Popis: |
High-temperature, structural application of ceramics often involves ceramic-ceramic and metal-ceramic interfaces. Chipping and cracking often occur in such applications as heat engines at interfaces where aerodynamic loads and differential thermal movement produce simultaneous normal and tangential forces. A hypothesis of the chipping mechanism will be presented, as will experimental results from a test apparatus designed to evaluate interface compatibility. Results include the influence of contact geometry, temperature, load, dwell time at temperature, lubricants, and interface layers on the static and dynamic coefficient of friction and on material strength. |