Fabrication of in situ Ti2AlN/TiAl Composites by Reaction Hot Pressing and Their Properties
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2014年第1期
论文作者：孙东立 SUN Tao WANG Qing HAN Xiuli GUO Qiang WU Gaohui
文章页码：126 - 130
摘 要：Ti2AlN/TiAl composites with different volume fractions of reinforcement were successfully fabricated by hot-pressing sintering method（reaction hot pressing） using Ti, Al and TiN powders as starting materials. The synthesis process includes four stages: first, the reactions between Al and Ti powers and between Al and TiN powders respectively occur and result in TiAl3 phase; secondly, Al powders in the sample are exhausted; the remaining Ti cores react with TiAl3 layer to form Ti-Al intermetallics; moreover, a few Ti2AlN particles precipitate from the TiAl3 phase; thirdly, Ti-Al intermetallics react with the remaining Ti cores to form Ti3Al and TiAl phases. TiAl phase and original TiN powers are in direct contact each other; finally, the residual TiN powers react with TiAl phase and result in a plenty of Ti2AlN phase. Compared with TiAl matrix, the hardness, elastic modulus and high-temperature compressive strength of Ti2AlN/TiAl composite are improved obviously and they are all enhanced with increasing the volume fraction of Ti2AlN phase.
孙东立，SUN Tao，WANG Qing，HAN Xiuli，GUO Qiang，WU Gaohui
School of Materials Science and Engineering,Harbin Institute of Technology
摘 要：Ti2AlN/TiAl composites with different volume fractions of reinforcement were successfully fabricated by hot-pressing sintering method（reaction hot pressing） using Ti, Al and TiN powders as starting materials. The synthesis process includes four stages: first, the reactions between Al and Ti powers and between Al and TiN powders respectively occur and result in TiAl3 phase; secondly, Al powders in the sample are exhausted; the remaining Ti cores react with TiAl3 layer to form Ti-Al intermetallics; moreover, a few Ti2AlN particles precipitate from the TiAl3 phase; thirdly, Ti-Al intermetallics react with the remaining Ti cores to form Ti3Al and TiAl phases. TiAl phase and original TiN powers are in direct contact each other; finally, the residual TiN powers react with TiAl phase and result in a plenty of Ti2AlN phase. Compared with TiAl matrix, the hardness, elastic modulus and high-temperature compressive strength of Ti2AlN/TiAl composite are improved obviously and they are all enhanced with increasing the volume fraction of Ti2AlN phase.
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