| 摘要 |
PURPOSE:To provide a sintered alloy having improved heat resistance and wear resistance, by uniformly dispersing specific ratios of hard grains formed with a metallic phase such as Ni, Co and Cu on the surface layer and surrounding parts of the grains into an iron alloyed matrix contg. specific ratios of C, Cr and CaF2. CONSTITUTION:The hard grains formed with any metallic phase among Ni, Co and Cu on the surface and surrounding parts of the grains by plating, etc., are dispersed into the iron alloy matrix consisting of, by weight, 10-20% Cr, 1.5-3.5% C, 0.5-3% CaF2 and the balance Fe at the total ratio of 5-20% to form the sintered alloy. The hard grains having <=149mum grain size and 800-2,000 Vickers hardness are preferably used. One ore more kinds among 1-5% Mo, Nb, W and V are furthermore incorporated into the iron alloyed matrix at need. Since said high Cr sintered alloy has the excellent heat resistance and wear resistance, it is usable as the parts material for a valve seat of an internal combustion engine, etc.
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