Progress in Nitrogen Ceramics

The first NATO Advanced Study Institute on Nitrogen Ceramics held in 1976 at Canterbury came at a particularly significant moment in the development of this subject. The five-year period, 1971-75, had been an especially fruitful one in very many respects for work in the areas of covalent materials in general, and of the nitrides in particular. The Institute was therefore able to cap­ ture fully the spirit of excitement and adventure engendered by the outputs of numerous national research programmes, as well as those of many smaller research groups, concerning ceramics potent­ ially suitable for applications in a high temperature engineering context. It reflected accurately the state of knowledge with respect to the basic science, the powder technology, and the prop­ erties of materials based on silicon nitride and associated syst­ ems. The Proceedings of the Institute thus provided a good record for workers already in the field, and a useful textbook for new­ comers to the subject of nitrogen ceramics. The Canterbury Advanced Study Institute had a valuable educ­ ational and social function in bringing together for two weeks a large proportion of those workers most closely involved at that time with the nitrogen ceramics. The atmosphere of this meeting, providing both intensive discussions and informal contacts, made a lasting impression on the participants, and inevitably the question was raised of whether, and when, a second Advanced Study Institute might be held on this subject.

General Introduction.- Nitrogen Ceramics 1976–1981.- Section A Crystal Chemistry.- (R) Silicate Structures and Atomic Substitution.- (R) The Characterization of ?’-sialons and the ?-? relationships in sialons and silicon nitrides.- The Structural Characterization of Sialon Polytypoids.- Section B Thermodynamics.- Calculation of Phase Equilibria in Systems Based on Silicon Nitride.- Phase Equilibrium Studies in Silicon Nitride — Metal Oxides Systems.- Solid-Liquid Reactions in Part of the System Si-Al-Y-N-0.- High Temperature Reactions and Microstructures in the Al203-AlN System.- Section C Formation Processes.- Silicon Nitridation.- The Effect of Silicon Particle Size on the Nitriding Behaviour of Reaction Bonded Silicon Nitride Compacts.- An Experimental Plan for the Nitridation of Si +Al Compacts.- Preparation of Silicon Nitride from Silica.- On the Preparation of Fine Silicon Nitride Powders.- Section D Structural Development.- Liquid Phase Sintering.- Sintering of Silicon Nitride, A Review.- Influence of Powder Properties and Processing Parameters on the Sintering of Silicon Nitride.- Sintering of Silicon Nitride-Based Materials using the Powder Bed Technique.- Densification and Transformation Mechanisms in Nitrogen Ceramics.- Sintering of Reaction Bonded Silicon Nitride.- Microstructure of Densified Reaction Bonded Silicon Nitride.- Sintering of Aluminium Nitride with Low Oxide Addition.- Stress Assisted Hot Formation of Ceramics.- Influence of Composition and Process Selection on Densification of Silicon Nitride.- A Gas Pressure Sintering Process for Producing Dense Silicon Nitride.- Hot Pressing of Aluminium Nitride.- Section E Vitreous State.- Structure-Property Relationships of the Vitreous State.- The Preparation and Properties of Oxynitride Glasses.- The Crystallization Behaviour of a Mg-Si-0-N Glass.- Thermodynamics of Grain Boundary Glass Crystallization (Abstract).- Section F Microstructure.- The Microstructure of Nitrogen Ceramics.- Evaluation of Microstructure in ?’-Sialon Materials by TEM Methods and its Correlation to Some Properties.- Sialon X-Phase.- Microstructure Development in Silicon Nitride.- Contribution of the Strength-Porosity Relationship in Reaction-Bonded Silicon Nitride.- Section G Chemical Interactions.- The Kinetics of Gas-Solid Reactions and Environmental Degradation of Nitrogen Ceramics.- Thermodynamics of Cation Diffusion through an Intergranular Phase: Application to Environmental Reactions with Nitrogen Ceramics.- Oxidation of Hot-Pressed Silicon Nitride.- Oxidation Behaviour of ?’-Sialons in Oxygen and Carbon Dioxide.- Metallic Infiltration of Reaction Bonded Silicon Oxide.- Brazing of Silicon Nitrides.- Section H Mechanical and Physical Properties.- High Temperature Deformation and Fracture Phenomena of Polyphase Silicon Nitride Materials.- Time-Temperature Effects in Nitride and Carbide Ceramics.- High Temperature Fatigue Failure in Pressureless Sintered Silicon Nitride.- Effect of Deformation on the Fracture of Si3N4 and Sialon.- Cyclic Fatigue Behaviour of Ceramics.- The Fracture Behaviour of Hot-Pressed Silicon Nitride between Room Temperature and 1400°C.- Parameter Studies on the Oxidation and the Strength Behaviour of Silicon Nitride.- Characterization, Oxidation and Mechanical Behaviour of Reaction-Bonded Silicon Nitride.- Creep and Internal Oxidation of Reaction Bonded Silicon Nitride.- Influence of Corrosion and Microstructure on the Mechanical Properties of Si-Y-O-N Ceramics.- Thermal Properties and Thermal Shock Resistance of Nitrogen Ceramics.- Thermal Shock Resistance of two Nitrogen Ceramics.- Non-Destructive Failure Prediction in Ceramics.- Non-Destructive Evaluation of Ceramic Gas Turbine Components by X-rays and other Methods.- Surface Damage in Ceramics: Implications for Strength Degradation, Erosion and Wear.- Contact Stresses at Ceramic Interfaces.- Section I Applications.- Sintering Properties and Fabrication of Si3N4/ Y203-Based Ceramics.- Lucas Syalons: Composition, Structure, Properties and Uses.- The Nature of SiC for Use in Heat Engines as Compared to Si3N4: An Overview of Property Differences.- Fabrication of Complex Shaped Ceramic Articles by Slip Casting and Injection Molding.- Hot Isostatic Pressing of Ceramics.- Section J National Research Programmes.- U.S. National Programmes in Ceramics for Energy Conversion.- Status Report 1981 on the German BMFT-Sponsored Programme “Ceramic Components for Vehicular Gas Turbines”.- Nitrogen Ceramics in France.- Current Japanese Research Programmes into Nitrogen Ceramics (presented by K. Suzuki).- Survey and Conclusions.- Concluding Remarks.- Author Index.- Index of Crystal Structures.- Index of Systems and Sub-Systems.