Crを含有したMo_2NiB_2系硬質合金の特性および組織に及ぼすW添加量の影響 Effect of W Content on the Properties and Structure of Cr-containing Mo_2NiB_2 Base Hard Alloys
The properties of a complex (Mo, Ni) boride influenced by additions of W were investigated in Mo-Ni-Cr-W-B sintered alloys where the boride has the tetragonal crystal structure due to solid solutioning of Cr. Additions of W lead to partition of W primarily into the complex boride, resulting in a stoichiometric change of the tetragonal boride from Mo<SUB>2</SUB>(Ni, Cr)B<SUB>2</SUB> to (Mo, W)<SUB>5-x</SUB>(Ni, Cr)<SUB>x</SUB>B<SUB>3</SUB> around 10mass%W. The alloys having the tetragonal Mo<SUB>2</SUB>(Ni, Cr)B<SUB>2</SUB> boride with W in the boride maintained high levels of transverse-rupture strength(TRS) and hardness due to small particle size of the boride up to 5mass%W. The stoichiometric change of the boride by additions of W caused increase in hardness and decrease in TRS due to increased volume fractions of the boride at the given boron content.
粉体および粉末冶金 43(4), 498-503, 1996-04-15
Japan Society of Powder and Powder Metallurgy