WC-37mass%Fe合金の機械的性質に及ぼす炭素添加の影響 Effect of Carbon Addition on Mechanical Properties of WC-37mass%Fe Alloy
The effect of carbon addition on microstructure and mechanical properties of WC-37mass%Fe sintered alloys has been investigated. These alloys are expected to be used instead of WC-Co alloys as stress relief layer materials for the sinter-bonding method of cemented carbide and carbon steel. The amounts of mixed carbon powder in binder material (iron and carbon powder) of the WC-37mass%Fe alloy green compacts are 0, 0.77, 1.25 and 2.00 mass%. These compacts were sintered at various temperatures in the range from 1463 to 1583 K. The 0, 0.77, 1.25 and 2.00mass%C added alloy compacts showed complete densification at 1553, 1543, 1533 and 1513 K, respectively. These sintered alloys are basically composed of tungsten carbide grains and binder metal, and fine pearlite structure is observed in binder metal parts for all alloys except 2.00mass%C added alloy. In addition, (Fe, W)<SUB>6</SUB>C, that is, η phase particles of 10-100μm in diameter were formed in 0 and 0.77mass%C added alloys, and needle-like cementites of 100μm in length were formed in 2.00mass%C added alloy. The hardness was 74-76HRA independently of carbon content, but the maximum bending strength of 2.31 GPa was obtained for 1.25mass%C added alloy. The fracture of the other alloys may be caused by the existence of coarse η phase particles or needle-like cementite.
粉体および粉末冶金 49(3), 183-188, 2002-03-15
Japan Society of Powder and Powder Metallurgy