Abrasion resistant valve seat made of sintered alloy for internal combustion engines

摘要

The invention is directed to an iron series sintered alloy superior in abrasion resistance, preferably usable for slipping parts such as valve seats used in internal combustion engines, vanes in compressors and so forth. The sintered alloy is of base matrix of a mixed structure comprising the primary phase of in area ratio 30 DIFFERENCE 95% mainly of Fe having a hardness of 400 Hv or above with precipitated fine carbide of 10 mu m or smaller, and the secondary phase of in area ratio 5 DIFFERENCE 70% softer than said primary phase, consisted of pure iron or carbon steel or low alloy steel. This base matrix will include in area ratio 1 DIFFERENCE 20% infiltrated or previously added Cu phase or Cu alloy phase, or will include dispersed therein in area ratio 1 DIFFERENCE 20% hard particles having average diameter of 20 DIFFERENCE 100 mu m and a hardnessof 700 DIFFERENCE 1500 Hv such as Fe-Mo paricles, Cr-Mo-Co intermetallic compound particles, C-Cr-W-Co particles, etc.