Microstructures of mechanically activated Ti-46at.%Al powders and spark plasma sintered ultrafine TiAl alloy
来源期刊：Rare Metals2007年第6期
论文作者：XIA Li), DING Hui), Ruan Xuefong), and REN Yaoyao) ) College of Power and Mechanical Engineering, Wuhan University, Wuhan , China ) School of Physicals, Wuhan University, Wuhan, , China
文章页码：572 - 577
摘 要：Powder of Ti-46at.%Al was synthesized through mechanical activation （MA） for different milling times, and the 16 h MAed powder was sintered by using a spark plasma sintering （SPS） process at different sintering temperatures. The XRD profiles showed that the MAed Ti-46at.%Al powder for 12, 16, and 20 h contained initial α-Ti and Al phases, and that the SPSed TiAl alloys contained the gamma TiAl and α2-Ti3Al phases. The TEM showed two different types of regions in the 16 h MAed Ti-46at.%Al powder. One type consisted of only Al with a grain size about 80 nm, and the other type a mixture of Al and Ti with a grain size of 30 nm. According to the optical micrographs of MA-SPSed samples, the alloys sintered at higher temperatures showed a coarser microstructure. In the case of the 1473 K sintering, typical duplex structures （（α2 + γ） lamella and γ phases） with interlamellar spacings of 50-400 nm and the grain size either less than 100 nm, or 1000 nm were observed.
XIA Li1), DING Hui1), Ruan Xuefong1), and REN Yaoyao2) 1) College of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China 2) School of Physicals, Wuhan University, Wuhan, 430072, China
摘 要：Powder of Ti-46at.%Al was synthesized through mechanical activation （MA） for different milling times, and the 16 h MAed powder was sintered by using a spark plasma sintering （SPS） process at different sintering temperatures. The XRD profiles showed that the MAed Ti-46at.%Al powder for 12, 16, and 20 h contained initial α-Ti and Al phases, and that the SPSed TiAl alloys contained the gamma TiAl and α2-Ti3Al phases. The TEM showed two different types of regions in the 16 h MAed Ti-46at.%Al powder. One type consisted of only Al with a grain size about 80 nm, and the other type a mixture of Al and Ti with a grain size of 30 nm. According to the optical micrographs of MA-SPSed samples, the alloys sintered at higher temperatures showed a coarser microstructure. In the case of the 1473 K sintering, typical duplex structures （（α2 + γ） lamella and γ phases） with interlamellar spacings of 50-400 nm and the grain size either less than 100 nm, or 1000 nm were observed.
关键词：
