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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?
