cu alloys.

Aluminium-Silicon

• Binary aluminium-silicon alloys exhibit excellent fluidity, castability, and corrosion resistance. These alloys display low strength and poor machinability

• The strength, ductility, and castability of hypoeutectic Al-Si alloys can be further improved by modification of Al-Si eutectic through the controlled addition of sodium and/ or strontium

Aluminium-Magnesium

• Single phase binary alloys with moderate to high strength and toughness

• Most important characteristics is the corrosion resistance including exposed to sea-water and marine application

• Excellent weldability , machinability and attractive appearance

• But they require greater control of temperature gradient

• Mg in Al-alloys increases the oxidation rates

Aluminium-Zinc-Magnesium

• Rapid solidification in these alloys can result in microsegretion of magnesium-zinc phases that reduces hardening potential.

• The cost of heat-treatment, high residual stress levels and distortion are avoided

• The castability of Al-Zn-Mg alloys is poor, and good foundry practices are required to minimize hot tearing and shrinkage defects

Aluminium-Tin• Tin is the major alloying element in compositions developed

for bearing application.• Alloys containing 5.0 to 7.0% Sn are broadly used in bearings

and bushing in which low friction, compressive strength, fatigue strength, and resistance to corrosion are important criteria

• Their light weight minimize loads in reciprocating and heat dissipation improves bearing life

• Al and tin are essentially immiscible before and after solidification, tin is present in dispersed form

• Parts may be plastically cold worked to improve compressive yield strength .

Effects of Alloying Elements

(i) Antimony• 0.10%, antimony refines the aluminum-silicon

eutectic.• But a distinctly lamellar eutectic rather than a fine

fibrous structure• It reacts with sodium or strontium to form coarse

intermetallics with adverse effects on castability and metallurgical structure

• Antimony is a heavy metal with potential of toxicity and associated with stibine gas (SbH3) formation

(ii) Beryllium• Additions of a few parts per million beryllium can be

effective in reducing oxidation losses• At higher concentrations (>0.04% ), beryllium affects the

form and composition of iron-containing intermetallics, markedly improving strength and ductility

• Changing the morphology of the insoluble phase from plate to nodular, beryllium changes its composition, rejecting Mg from the Al-Fe-Si complex and thus permitting its full use for hardening purposes

(iii) Bismuth, Lead, and Cadmium • Bi,Pb, and Cd addition improves the

machinability of cast aluminum alloys, at concentrations greater than 0.1%

(iv) Boron

• Boron combines with other metals to form borides, such as AlB2 and TiB2

• Titanium boride forms stable nucleation sites that interact with active grain-refining phases such as TiAl3 for grain refinement

• Metallic borides reduce tool life and form coarse inclusions with detrimental effects on strength and ductility.

• Borides also contribute to sludging, the precipitation of intermetallics from liquid solution in furnaces .

• Boron treatment with Titanium, Vanadium, Zirconium improve purity and conductivity in electrical applications (Rotor).

(v) Sodium • Sodium modifies the Al-Si eutectic. In the

absence of phosphorus, recovered concentration of 0.01% are effective

• Sodium at less than 0.005% is embrittling in Al-Mg alloys

• Sodium is rapidly lost in molten Al through its high vapour pressure

• Sodium increases surface tension and through addition methods can increase hydrogen content

a) Al-13wt%Si phase diagram and Micrograph

b) Al-13wt%Si-0.01%Na phase diagram and micrograph

(vi) Strontium

• Strontium modifies the Al-Si eutectic. In the absence of phosphorus, recovered concentration range of 0.008% to 0.04% are effective

• Lower concentrations are effective with higher solidification rates

• Higher addition levels are associated with casting porosity

(vii) Phosphorus • As AlP3, phosphorus nucleates and refines

primary silicon-phase formation in hypereutectic Al-Si alloys

• it coarsens the eutectic structure in hypereutectic Al-Si alloys and diminishes the effectiveness of common modifiers

(viii) Tin • Tin is effective in improving antifriction

characteristics and is used in bearing applications.it also improves machinability

(ix) Titanium • Titanium is extensively used to refine grain

structure• TiB2 is necessary grain refinement

(x) Chromium• Chromium typically forms the compound

CrAl3, which display extremely limited solid solubility and is therefore useful in suppressing grain-growth tendencies

• It improves corrosion resistance

a) Without grain refinement b) With grain refinement

Effects of Major Alloying Elements

(i) Silicon• Improvement of casting characteristics • Fluidity, hot tear resistance and feeding characteristics• For slow cooling rate processes such as plaster, investment, and sand,

the preferred range is 5 to 7%, for permanent mold 7 to 9%, and for die casting 8 to 12%

• It combines with Mg and forms an intermetallic compound MgSi2

• Al-Si alloys differ from our "standard" phase diagram in that aluminium has zero solid solubility in silicon at any temperature. This means that there is no beta phase and so this phase is "replaced" by pure silicon (you can think of it as a beta phase, which consists only of silicon).

• Therefore, for Al-Si alloys, the eutectic composition is a structure of alpha+Si rather than alpha+beta

Phase Diagram of Al-Si

(ii) Magnesium • Mg is the basic for strength and hardness development in

heat treated Al-Si alloys and is commonly used in more complex Al-Si alloy containing Cu, Ni and some other elements for same purpose

• The intermetallic compound MgSi2 which acts as a hardening phase display a useful solubility limit corresponding to 0.7% Mg, beyond which either no further strengthening occurs or matrix softening take place

• For high strength Al-Si alloys the range for Mg is between 0.4 to 0.07%

Variation of tensile properties with Mg%

2 4 6 80

50

100

150

200

250

300

350

400

450

0.0% Mn, tensile strength0.1% Mn,tensile strength0.5% Mn, tensile strength0.0% Mn,yield stength0.1% Mn, yield strength0.5% Mn, yield strenth

Mg %

Stre

ngth

MPa

Elongation vs Mg percentage for 1.3mm thick plate

2 4 6 80

5

10

15

20

25

30

35

40

0.1% Mn0.5% Mn0.9% Mn

Mg %

Elon

gatio

n (in

2in

)%

(iii) Copper • It improves strength and hardness in the cast and heat treated

conditions• Alloys containing 4 to 5.5% Cu respond most strongly to

thermal treatment • It reduces corrosion resistance and increases stress-corrosion • It reduces hot tear resistance and increases the potential for

interdendritic shrinkage • Aluminum-copper alloy containing 2 to 10% copper, generally

with other addition, forms important families of alloy. Both cast and wrought aluminum-copper alloys responds to solution heat treatment and subsequent aging with increase in strength and hardness and decrease in elongation.

Variation of tensile properties with copper content

(iv) Iron• Iron improves hot-tearing resistance and

decreases the tendency for die sticking or soldering in die casting .

• Increases in iron content decreased ductility• The intermateilic phases FeAl3, FeMnAl6, and

α-AlFeSi. These insoluble phases are responsible for strength, especially at elevated temperature, but also embrittlement of the microstructure

Effect of Iron plus Silicon impurities on Tensile properties of Al

0 0.2 0.4 0.6 0.8 10

20

40

60

80

100

120

Yield strengthTensile strength

Iron + Silicon %

STRE

NGT

H, M

Pa

(v) Manganese

• In the absences of work-hardening, Mn offers no significant in cast Al-alloys

• High-volume fraction of MnAl6 in alloy containing more than 0.5% Mn may beneficially influence internal soundness

Variation of tensile properties of Al-alloy with Mn %

0 0.5 1 1.5 2 2.50

50

100

150

200

250

300

350

400

450

500

Yield strength (Mpa)

Tensile strength (Mpa)

Elongation (x0.1mm)

Mn %

STRE

NGT

H, M

Pa

(vi) Zinc• Zinc offers no significant benefits in aluminium

casting• Addition of Cu and/ or Mg, however, zinc

results in attractive heat-treatable composition

• Up to 3% Zn in die casting compositions allows the use foe lower-grade and wrought alloy scrap

Variation of tensile properties for Al-Mg alloy with Zn

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

yield strength-1%Mg

Tensile strength-1%Mg

yield strength-3%Mg

Tensile strength-3%Mg

Zn %

STRE

NGT

H, M

Pa

CASTING

• Sand Casting• Sand casting is the simplest method of casting

aluminium. Sand is made into a mould by forming around a wooden "pattern". The pattern is removed, the sand mould assembled and molten metal poured in. The process is chosen for small production runs, for complex shape castings requiring intricate cores or for very large castings

Sand Casting

Gravity Die-Casting

• Castings are produced by pouring molten metal into permanent metal moulds. It is generally made from cast iron. This process produces ‘ Chill Castings’

Gravity Die-Casting

Low Pressure Die-Casting

• This is a repetitive process where identical parts are cast by injecting molten metal under low pressure into metal dies. This process requires complex machinery and is similar to high pressure die-casting

Low Pressure Die-Casting

High Pressure Die- casting

• High pressure die- casting is a repetitive process for casting identical parts by injecting Aluminium into metal moulds at pressures in the order of 1000psi. Complex machinery and expensive tooling is required for this process. It is characterized by very good surface finish and dimensional consistency. The advantage of this system includes fast cycle times and the convenience of melting the metal in the casting machine.

High Pressure Die- casting

Diesel Furnace

• A diesel furnace is a piece of equipment that produces heat by burning diesel. The diesel used to power the furnace can be of petroleum origin. It is used to make casting specimens. We used a K- type thermocouple to measure the temperature. Temperature Range – 0 to 1100 ºC. We also used a multi channel temperature indicator for mesuring casting temperature.

• The highest temperature that can be obtained in a diesel furnace (in workshop) is 950ºC. The temperature required to melt LM 25 alloy was around 700ºC to 750ºC. It took around 20- 25 minutes to melt the material. After that we took it to a crusible(refractory container) and with the help of laddle we poured the molten metal into the mould. It took 2-3 days to solidify the molten metal and the specimen was obtained. The specimen was mad using three dies- sand, graphite and metal.

Prepared Specimen

BHN values comparision- graphite˂ metal˂sand

CASTING SIMULATION USING PROCAST

FIRST ITERATIONCAST SPECIMEN SPECIFICATION. One test bars with dimensions of 12mm diameter, 52mm gage

length. Cast material is LM25. Two circular section of 20 mm diameter and length 20 mm,

test section diameter 12 mm and 52 mm gauge length. Top gate is designed for this iteration.

CASTING DESIGN.

PROCESS PARAMTER SPECIFICATION

Parameter’s Magnitude

Metal velocity 0.1 m/sec

Casting pressure 1 atm (101325 pa )

Ambient temperature 30 deg Celsius

Film coefficient between casting and mould

100 w/m*m*k

Melt temperature 715 deg Celsius

Die Material Sand Silica

Casting metal Al_AlSi7Mg

TET MESH GENERATION

PRECAST INITIALIZED.

CASTING MATERIAL ASSIGN

MOULD MATERIAL ASSIGN

DEFINING RUN PARAMTER

PROCAST SOLVER

FILL TIME

INTERPRETATION OF RESULT

THIS SHOWS THE TIME WHICH IS REQUIRED FOR THE MOLTEN METAL TO REACH AT A PARTICULAR

POINT. WE CAN KNOW AFTER WHAT TIME MOLTEN METAL

WILL REACH AT THE INTERESTED POINT. IT IS USED FOR THE PREDICTION OF CATING YIELD, IF

FILL TIME FOR A POINT IS MORE THAN THE SOLIDIFICATION TIME OF EARLY POINT IN GATEING SYSTEM THEN THAT POINT WILL REMAIN

EMPTY.

FRACTION SOLID AT 70 SEC

INTERPRETATION OF RESULTTHIS RESULT PREDICTES THE MASS

PERCENTAGE OF SOLID.THIS TELL’S HOW MUCH PERCENTAGE

OF SOLID IS PRESENT AT A GIVEN TIME.LINK FOR ANIMATION.

PRESSURE VARIATIONAT 0.51 SEC

INTERPRETATION OF RESULT.

THIS WILL TELL WHAT IS THE PRESSURE AT EACH SECTION AT A GIVEN TIME.

THE VARIATION OF PRESSURE DIRECTLY INFLUSENCE THE GRAIN SIZE AND HENCE MECHANICAL PROPERTIES.

THE GRAIN SIZE CAN PREDICTED FROM THE PRESSURE AT A POINT.

LINK FOR ANIMATION.

MOULD TEMPERATURE AT 190 SEC

INTERPRETATION OF RESULTTHIS PREDICTES THE VARIATION OF MOULD

TEMPERATURE WITH TIME.THE POINTS WHERE THE TEMPERATURE

REACHES HIGH VALUE WHICH CAN CAUSE HARM TO FOUNDRYMAN.

LINK FOR ANIMATION.

AIR ENTRAPMENT AT 0.57 SEC


THIS TELL’S THE ENTRAPED AIR AT A GIVEN TIME

THIS RESULT CAN BE USED TO PREDICT THE LOCATIONS WHERE AIR CAVITY CAN BE PRESENT IN CASTING.

AIR OR GAS VENT’S CAN BE PROVIDED AT SUITABLE LOCATIONS WHERE THIS AIR ENTRAPMENT IS OCCURING.

LINK FOR ANIMATION.

SOLIDIFICATION TIME.

INTERPRETATION OF RESULTIT PREDICT THE SOLIDIFICATION TIME OF

EVERY POINT.THE MAXIMAM SOLIDIFICATION TIME AND

MINIMUM SOLIDIFICATION TIME CAN BE FOUND OUT.

IF THE SOLIDIFICATION TIME OF A POINT IS LESS THAN THE FILL TIME OF A POINT AFTER IT THEN THE RESULTING CASTING WILL HAVE VOIDS.

TEMPERATURE Vs TIME GRAPH.

INTERPRETATION OF RESULTTHIS GRAPH IS PLOTED BETWEEN TEMPERATURE

AND TIME.THIS GRAPH IS FOR NODAL GAP OF 50.EACH CURVE SHOWS THE TEMPARATURE

VARIATION OF A PARTICULAR NODE WITH TIME.THIS GRAPH WILL BE USED TO KNOW THE

TEMPARATURE OF A PARTICULAR NODE.GRAPH TELL THE TEMPARATURE AT EACH POINT

IN CASTING AND MOULD.LINK FOR ANIMATION.

TEMPARATURE VARIATION OF A NODE

INTERPRETATION OF RESULTTHIS GRAPH SHOWS THE VARIATION OF

TEMPARATURE OF A NODE WHICH IS IN CASTING WITH TIME AND HENCE ITS SOLIDIFICATION RATE CAN BE FOUND OUT.

SOLIDIFICATION RATE INFLUENCE THE HARDNESS.

FRACTION SOLID WITH TIME


THIS GRAPH SHOWS THE FRACTION SOLID WITH NODAL GAP OF 50.

IN ASINGLE GRAPH ALL THE POINT IN CASTING ARE PLOTED WITH THERE FRACTION SOLID WITH TIME.

VOID CREATED AFTER SOLIDIFICATION


AFTER THE SOLIDIFICATION OF CASTING THERE WILL BE A VOID AT TOP MOST PORTION.

VOID OCCURRED BECAUSE THE MOLTEN METAL AT TOP SOLIDIFES AT LAST.

THIS CAN BE AVOIDED WITH PROVIDING A SPUR OF SOME EXTRA HEIGHT.

POROSITY


THIS RESULT CAN TELL US ABOUT THE LOCATION WHERE POROSITY WILL OCCUR.

POROSITY IS A MEASURE OF THE VOID SPACES IN MATERIAL, AND IS A FRACTION OF THE VOLUME OF VOIDS OVER THE TOTAL VOLUME, BETWEEN 0 TO 1 OR AS A PERCENTAGE BETWEEN 0 TO 100.

LINK FOR ANIMATION.

CONCLUSION FOR DESIGNTHIS DESIGN WHICH HAVE TOP GATEING SYSTEM

WILL HAVE SHRINKAGE CAVITY, VELOCITY OF MOLTEN METAL WILL CAUSE SAND INCLUSION.

THIS DESIGN HAS DRAWBACKS OF VOID CREATION, SHRINKAGE POROSITY, FILL TIME OF SOME SECTION ARE MORE THAN THE SOLIDIFACTION TIME OF PREVIOUS POINTS.

NOW WE KNOW WHERE CASTING WILL HAVE DEFECTS, SO WE CAN GO FOR A DESIGN WHICH CAN OVER COME IT.

SECOND ITERATION.

SAME CASTING SPECIMEN SPECIFICATION AS FIRST ITERATION.

THE GATING SYSTEM USED IS BOTTOM GATE.

DEISGN OF CASTING.







20 w/m*m*k


Die Material REFRACTORY GRAPHITE MOULD.


VELOCITY OF MOLTEN METAL

INTERPRETATION OF RESULTTHIS SHOWS THE VELOCITY PROFILE AND ITS

MAGNITUDE AND HENCE THE EFFECT ON MOULD BECAUSE OF MOLTEN METAL FLOW.

FRACTION SOLID AT T=2.58 SEC


AT THE TIME 2.58 SEC THE MOULD IS NOT COMPLETELY FILLED AND TILL THAT TIME ALL THE MOLTEN METAL IS AT SAME POURING TEMPARATURE BECAUSE THE MOULD IS A REFACTORY MATERIAL WITH VERY LESS FILM COEFFICIENT BETWEEN INTERFACE.

VOID CREATION AT TIME 2.58 SEC


SINCE DURING THE TIME OF 2.58 SEC THE MOULD IS NOT COMPLETELY FILLED HENCE THERE WILL BE A VOID AT THAT TIME.

THIS VOID MAY NOT BE THERE IF SIMULATION IS RUNNED FOR MORE TIME.

TEMPARATURE VARIATION


SINCE THE MOULD IS A BAD CONDUCTOR OF HEAT SO THERE WILL BE VERY LESS HEAT TRANSFER TO SURROUNDING AND MOLTEN METAL WILL BE AT TEMPERATURE OF POURING FOR TIME 2.58 SEC.

VARIATION OF TEMPARATURE.


THERE IS VERY LESS TEMPARATURE VARIATION IN BOTH CASTING AND MOULD BECAUSE THE MOULD MATERIAL IS BAD CONDUCTORE OF HEAT.

THIS RESULT IS ONLY TILL TIME 2.58 SEC.

CONCLUSION.SO FAR TILL TIME OF 2.58 SEC THERE IS

PROPER MOULD FILLING.NOTHING CAN BE CONCLUDED FROM

THIS SIMULATION BECAUSE THE TIME OF SIMULATION IS NOT ENOUGH TO FILL THE MOULD COMPLETELY.

BUT THERE IS WASTAGE OF MATERIAL IN SPUR AND ALSO IT IS DIFFICULT TO REMOVE THE RUNNER AND SPUR FROM CASTING.

ITERATION THIRD.

CAST SPECIMEN SPECIFICATION. ONE TEST BARS WITH DIMENSIONS OF 12MM

DIAMETER, 52MM GAGE LENGTH. CAST MATERIAL IS LM25. TWO CIRCULAR SECTION OF 20 MM DIAMETER

AND LENGTH 20 MM, TEST SECTION DIAMETER 12 MM AND 52 MM GAUGE LENGTH.

BRANCHED GATE IS DESIGNED FOR THIS ITERATION.

CASTING DESIGN.







20 w/m*m*k


Die Material Refractory graphite


TEMPARATURE VARIATION.

AT TIME 30.8 SEC.

AT TIME 30.8 SEC.

AT TIME 160 SEC.

AT TIME 160 SEC.

TEMPATURE Vs TIME

AIR ENTRAPMENT.

FRACTION SOLID AT T= 40 SEC

FRACTION SOLID Vs TIME.

PROSOITY.

SOLIDIFICATION TIME.

FILL TIME.

CONCLUSION.

THIS DESIGN IS BETTER THAN OTHER AS THERE IS UNIFORM SOLIDIFICATION TIME FOR CASTING.

STANDARDIZATION

• We need to standardize the data of LM25 using the instruments available in the campus so that we can compare this data with the enhanced alloy to be produced. Standardization or standardization is the process of developing and agreeing upon technical standards. A standard is a document that establishes uniform engineering or technical specifications, criteria, methods, processes, or practices. Some standards are mandatory while others are voluntary. Voluntary standards are available if one chooses to use them. Some are de facto standards, meaning a norm or requirement which has an informal but dominant status. Some standards are de jure, meaning formal legal requirements. Formal standards organizations, such as the International Organization for Standardization (ISO) or the American National Standards Institute, are independent of the manufacturers of the goods for which they publish standards

Metallographic Specimen Preparation

Specimen Preparation• The first step in specimen preparation is selection and

separation of samples from the bulk material (sampling) is of special importance. If the choice of a sample is not representative of the material, it cannot be corrected later.it is also difficult to compensate later for improper sectioning, because additional ,time consuming corrective steps are necessary to remove the initial damage.

• Sectioning should render a plane surface for the following preparation without causing critical changes in the material

Mounting• Mounting of specimens is usually necessary to allow them

to be handled easily.it also minimizes the amount of damage likely to be caused to the specimen itself.

• The mounting material used should not influence the specimen as a result of chemical reaction or mechanical stresses.it should adhere well to the specimen ,and if the specimen is to be electro polished later in the preparation then the mounting should also be electrically conducting

• A mounted specimen usually has a height half its diameter, to prevent rocking during grinding and polishing. The polishing edges of the mounting specimen should also be rounded to minimize the damage to grinding and polishing discs.

Grinding• Surface layers damaged by cutting must be removed by grinding.

Mounted specimens are ground with rotating discs of abrasive paper, for example wet silicon carbide paper. The coarseness of the paper is indicated by a number: the number of grains of silicon carbide per square inch. So, for example, 180 grit paper is coarser than 1200 grit.

• The grinding procedure involves several stages, using a finer paper (higher number) each time. Each grinding stage removes the scratches from the previous coarser paper. This can be easily achieved by orienting the specimen perpendicular to the previous scratches. Between each grade the specimen is washed thoroughly with soapy water to prevent contamination from coarser grit present on the specimen surface. Typically, the finest grade of paper used is the 1200, and once the only scratches left on the specimen are from this grade

Polishing• Polishing discs are covered with soft cloth impregnated with

abrasive diamond particles and an oily lubricant or water lubricant. Particles of two different grades are used : a coarser polish-typically with diamond particles 6 microns in diameter which should remove the scratches produced from the finest grinding stage, and a finer polish-typically with diamond particles 1 micron in diameter, to produce a smooth surface. Polishing wheel the specimen should be wasted thoroughly with warm soapy water followed by alcohol to prevent contamination of the disc. The drying can be made quicker using a hot air drier.

•Mechanical polishing will always leave a layer of distributed material on the surface of the specimen. Electro polishing or chemical polishing can be used to remove this, leaving an undisturbed surface

Specimen after grinding

HARDNESS TEST• The Brinell hardness test is used to measure the hardness

of the composites. The Brinell hardness test method consist of indenting the test material with a 10 mm diameter hardness steel ball subjected to a load of 500 kg for softer materials. The full load is normally applied for at least 30 seconds. The diameter of the indentation left in the test material is measured with low powered microscope. The average of two reading of the diameter of impression at right angle should be made. Surface on which the indentations is made be smooth and free from dirt or scale. The brinell hardness number is calculated by dividing the load applied by the surface area of the indentation.

Hardness Test Using Brinell Hardness Testing Machine

• BHN =• Where • P is applied load (kg)• D : is diameter of the ball (mm)• d : is diameter of the indentation (mm)


TYPES OF MOULD BHN DIAMETER OF INDENTATION (d in mm)

SAND 60 3.213METAL 58 3.267GRAPHITE 56 3.323

OBTAINED RESULTApplied load, P = 500 KgMaterial of Indentor : carbon steelDiameter of Indentor , D = 10mm


Universal Measuring Microscope

SURFACE ROUGHNESS

• Surface roughness is measure of the finer surface irregularities in the surface texture. These are results of the manufacturing process employed to create the surface. Surface roughness Ra is rated as the arithmetic average deviation are large, the surface is rough; if they are small the surface is smooth. Roughness is typically considered t be the frequency, short wavelength component of a measured surface.

• The surface roughness of the machined composites is measured by using profilometer

Measurement of surface roughness using surface profilometer.

OBTAINED DATARa is the arithmetic average of the absolute values and Ry is the range of the collected

roughness data points

SAND MOULD GRAVITY MOULD

METAL MOULD

Ra Ry Ra Ry Ra Ry

13.55 75.62 4.04 26.26 7.39 50.16

13.77 76.74 3.65 24 7.91 63.23

11.51 60.35 4.13 23.32 8.84 65.67

9.56 54.67 5.48 30.31 6.91 43.27

10.93 61.68 6.98 38.21 7.46 52.36

12.6 72.68 5.61 34.64 8.48 64.67

11.33 62.21 6.51 41.49 7.73 51.36

13.23 71.24 5.78 31.22 6.68 42.36

THANK YOU

presentation of procast casting simulation

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