Materials Research for Advanced Inertial Instrumentation. Task 2: Gas Bearing Material Development.
Abstract
Chemical vapor deposition (CVD) studies were continued with formation of additional boron coatings on beryllium. Problems encountered earlier with respect to coating thickness non-uniformity were corrected by installing a feed-through to the CVD chamber which permitted rotation of the samples during deposition. Questions pertaining gas cylinder selected for the diborane gas used during CVD, were successfully addressed through control of diborane gas concentration (by diluting it with Argon gas) and selection of an appropriate substrate temperature for deposition. Friction and wear tests performed on these recently formed coatings showed excellent wear resistance with very low friction coefficient values of the surfaces versus a diamond stylus serving as a pin. The performance against a sapphire pin, however, was quite poor with high measured values of the friction coefficient in agreement with observations reported earlier. These experiments indicated tht the deposition temperature was not particularly critical in determining coating quality. Additional activities included Auger Electron Spectroscopy (AES) characterization of the surfaces that were tested for wear, and initiation of procedures for fabricating parts for evaluation after assembling into an actual gyro gas bearing configuration. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1982
- Accession Number
- ADA130471
Entities
People
- Debanik Das
- K. Kumar
Organizations
- Charles Stark Draper Laboratory