THE APPLICATION OF POROUS METAL BEARINGS Available to Purchase

POROUS metal bearings are produced by partial compaction of metal powders in precision tools of the desired shape followed by the sintering of the powder compact in a reducing atmosphere at a temperature of about 80% of the absolute melting point of the metal. The sintered compact is repressed to restore dimensional accuracy, to produce a high surface finish and, by work hardening, to increase the elasticity. The amount of porosity depends mainly upon the degree of compaction of the powder, and does not change greatly during the subsequent sintering and repressing operations, whereas the size of the pores depends upon the particle size of the powder and the subsequent processing. Finally the porosity is impregnated with lubricating oil.