Cast material and method of manufacturing cast material

Abstract

A cast material comprising hard phase particles mainly composed of a boride and/or a carbide, and a binder phase including an alloy mainly composed of Co and/or Ni. The average particle size of the hard phase particles is 3 μm or less, the average value of the aspect ratios of the hard phase particles is 2.3 or less, the content of the hard phase particles having a major axis exceeding 5 μm is 3 particles or less per 2,450 μm 2 , and the contact ratio between the hard phase particles is 40% or less.

1 . A cast material comprising hard phase particles mainly composed of a boride and/or a carbide and a binder phase including an alloy mainly composed of Co and/or Ni, wherein
 the average particle size of the hard phase particles is 3 μm or less, the average value of the aspect ratios of the hard phase particles is 2.3 or less, the content of the hard phase particles having a major axis exceeding 5 μm is 3 particles or less per 2,450 μM 2 , and the contact ratio between hard phase particles is 40% or less.   
     
     
         2 . The cast material according to  claim 1 , wherein:
 the hard phase particles are the boride and/or the carbide comprising at least one of Ni, Co, Cr, Mo, Mn, Cu, W, Fe and Si, and B and/or C.   
     
     
         3 . The cast material according to  claim 1 , wherein:
 the binder phase is the alloy comprising at least one of Cr, Mo, Mn, Cu, W, Fe and Si, and Co and/or Ni.   
     
     
         4 . The cast material according to  claim 1 , wherein:
 the content of B in the cast material is 1 to 6 wt % and the content of C in the cast material is 0 to 2.5 wt %.   
     
     
         5 . The cast material according to  claim 1 , wherein:
 the hard phase particles comprise a composite boride represented by Mo 2 NiB 2  or Mo 2 (Ni,Cr)B 2 , and the binder phase comprises a Ni-based alloy.   
     
     
         6 . A method of manufacturing a cast material comprising hard phase particles mainly composed of a boride and/or a carbide, and a binder phase including an alloy mainly composed of Co and/or Ni, comprising:
 obtaining a fused mixture by fusing the raw materials, for forming the cast material in a state of being mixed with each other, and   cooling the fused mixture,   wherein the cooling of the fused mixture includes a process of continuously cooling the fused mixture, at a cooling rate of 100° C./min or more, in a temperature range from the cooling starting temperature to 400° C.   
     
     
         7 . The method of manufacturing a cast material according to  claim 6 , wherein:
 the cooling of the fused mixture is performed by pouring the fused mixture into a mold set at room temperature to 1100° C.