机械合金化对Laves相TaCr_2固相合成的影响  

Effect of Mechanical Alloying on Synthesis of Laves Phase TaCr_2 by Solid-phase Thermal Reaction

作　　者：姚敬[1] 鲁世强[1,2] 肖璇[2] 

机构地区：[1]南京航空航天大学材料科学与技术学院,江苏南京210016 [2]南昌航空大学航空制造工程学院,江西南昌330063

出　　处：《矿冶工程》2017年第3期136-139,共4页Mining and Metallurgical Engineering

基　　金：国家自然科学基金(51161020);江西省自然科学基金(20114BAB216012)

摘　　要：对Cr-33.3%Ta(原子分数)混合粉末进行高能球磨,采用X射线衍射仪分析了机械合金化对Laves相TaCr_2固相合成反应的影响。结果表明,机械合金化过程对TaCr_2的固相合成反应产生显著活化效果,Cr-33.3%Ta混合粉球磨30 h后,再高温固相合成3 h时,使Laves相TaCr_2固相合成反应充分进行的温度门槛值为1 000℃,而未机械活化的原始样品的合成温度门槛值为1 350℃;在1 000℃×3 h高温合成时,使Laves相TaCr_2合成反应充分进行的机械合金化时间为25 h;球磨30 h的Cr-33.3%Ta混合粉在1 000℃合成时,固相合成反应充分进行的最短时间为1 h;为了避免或减少机械合金化粉末在发生Laves相TaCr_2固相合成反应之前发生非平衡过饱和固溶体的脱溶,应尽量采用到温进炉的方式。A blended powder of Cr-33.3%Ta（atomic fraction） was mechanically alloyed by high-energy ball milling and effect of mechanical alloying（MA） on the solid-phase synthesis reaction of Laves phase TaCr2 was investigated by using XRD. It is found that MA can lead to a remarkable mechanical activation for the synthesis reaction of Laves phase TaCr2.The blended powder of Cr-33. 3% Ta was subjected to a 30-h ball milling process before a 3-h high-temperature solid phase synthesis,resulting in the threshold temperature for a complete reaction of solid-phase synthesis of Laves phase TaCr2 reduced to 1 000 ℃,compared to the temperature of 1 350 ℃ for primary sample without MA process. It needs a25-h high-energy ball milling before a 3-h high-temperature synthesis reaction at 1 000 ℃ for a complete solid-phase synthesis reaction of Laves phase TaCr2. However,after a 30-h ball milling for Cr-33.3%Ta powder,a complete reaction of solid-phase synthesis at the temperature of 1 000 ℃ can be reduced to 1 h. Furthermore,in order to prevent the precipitation of non-equilibrium supersaturated solid solution for Laves phase TaCr2 before solid-phase synthesis reaction,the mechanically alloyed powder should be loaded into a vacuum sintering furnace as much as possible when it is heated to the required temperature.

关 键 词：LAVES相 TaCr2 机械合金化 固相反应 合成 

分 类 号：TG146[一般工业技术—材料科学与工程]