Grain Refinement Mechanism of V-5Cr-5Ti Alloy Based on Equal Channel Angular Pressing

作者：Huang Shuke^*; Li Jingmin; Meng Yutang; Zhang Yonghao; Liu Jianhui; Li Changan

来源：Rare Metal Materials and Engineering, 2016, 45(9): 2313-2316.

• V-5Cr-5Ti alloy
• equal channel angular pressing
• grain refinement

The feasibility of equal channel angular pressing (ECAP) for treating V-5Cr-5Ti alloy was investigated. The effect of annealing treatment on the hardness and grain refinement mechanism of the alloy was analyzed. ECAP was performed using pressing dies and a universal material testing machine. The annealing was done in a vacuum heat treatment furnace. The hardness was tested using a Vickers hardness tester. The phase structure was identified using X-ray diffraction (XRD). The microstructure was observed using optical microscope (OM). The results indicate that the grain size of V-5Cr-5Ti alloy can be refined from 100 gm to 30 gm after two times ECAP and annealing above 950 degrees C. It is different from the traditional grain refinement mechanism of bcc alloy. The grains of V-5Cr-5Ti alloy are rotated on itself in ECAP process, and a lot of shearing glide bands are formed in coarse grains. With the annealing temperature increasing, fine grains are formed gradually at shearing glide bands and the initial grain boundaries are still clear. Finally, the fine grains are formed completely above 950 degrees C, and the initial grain boundaries become blurred gradually.

• 出版日期2016-9
• 单位中国工程物理研究院