High Hardness and High Toughness Powder

Abstract

In order to provide a projection material for shot peening, a raw material powder for a high-hardness powder metallurgy material having a superior hydrochloric acid resistance, a hard friction powder, a high hardness and high toughness alloy powder that can be used for hard particles for sintering and the like, the present invention provides a high hardness and high toughness alloy powder including in % by mass: a total of 25% or greater and 50% or less of one or two of Mo and W; 5% or greater and 15% or less of Cr; 0% or greater and 0.3% or less of Si; 0% or greater and 35% or less of Mn; 0% or greater and 20% or less of V; 0% or greater and 15% or less of Fe; and the balance including Co and inevitable impurities.

1 . An alloy powder, comprising in % by mass:
 a total of 25% or greater and 50% or less of one or two of Mo and W;   5% or greater and 15% or less of Cr;   0% or greater and 0.3% or less of Si;   0% or greater and 35% or less of Mn;   0% or greater and 20% or less of V;   0% or greater and 15% or less of Fe; and   the balance consisting of Co and inevitable impurities.   
     
     
         2 . The alloy powder according to  claim 1 , wherein the alloy powder comprises in % by mass, one or two or more selected from: greater than 0% and 35% or less of Mn; greater than 0% and 20% or less of V; and
 greater than 0% and 15% or less of Fe.   
     
     
         3 . The alloy powder according to  claim 1 , wherein the alloy powder after ageing treatment has a Vickers hardness of 500 HV or greater. 
     
     
         4 . The alloy powder according to  claim 1 , wherein the alloy powder has an age hardening width of 100 HV or greater, wherein the age hardening width is defined by the following formula:
 Vickers hardness of a sintered compact of the alloy powder—Vickers hardness of the alloy powder before ageing treatment.   
     
     
         5 . A projection material for shot peening, comprising the alloy powder according to  claim 1 . 
     
     
         6 . A powder metallurgical composition, comprising the alloy powder according to  claim 1 . 
     
     
         7 . A sintered compact obtained by sintering a molded article of the powder metallurgical composition according to  claim 6 . 
     
     
         8 . The sintered compact according to  claim 7 , wherein the sintered compact has a bending strength of 400 MPa or greater.