TC17钛合金中的偏析现象研究

观察生产的两种规格 T C17棒材，发现两种规格棒材的横截面上均存在明显亮斑，通过高倍分析、EDS检测对亮斑进行研究。结果表明：两种规格T C17钛合金棒材低倍观察到的亮斑在高倍下呈现为β斑；β斑的形成原因是Cr元素存在偏析现象造成的，Cr元素在偏析区域的含量明显高于基体，从而导致偏析区域相变点低于基体；偏析主要集中在铸锭的中心及头部；对于T C17钛合金要控制偏析，应尽量控制熔炼和后续的热加工和热处理过程。

Study on Segregation Phenomenon in TC17 Titanium Alloy

There are significant bright spots in cross section of both specifications of titanium alloy bar ,the bright spots were studied through high-power analysis and EDS detection .The results show that the bright spots in TC17 titanium alloy bar by low times observation appear as beta patch at high magnification ;which is caused by Cr element segregation phenomenon ,the content of Cr element in segregation area is much higher than that in matrix ,which leads to the transition point of segregation area is lower than that of matrix ;segregation mainly concentrates in the center and the head of ingot .For the control of segregation to TC17 titanium alloy ,we should try to control the melting and subsequent thermal processing and heat treatment process .