热处理对TC19钛合金β晶粒尺寸和拉伸性能的影响

Effect of Heat Treatment on β Grain Size and Tensile Property of TC19 Titanium Alloy

以TC19钛合金棒材为研究对象,研究了该合金在β相区的晶粒长大特征和机制,并分析了其对拉伸性能的影响规律。结果表明,在975~1 005℃,TC19钛合金的β晶粒长大规律可用Beck方程描述,其在975、990、1 005℃的晶粒长大动力学指数分别为0.517、0.521、0.536。利用Arrhenius公式计算得到TC19钛合金β晶粒长大的表观激活能Q为226.9 kJ/mol。拉伸实验结果表明,TC19钛合金的室温强度对原始β晶粒尺寸不敏感,其断口形貌为典型的准解理断裂。

The grain growth behavior in the β phase field and its effects on the tensile properties were investigated in a TC19 titanium alloy forging billet. The experimental results show that the growth behavior of the β grain can be effectively described by the Beck equation, and the grain growth kinetics exponents are found to be 0.517, 0.521, and 0.536 at 975 ℃, 990 ℃, and 1 005 ℃, respectively. Moreover, the apparent activation energy Q for grain growth is about 226.9 kJ/mol based on the Arrhenius relation.The tensile performance shows that the size of the β grain has little influence on room temperature strength in this work, the typical quasi-cleavage fracture morphology is dominant.