Composite Materials A novel interesting field Rui Zhang zhangray@zzu

Composite Materials

A novel interesting field

Rui Zhang

zhangray@zzu.edu.cn

What do we want?

1. The most advanced information

2. The most useful technique

3. The most practical training

Outline

1. What are Composite Materials?

2. New Uses for Composites

3. How to make Composites?

4. What can we learn from the study on Composites?

5. What left for us to do in the coming study ?

6. What can we be in our future?

What are Composite Materials

Composites: Art and Science making and using materials

those did not appear until several years ago, and those do not

exit now and will be discovered in the future

composed of at least 2 different kinds of materials

1. Ceramics + Ceramics:

Al2O3 + Y2O3 (YAG): transparent, new laser generator

2. Ceramics + Organics: SiC + resin

3. Ceramics + Metals (Cermet): Diamond + Co

New Uses of Composites

Structural Uses: stronger, more flexible, more reliable

protective composite coating

1. In rocketry and missile:

2. In jet aircraft:

nose cone to withstand extreme temperatures

4. Reinforcement clusters: (Cu +SiC)/ Fe, Al etc.

high speed cutting, polishing

3. Machining tools:

Porous composites

Carbon Nano Tube (CNT) + SiO2

TiO2 + SiO2

CNT + Nano Ag

T1

T2

1 . Energetic cells:

Functional uses: energetic, sensitive, smart etc.

2. Luminescent materials: Al2O3-Eu2O3-SrCO3

3. Environmental materials:

thermoelectric materials (for military uses and for wild

researches)

4. Sensors:

more sensitive, accuracy

PO2 (1)PO2 (2)

Exhausted gas

ZrO2-Y2O3

clean the air

other sensors of humidity, light, distance, toxic gases

6. Smart items

PTC

Piezoelectrics: nano robot

5. Electronics:

substrates: AlN + Al; Al2O3 + Al; SiC + Cu; etc

high thermal-releasing property capacitors: BaTiO3 + BN; PbTiO3 + PbMg1/3Nb2/3O3;

SiTiO3 + PbTiO3; etc

high dielectric property with low losses

SiC + Al2O3 + MgO + SiO2

How to make Composites?

1. Powder preparation: even co-dispersion

Mechanical method, Chemical method

2. Forming: pressing, extrusion, casting

3. Firing: the key process

Conventional sintering,

Hot-pressing,

Vacuum sintering

What can we learn from the study on Composites?

Advanced Theories :

• Chemistry and physics at high temperature

• Mechanical theories

• Microstructure theory

• Quantum theory (nanometer materials, superconductor)

• Electric, luminescent, magnetic, and thermal theories

• Other interdisciplinary theories

advanced techniques :

• The most advanced processing apparatus

Microwave sintering:

915 MHz or 2450 MHz

volumetric heating, energy-saving, clean, rapid

(0.5 h)

Spark plasma sintering (SPS):

high pulsed current, rather rapid (10 min)

Advanced analysis technology

X-ray diffraction (XRD):

to identify the phases.

Scanning electron microscope (SEM): to

to observe the morphologies

Transmission electron microscope (TEM) to

to examine the bonding structures of different phases

High resolution TEM (HRTEM) to

to observe the atomic arrangement at the boundary

back

back

back

40 nm

Cu2O

Cu

Cu Cu

Cu

Auger microscope (AES):

to detect the surface elements.

Energy dispersion spectra (EDS)

to determine the elements

0 1 2 3 4

0

200

400

600

CuOC

Si

Inte

nsity

/ cp

s

Energy / KeV

Thermal analysis

Differential scanning calorimetry (DSC), Thermo

gravimetry (TG),

Mass spectroscopy (MS)

to measure the thermodynamic behaviour

useful for determination of heat treatment profile

temperature, heating rate, protective atmosphere et

c.

50 150 250 350 450 550 650 750 850 950-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

Temperature / oC

DSC

/ m

W/m

g

95

96

97

98

99

100

101

TG

DSC

Wei

ght /

%

50 150 250 350 450 550 650 750 850 9500

40

80

120

160

200

240

Ion

curr

ent /

10-1

1 A

Temperature / oC

O2

CO2

What left for us to do in the coming study ?

Confidence!

Diligence !

Devotion !

Success and development !

What can we be in our future?

Scientists of Materials Science.

Engineers of Materials Engineering.

Researchers of Advanced materials

Bosses of Materials Enterprise.

Professors of Materials Science and Engineering

Senior Employee(Superintendent) in foreign corporation

Nobel Prize Winner: Prof. Kroto insists:

Doubt and Question

are the two prerequisites to do scientific researches

Thank you for your attention

and Any questions?