T his book is the product of an ongoing effort to understand and articulate the power of information superiority in warfare from a Joint perspective. This work would not have been possible without the support, encouragement, and cooperation of ASD(C3I) and the J6. We would like to acknowledge the direct and substantive contributions by: Vice Admiral Arthur K. Cebrowski, USN; LTG Douglas D. Buchholz, USA (Retired); and Lt Gen John L. Woodward, USAF. Many individuals have worked with us on numerous drafts. Included among those who have contributed comments and suggestions that have greatly enhanced this book are (in alphabetical order): Chuck

Environmental SEM tribometry of the pressureless-sintered Hexoloy a-SiC ceramics was continued in 0.2 and 3.4 Torr partial pressures of oxygen (P0 2) at room temperature (RT) to 950°C, coupled with after-test SEM photomicrography and AES/XPS surface analyses of the wear scars and the adjacent (unused) surfaces. The results show some correlation in the somewhat improved friction behavior of both the previously tested CERCOM SiC-B in partial pressures of oxygen compared to vacuum, especially when the slower tribo-oxidation kinetics and the surface-oxide-induced reduction in grain pull-out of the boron/carbon-pressed Hexoloy are taken into account. Even in the presence of the thickest lubricating film formed at the 3.4 Torr P 0 2 , the COF still did not become reduced below-0.2 (and the MAX.COF below 0.3). These values are an order-of-magnitude higher than those of the polished PCD. The same observation was made with the SiC-B previously. The wear rate of Hexoloy is only slightly (albeit consistently) less in oxygen than that of the SiC-B, with both in the 10'mW/N.m range (an order-of-magnitude greater than PCD). Considering the overall tribological behavior of both a-SiC materials, neither is able to serve better than PCD in MEMS moving mechanical assembly applications intended for extreme environments. 14. SUBJECT TERMS 15. NUMBER OF PAGES MEMS, poly-XTL ax-SiC, friction, wear, SEM tribometry, vacuum, oxygen partial pressures, high temperatures, SEM/AES/XPS analyses, dangling bonds 16. PRICE CODE re(de)construction, graphitization, gas-phase lubrication. 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF REPORT OF THIS PAGE

No abstract

No abstract

No abstract