采用X-ray衍射分析了Ti-48at%Al混合粉末在高能球磨过程中的物相演变,用Miedema理论模型计算有序Ti/Al金属间化合物和非晶态的形成自由能。结果表明,Ti和Al元素粉末在机械合金化过程中的物相演变为:Ti+Al→无序fcc Ti(Al)固溶体、Ti Al、Ti Al3、Ti3Al→Ti Al3、Ti3Al→非晶,球磨3 h后出现了无序fcc Ti(Al)固溶体、Ti Al、Ti Al3和Ti3Al,高能球磨9 h后转化为无序非晶。经Miedema理论模型计算出各物相间在T=300 K时的自由能差,从热力学理论上证实了高能球磨Ti-48at%Al合金化过程的物相演变规律。
The elemental powder with nominal composition Ti-48at%Al was mechanically alloyed by high-energy ball milling for 9h. The phase evolution in the powder was characterized by X-ray diffraction. According to miedema theoretical model , the free energies of Ti/Al intermetallic compounds and amorphous alloy were calculated. The results show that, the milling process can be described by: Ti+Al→fcc Ti (Al),TiAl,TiAl3,Ti3Al→TiAl3,Ti3Al→amorphous. After milling for 3 h, Fcc Ti (AI) solid solution, TiAl, TiAl3 and Ti3Al are found. After ball milling for 9 h, Ti-48 at % Al amorphous alloy is produced. The free energy difference of Ti/Al is calculated by using Miedema theoretical model when T=300K. The X-ray diffraction analysis results are confirmed by thermo-dynamics theory.