Patent ID: 8733313

Claim:
An iron-based sintered alloy material for a valve seat comprising a first hard particle and a second hard particle dispersed in an iron-based sintered alloy matrix, wherein the first hard particle and the second hard particle have a same hardness with a Vickers Hardness in a range of 650HV0.1 to 1100HV0.1, wherein the first hard particle is different in an average particle diameter from the second hard particle, and wherein the iron-based sintered alloy material for a valve seat satisfies all of Conditions 1 to 4 below: Condition 1: the first hard particle has an average primary particle diameter of 5 to 20 μm; Condition 2: the second hard particle has an average primary particle diameter of 20 to 150 μm; Condition 3: in a mix of a plurality of first hard particles and a plurality of second hard particles, a particle size distribution curve has N peaks (N is an integer equal to or larger than 2) and when particle diameters corresponding to peak top positions are denoted as D T1 to D TN , a peak top particle diameter difference between at least one neighboring D Tn-1 and D Tn (|D Tn-1 −D Tn |: n is an integer equal to or larger than 2 and equal to or smaller than N) is in a range of 15 to 100 μm; and Condition 4: a total area ratio occupied by the mix in a texture of the iron-based sintered alloy material is 10 to 60% by area.