Accession Number : ADA318154

Title :   Ceramic Bearing Development. Vol. 1, Fatigue and Wear Behavior of NBD-200 Silicon Nitride Balls.

Descriptive Note : Interim rept. 1 Aug 92-1 Oct 94,

Corporate Author : NORTON ADVANCED CERAMICS EAST GRANBY CT

Personal Author(s) : Burrier, Harold I., Jr. ; Burk, Charles

PDF Url : ADA318154

Report Date : MAR 1995

Pagination or Media Count : 144

Abstract : These are the test results of the fatigue and wear performance of NBD-200, silicon nitride balls under conditions of rolling contact in ball bearings. Life testing was done under conditions of load and EHD film thickness equal to or more severe than those to be expected in turbine engine mainshaft applications. The actual temperatures and speeds of those applications were not simulated. No fatigue failures occurred in a sample of 556 'standard' NBD-200 balls within a test limit of five times the experimentally - determined L-10 life of the AISI 52100 steel balls. Ball failures did occur in a sample of balls identified by a Surface Acoustic Wave NDE technique as being flawed, but the correspondence between the estimated severity of the flaws and the specific ball failures was not good. A Thermal Proof Testing technique for eliminating balls with flaws may possibly have promoted failures of balls that otherwise would have performed satisfactorily. Wear tests, performed under moderate to severe boundary lubrication conditions showed no measurable, 'conventional' wear. The life - limiting factor in these hybrid bearings was microspalling of the AISI 52100 and M-50 steel races.

Descriptors :   *CERAMIC MATERIALS, *WEAR, *FATIGUE(MECHANICS), *SILICON NITRIDES, *BALL BEARINGS, TEST AND EVALUATION, THICKNESS, ROLL, FILMS, BOUNDARY LAYER, HYBRID SYSTEMS, TURBINES, SHAFTS(MACHINE ELEMENTS), LIFE TESTS, FAILURE(MECHANICS), FRICTION, LUBRICATION, SURFACE ACOUSTIC WAVES.

Subject Categories : Machinery and Tools
      Inorganic Chemistry
      Ceramics, Refractories and Glass
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE