Technical ceramic materials offer tremendous potential in a wide variety of engineering applications. Their unique blend of physical, chemical, and mechanical properties provide innovative design opportunities for advanced concepts such as low-heat rejection engines, high-efficiency gas turbines, high temperature bearings, and high-speed, high-precision cutting tools. Unfortunately, many of the critical friction and wear (tribological) properties of advanced ceramics are not well defined or understood. Research in materials science of advanced ceramics is developing very rapidly. As materials change and new materials are constantly being developed, the evaluation of these materials for tribological applications becomes a critical issue. This paper explores several important considerations in friction and wear testing of ceramic materials. Detailed test sample characterization is required to define the materials pair. Sample preparation, selection of load and speed, environmental control, and contamination effects are crucial to the meaningful tribological evaluation of ceramic materials. Specific examples are given using a modified four-ball wear tester with alumina specimens.

encouraged and sponsored graduate cooperative programs in which promising young scientists (some of them NBS staff members) come to NBS to conduct research, part of which often becomes the graduate's thesis.While it is not the objective of NBS to teach and train graduate students , such a program often furthers NBS programmatic goals by attracting high caliber scientists working on areas where NBS mission lies. Many excellent research papers have results and many students, upon graduation, have chosen to stay at NBS to continue their research careers.Such programs also draw many first rate university professors to NBS through the participation of these students in NBS research programs and projects, thus fostering NBSuniversity interactions and enhancing the scientific caliber of the work and reputation at NBS and the participating university. At the same time, through the frequent contacts that NBS has with industries, a natural university/government lab/industry relationship evolves, bringing a team focus on many research projects of significant economic and/technological impacts. When appropriate, the students were supported by ECUT for some time.To this, we gratefully acknowledge the generous support of DOE ECUT, without whose support many ideas would not be explored.Stephen M. Hsu Chief, Ceramics Division ABSTRACT High temperature ceramic tribology is one of the fastest growing and least understood areas in tribology. The need to understand the mechanisms of friction and wear for ceramic materials is critical.Ceramic materials are being utilized in tool development, bearing design, materials development for low-heat-rejection diesels, automotive gas turbines, Stirling engines, and aerospace applications. Recommendations for future work on high temperature wear mechanisms of ceramic materials and the tribological testing of such materials are presented at the conclusion of this work.