Nb_2Al組成MA粉末のパルス通電加圧焼結 Pulse Current Pressure Sintering of Nb_2Al Alloy Powder Prepared by Mechanical Alloying
The alloy powder of 2Nb/Al composition was prepared by mechanical alloying. The alloy powder became homogeneous and showed an amorphous-like pattern in X-ray diffraction after milling with a small amount of additives for 396ks. This mechanically alloyed powder kept the amorphous phase even after heating up to 973K for 600s, and was changed to Nb<SUB>2</SUB>Al phase by heating over the temperature of 1073K. The compact of this powder sintered at 973K for 300<SUB>s</SUB> by pulse current pressure sintering (PCPS) was not consolidated, although the amorphous structure was kept even after heating. On the other hand, the compact sintered at 1673K by PCPS method consisted of mainly Nb<SUB>2</SUB>Al phase and a small amount of uncertain phase. The density for the compacts sintered at 1673K was 7.16 × 10<SUP>3</SUP> kg/m<SUP>3</SUP>, which is about 5% higher than that for Nb<SUB>2</SUB>Al. Vickers hardness was 1000-1100, which is 15 to 30 % higher than that of Nb<SUB>2</SUB>Al (850-870). It can be speculated that these results are attributed to the finely dispersed particles containing Fe, which came from the container and/or balls for the mechanical alloying.
粉体および粉末冶金 44(12), 1115-1120, 1997-12-15
Japan Society of Powder and Powder Metallurgy