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将0.075mm的Ti,Cu,Ni,Sn4种金属粉按合金成分为Ti50Cu23Ni20Sn7进行配比,并在行星式球磨机中进行机械合金化(MA)球磨。试验中的球磨机转速为300r/m,球料比为10:1。XRD和DSC分析结果表明,经过30h球磨之后,金属粉末已经全部合金化,并且为非晶态结构。继续进行球磨只能减小粉末颗粒尺寸,却会引入更多的杂质,所以30h是制备Ti50Cu23Ni20Sn7非晶合金粉末最为合适的时间。SEM下观察发现,经机械合金化所获得的非晶粉为层状团聚结构。将所制备的非晶合金粉装入碳化钨模具中,并在放电等离子烧结(SPS)设备中进行快速烧结。其烧结的温度分别为480、490、500和510℃,烧结压力为500MPa,保温时间为1min。从XRD和DSC分析结果可以看出,烧结后的合金基体为非晶结构,并伴有少量晶化相。烧结件放在光学显微镜下观察可以看到少许缩孔和疏松等烧结缺陷。将温度为490℃下烧结的试件破碎,并将断口在SEM下观察可以发现,试件断裂方式为层状脆性断裂。试验结果表明采用机械合金化和放电等离子烧结技术可以成功制备出Ti基大块金属玻璃。
The 0.075mm Ti, Cu, Ni, Sn 4 kinds of metal powder alloy composition Ti50Cu23Ni20Sn7 ratio, and in a planetary ball mill mechanical alloying (MA) ball milling. In the experiment, the speed of ball mill was 300r / m and the ratio of ball to material was 10: 1. XRD and DSC analysis showed that after 30h ball milling, the metal powders were all alloyed and amorphous. Continue to ball milling only reduce the size of the powder particles, but will introduce more impurities, so 30h is the most suitable time for the preparation of Ti50Cu23Ni20Sn7 amorphous alloy powder. SEM observation revealed that the amorphous powder obtained by mechanical alloying was a layered agglomeration structure. The prepared amorphous alloy powder was charged into a tungsten carbide mold and subjected to rapid sintering in a discharge plasma sintering (SPS) apparatus. The sintering temperature was 480,490,500 and 510 ℃, sintering pressure of 500MPa, holding time of 1min. From the results of XRD and DSC analysis, it can be seen that the sintered alloy matrix has an amorphous structure with a small amount of crystallization phase. Sintered pieces placed under an optical microscope can be seen a little shrinkage and porosity and other sintering defects. The specimen sintered at 490 ℃ was broken, and the fracture was observed under the SEM. It can be found that the fracture mode of the specimen is layered brittle fracture. The experimental results show that Ti-based bulk metallic glass can be successfully prepared by mechanical alloying and spark plasma sintering.