Mechanical alloying and subsequent annealing effects on evolution of microstructure and morphology of TiH_2-Ni powders

机械合金化及热处理对TiH_2-Ni粉末结构和形貌的影响(英文)

Mechanical alloying and subsequent annealing treatment were carried out to investigate the evolution of the microstructure and morphology of the TiH2-Ni system. The Ni（Ti） solid solution was formed in the initial milling process. When the milling time was 60 h, the alloy with uniform elemental distribution showed an amorphous structure containing a small amount of TiH2 nanocrystalline phase. The annealing treatment at 693 K contributed to a completion of amorphization for the alloy milled for 60 h. For the treatment at 1 073 K, a crystallization reaction for the amorphous phase occurred, leading to the formation of Ti2Ni, TiNi, and TiNi3 compounds by a short time treatment. Moreover, a separation of Ni-rich phases from the matrix and a phase transition among these three compounds occur by a long time treatment.

研究机械合金化及热处理对TiH2-Ni粉末的结构和形貌的影响。在初始球磨阶段,Ni(Ti)固溶体形成。当球磨至60h时,非晶结构的TiH2-Ni粉末形成,粉末中还包含少量的纳米晶TiH2相,粉末内元素分布均匀。球磨60h的粉末经693K热处理,发生了非晶化反应;经1073K短时间热处理后,非晶相结晶,形成Ti2Ni、TiNi和TiNi3相;在相同热处理温度下进一步延长热处理时间可使富镍相析出以及在3种Ti-Ni相之间发生相转变。