TC6钛合金的超塑性变形研究

Study on the Superplastic Deformation of the TC6 Alloy

通过高温拉伸力学实验研究了TC6钛合金在高温下的流动特性,并利用扫描电镜观察了拉伸断口形貌,分析了该合金的拉伸断裂机制。实验结果表明:①变形温度的升高和应变速率的降低,有利于提高TC6钛合金的塑性变形能力;②TC6钛合金的最佳超塑性变形工艺参数为950℃,0.001s-1,最大延伸率为267%;③TC6钛合金在拉伸断裂时以韧性断裂为主,但在不同的变形温度和变形速率下伴随着不同程度的脆性断裂;④拉伸断裂从夹杂物或第二相粒子开始,且随着变形温度的升高和应变速率的降低,解理断口的比例减小,韧性断裂特征变得明显。

The deformation behavior of the TC6 alloy at high temperature has been investigated using tensile tests. By SEM technology, the fracture mechanism has been analyzed through the morphologies of the failure surface. The experimental results show that: (1)the increase of deformation temperature and the decrease of strain rate are propitious to the improvement of the deformation ability of the TC6 alloy; (2) the optimal process parameters are the combination of 950°C and 0.001 s-1, and the largest elongation ratio can reach 267%; (3) the tough fracture is the main mode during the fracture procedure of the TC6 alloy; (4) the fracture begins from the inclusions, and with the increment of deformation temperature and the decrement of strain rate, the much more tough fracture characteristic becomes more obvious.