窒素ショックMAとパルス通電加圧焼結により合成したTiAl-TiB_2複合材料の特性に及ぼす窒素の影響 Effect of Nitrogen on Properties of TiAl-TiB_2 Composite Material Synthesized by Nitrogen Shock Mechanical Alloying and Spark Plasma Activated Sintering
The authors formerly found out that intercurrent introduction of nitrogen gas into the milling atmosphere during mechanical alloying of Ti-Al powder mixture promotes the synthesis of alloy powder and named this process "nitrogen shock mechanical alloying". It was confirmed by x-ray diffraction analysis that nitride, Ti<SUB>2</SUB>AIN was formed in sintered bodies of the alloy powder synthesized by the nitrogen shock MA. It is expected that TiAl matrix can be strengthened by the nitride, if the nitride precipitates in the form of fine particles dispersed in the matrix.<BR>In this study, the nitrogen shock MA was applied to a mixture of Ti, Al and B powders to make a Ti-Al-B alloy powder and the alloy powder was consolidated by spark plasma activated sintering, in order to investigate effects of nitrogen on the microstructure and properties of sintered bodies. Boron was added in expectation of the formation of fine TiB<SUB>2</SUB> particles which strengthen the matrix as well as the nitride. As a result, it was found that nitrogen taken in the alloy powder enhances amorphization of the powder. It was also found that the nitride increases hardness and Young's modulus of the sintered bodies. However, the nitride formed excessively made the microstructure of the sintered bodies uneven.
粉体および粉末冶金 44(6), 542-546, 1997-06-15
Japan Society of Powder and Powder Metallurgy