| 摘要 |
An internal combustion engine tappet comprising a sintered powdered metal wear resistant composition having a matrix formed from iron powder, carbon in the range of 0.50-1.0% by weight, and a ferroalloy powder with a mesh size of +50-325 acting as a nucleus for diffusion of the alloying metal into the surrounding iron particles. The alloying metal in the composition is in the range of 1-10% by weight and is selected from the group consisting of chromium, titanium, boron, vanadium, columbium, molybdenum, tantalum and tungsten. The iron, carbon and ferroalloy are briquetted at a pressure of 40-60 tons/sq.in. and sintered, in solid phase, at a temperature of 2000 DEG -2100 DEG F. in a reducing atmosphere. The resulting product is heterogeneous and has hard ferroalloy nuclei and interconnected porosity with a density at the tappet wear surface of approximately 6.8-7.0 gm/cc.
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