メカニカルアロイングを用いた微細TiC分散合金の作製 Preparation of fine TiC dispersed alloy by mechanical alloying
The formation of ultra fine TiC dispersed alloy by mechanical alloying (MA) and spark plasma sintering (SPS) has been investigated. The composition of Ti<SUB>x</SUB>C<SUB>100-x</SUB> (x=50-80)-20mass%Ni(called cermet) and that of Ti<SUB>50</SUB>Ni<SUB>x</SUB> C<SUB>50-x</SUB> (x=20-45) (called NiTi alloy) alloy powder have been synthesized by MA of three kinds of elemental powders. During MA, TiC-Ni consolidation was formed in the vessel for the composition of less than 65at.%Ti mixture. In the case of cermet, after MA, for the composition of more than 70at.% Ti mixture, C and Ni powders were added to MA powder in order to make the total composition of Ti<SUB>50</SUB>C<SUB>50</SUB>-20mass%Ni cermet. The powder mixture of cermet and NiTi alloy was consolidated by SPS method at 1073K. The size of sintered body was φ15×3mm. This sintered body consisted of TiC, Ni, and Ni-Ti alloy. It was found that the ultra fine TiC (<1000nm) had been formed during SPS process by using Ti<SUB>75</SUB>C<SUB>25</SUB>-20mass%Ni+C+Ni powder. This ultra fine TiC was dispersed homogeneously in the cermet. In the case of NiTi alloy, the fine TiC was not observed in the sintered sample. And the sample of Ti<SUB>50</SUB>Ni<SUB>x</SUB>C<SUB>50-x</SUB> alloy was very brittle.
粉体および粉末冶金 45(4), 341-345, 1998-04-15
Japan Society of Powder and Powder Metallurgy