Multiphased Ceramic Materials

In many fields of thermomechanical applications, such as advanced gas turbine, thermal protection of space planes, oil and coal electric generation, advanced brake devices, etc. high performance materials are needed. Lacking of toughness and reliability, monolithic ceramics had reached their limits and multi-phase - terials are expected as the most promising candidates. Apart from the impro- ment on the thermomechanical performance, more than one function, such as magnetic, electrical and optical functions, can be incorporated simultaneously into the multi-phase material. However, several key problems remained to be solved in the near future. These problems include microstructure complexity, process challenge, machining ability and the most important cost issue. Fourteen scientists from 9 leading research - stitutes across Taiwan Strait are invited to give their view and experimental e- dence on solving the above problems. These reports highlight the principles of - signing delicate microstructure and novel processing routes. The potential of improving machining ability is also demonstrated. However, the most critical cost problem remained to be solved. In light of the economic surge in China in recent years, the market demands more technology breakthrough. The market can accept value-added products. It further indicates the importance of developing of multi-phase materials with multi-functions. Along with the market growth, the cost problem will be solved soon as the mass production technology becoming available.

A new concept for the design of ceramic composite materials and their fabrication and processing is presented in this book

Texte du rabat

The book summarizes the recent progress in ceramics research. Several novel concepts for materials selection and microstructural design are presented, as are experimental results that substantiate the ideas. These newly designed materials include multiphase ceramic composites of three phases with strengths of 1000 MPa and toughnessof 10 MPam0.5. They can be fabricated to mimic the macrostructure of wood and are machineable because of their novel microstructure.

Contenu
1 Multi-phase Materials.- 1.1 Introduction.- 1.2 The Basic Concept of Multi-phase Materials.- 1.3 The Need for Multi-phase Materials.- 1.4 Research Objectives.- References.- 2 New Concepts in the Design of Tough Ceramics.- 2.1 Introduction.- 2.2 Experiments.- 2.3 Results and Discussion.- 2.4 Conclusions.- Acknowledgement.- References.- 3 Interface Design of Tough Ceramics: Si3N4/BN Fibrous Monolithic Ceramic.- 3.1 Introduction.- 3.2 Measurement of Interfacial Toughness.- 3.3 Preparation of Si3N4/BN Fibrous Monolithic Ceramic.- 3.4 Conclusions.- Acknowledgement.- References.- 4 Microstructural Design : Si/SiC Composites Derived from Wood.- 4.1 Introduction.- 4.2 Experimental Work.- 4.3 Results and Discussion.- Acknowledgements.- References.- 5 Microstructure through Design in-situ Seeding Technique.- 5.1 Introduction.- 5.2 Experimental Work.- 5.3 Results and Discussion.- 5.4 Summary and Conclusions.- Acknowledgements.- References.- 6 Directional Solidification : ZrB2-LaB6 Eutectic Composites.- 6.1 Introduction.- 6.2 Experimental Work.- 6.3 Results and Discussion.- 6.4 Conclusions.- Acknowledgements.- References.- 7 A Co-Sedimentation Technique to Fabricate Continuous Gradient Composites.- 7.1 Introduction.- 7.2 Physical Modeling.- 7.3 Numerical Modeling.- 7.4 Results and Discussions.- 7.5 Validation of the Model.- 7.6 Conclusions.- Acknowledgements.- References.- 8 Spark Plasma Sintering : A Promising New Technique and its Mechanism.- 8.1 Introduction.- 8.2 Experimental Work.- 8.3 Results.- 8.4 Discussion.- 8.5 Conclusions.- Acknowledgments.- References.- 9 Pulsed Chemical Vapor Infiltration : Carbon/SiC Nanocomposites.- 9.1 Introduction.- 9.2 Experimental Work.- 9.3 Results and Discussion.- 9.4 Summary.- Acknowledgements.- References.- 10 Metal Oxidation Process : NiAl/Al2O3 Composites.- 10.1 Introduction.- 10.2 Experimental Work.- 10.3 Results and Discussion.- 10.4 Conclusions.- Acknowledgment.- References.- 11 Co-electroplating Nano-ceramic Particulates with Ni Layer.- 11.1 Introduction.- 11.2 Experimental Procedures.- 11.3 Results and Discussion.- 11.4 Conclusions.- References.- 12 Hot-Pressing Technique : SiC/AlN Composites.- 12.1 Introduction.- 12.2 Applications of Silicon Carbide Ceramics.- 12.3 SiC/AlN Particulate Composites.- 12.4 Conclusions.- Acknowledgements.- References.- 13 Nondestructive Evaluation of Strength and Residual Stress using Sphere Indentation.- 13.1 Introduction.- 13.2 Effect of Stress Gradient on Fracture.- 13.3 Critical Issues and Local Strength.- 13.4 Experimental Work.- 13.5 Proof Tests of Strength.- 13.6 Discussions and Conclusions.- Acknowledgements.- References.- 14 Machinable Ceramic Graded Composites.- 14.1 Introduction.- 14.2 Basic Design Principles.- 14.3 Machinable Graded Si3N4/h-BN Composite.- 14.4 Machinable Graded Al2O3/LaPO4 Composite.- 14.5 Conclusions.- References.- 15 Future of Structural Multi-phase Ceramics.- 15.1 Obstacles for the Applications of Ceramics.- 15.2 Novel Materials.- 15.3 Challenges.- References.