Patent ID: 7273508

Claim:
An iron-based sintered alloy material for a valve seat, comprising: a base matrix phase; first hard particles; and second hard particles, wherein the first hard particles and the second hard particles have different hardness and are dispersed in the base matrix phase, the first hard particles are composed of a cobalt-based intermetallic compound and have a size of 10 to 150 μm and a hardness of 500HV0.1 or more and less than 800HV0.1, the second hard particles are composed of a cobalt-based intermetallic compound and have a size of 10 to 150 μm and a hardness of 800HV0.1 or more and less than 1100HV0.1, the first hard particles occupy 10% to 20% by area, the second hard particles occupy 15% to 35% by area, and the first hard particles and the second hard particles occupy 25% to 55% by area in total.