TC6钛合金的超塑性变形研究

 通过高温拉伸力学实验研究了T C6 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%;③T C6 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。

Study on the Superplastic Deformation of the TC6 Alloy

The deformation behavio r of the TC6 alloy at hig h temperature has been investigated using tensile tests.By SEM technolog y, the fracture mechanism has been analyzed throug h the morphologies of the failure surface. Theex perimental r esults show that : ① t he increase of defo rmation temperature and the decrease of strain rate ar e propitious to the improvement of the deformation ability of the TC6 alloy; ② the optimal process par ameters ar e the combination of 950℃ and 0. 001s^{- 1}, and the larg est elongation ratio can reach 267%; ③ t he tough fracture is the mainmode during the fracture procedure of the TC6 alloy; ④the fr actur e begins from the inclusions, and with the increment of deformation and the decr ement of str ain rate, it presents the much more tough fracture character istic.