Accession Number : AD0776454

Title :   Holographic Characterization of Ceramics. Part IV. (Measurement of Surface Roughness on Si3N4 Bearing Surfaces).

Descriptive Note : Final rept.,

Corporate Author : TRW SYSTEMS GROUP REDONDO BEACH CALIF

Personal Author(s) : Roszhart,T. V.

Report Date : 1973

Pagination or Media Count : 69

Abstract : A method for measuring the surface roughness of ceramic bearings was developed using coherent light techniques. The method is noncontacting and nondestructive and is applicable to cylindrical (and spherical) surface geometries. Surface roughnesses varying from 193 microinches to 9.46 microinches (A.A.) were measured in the longitudinal and circumferential directions on typical Si3N4 bearing specimens. This technique, referred to as Coherent Surface Analysis, determines surface roughness by analyzing the scattering of a laser beam from random surfaces. Since the laser beam can be scanned over the entire surface, it is possible to measure point to point variations in roughness. This feature was used to measure the change in surface roughness caused by rolling contact fatigue. (Author)

Descriptors :   *Silicon nitrides, *Ceramic materials, *Bearings, *Holography, *Nondestructive testing, *Surface roughness, Lasers, Coherent optical radiation, Quality control, Surface properties, Finishes, Wear

Subject Categories : Ceramics, Refractories and Glass
      Machinery and Tools
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE