机械合金化法制备TiNi合金及其表征

Microstructure of titanium-nickel alloy by mechanical alloying

采用机械合金化技术,分别以Ti,Ni及Cu纯元素粉末制备Ti50Ni50合金及Ti50Ni45Cu5合金。利用X线衍射仪(XRD)分析球磨时间、球磨转速以及第3组元Cu的加入对粉末的组成、衍射峰强度和晶格常数变化率的影响,通过扫描电子显微镜(SEM)观察不同条件下粉末的形貌。研究结果表明:随着球磨时间的延长,Ti和Ni的衍射峰强度降低,峰逐渐宽化并向低角度发生偏移;球磨8 h后,获得最大的Ni的晶格常数变化率,并使得粉末粒径最大程度地降低;适当提高球磨转速有利于合金化的进行,400 r/min的球磨转速能够使得Ni最强峰的衍射强度最大限度地降低,粉末粒径降低幅度达65 nm;在Ti和Ni中加入第3组元Cu后,合金化程度略增强。

A procedure for producing equiatomic Ti Ni and Ti50Ni45Cu5 alloys from Ti, Ni and Cu powders by mechanical alloying was described, respectively. The structure, crystalline size, lattice deformation and morphology of powders were analyzed by means of XRD and SEM. The parameters of mechanical alloying process such as milling time, milling speed and the third element Cu were studied in order to understand their influences on powder characteristics. The results show that Ti and Ni X-ray peaks are wider and their intensity decreases with the increase of milling time. Higher crystal lattice constant variety of Ni can be achieved and the powder size decreases to the maximal degree after 8 h milling. It＇s beneficial to the alloying process to increase the milling speed and add the third element Cu. The strongest Ni X-ray peak intensity decreases greatly at 400 r/min milling speed, and crystalline size decreases by 65 nm.