Composite Materials A novel interesting field Rui Zhang

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: Al 2 O 3 + Y 2 O 3 (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) + SiO 2 TiO 2 + SiO 2 CNT + Nano Ag T1T1 T2T2  1. Energetic cells: Functional uses: energetic, sensitive, smart etc. 2. Luminescent materials: Al 2 O 3 -Eu 2 O 3 -SrCO 3 3. Environmental materials: thermoelectric materials (for military uses and for wild researches)

4. Sensors: more sensitive, accuracy P O2 (1) P O2 (2) Exhausted gas  ZrO 2 -Y 2 O 3 clean the air other sensors of humidity, light, distance, toxic gases

6. Smart items PTC Piezoelectrics: nano robot 5. Electronics: substrates: AlN + Al; Al 2 O 3 + Al; SiC + Cu; etc high thermal-releasing property capacitors: BaTiO 3 + BN; PbTiO 3 + PbMg 1/3 Nb 2/3 O 3 ; SiTiO 3 + PbTiO 3 ; etc high dielectric property with low losses SiC + Al 2 O 3 + MgO + SiO 2

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): toto to observe the morphologies Transmission electron microscope (TEM) toto to examine the bonding structures of different phases High resolution TEM (HRTEM) toto to observe the atomic arrangement at the boundary

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40 nm Cu 2 O Cu

Auger microscope (AES): to detect the surface elements. Energy dispersion spectra (EDS) to determine the elements

Thermal analysis Differential scanning calorimetry (DSC), Thermogravimetry (TG), Mass spectroscopy (MS) to measure the thermodynamic behaviour useful for determination of heat treatment profile temperature, heating rate, protective atmosphere etc.

O2O2 CO 2

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?