The Wear Resistance of Pure and Silicon-Alloyed Isotropic Carbons

Abstract

Comparative evaluations of the wear resistance of isotropic pyrolytic carbons deposited in fluidized beds (Pyrolite carbons) were carried out at room temperature in distilled water. The test procedure employed a polished, rotating disk bearing on a polished flat specimen. Couples of pure and silicon-alloyed Pyrolite carbons, glassy carbon, titanium, and Stellite 21 were studied. All combinations exhibited a time-independent volume wear rate. For a given disk the wear resistance of pure carbons increased with increasing density. A further reduction in wear rate was achieved by alloying the pyrolytic carbon with silicon. Under comparable conditions the wear resistance of glassy carbon was found to be inferior to that of either high-density, pure Pyrolite carbon or the alloyed Pyrolite carbons. Metal plates were worn by carbon at rates comparable to high-density pure and alloyed isotropic carbon plates. However, as disks bearing on carbon flats, metals caused high wear rates that decreased by increasing the carbon density or by alloying with silicon. The best couples were found to be

1. High-density, pure, isotropic pyrolytic carbon/high-density, pure, isotropic pyrolytic carbon.

2. High-density, pure, isotropic pyrolytic carbon/silicon-alloyed, isotropic pyrolytic carbon.

3. Titanium or Stellite 21/silicon-alloyed, isotropic pyrolytic carbon.