Accession Number : ADA130471

Title :   Materials Research for Advanced Inertial Instrumentation. Task 2: Gas Bearing Material Development.

Descriptive Note : Technical research rept. no. 5, 1 Oct 81-30 Sep 82,

Corporate Author : CHARLES STARK DRAPER LAB INC CAMBRIDGE MA

Personal Author(s) : Das,D ; Kumar,K

PDF Url : ADA130471

Report Date : Dec 1982

Pagination or Media Count : 89

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)

Descriptors :   *INERTIAL SYSTEMS, *BERYLLIUM, *GAS BEARINGS, *COMPOSITE MATERIALS, BORON, ION IMPLANTATION, VAPOR DEPOSITION, DIFFUSION, MATRIX MATERIALS, CERAMIC MATERIALS, ISOSTATIC PRESSING

Subject Categories : Laminates and Composite Materials
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE