Beta heat treatment of laser melting deposited high strength near beta titanium alloy
Beta heat treatment of laser melting deposited high strength near beta titanium alloy
复制标题
激光熔化沉积高强度近β钛合金的β热处理
DOI：
10.1016/j.msea.2016.07.027
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发表时间：
2016
期刊：
影响因子：
6.4
通讯作者：
Ma Shuyuan
中科院分区：
文献类型：
--
作者：
Liu Changmeng;Yu Lu;Zhang Ali;Tian Xiangjun;Liu Dong;Ma Shuyuan
为了改善β钛合金附近激光熔凝沉积的Ti-5Al-5Mo-5V-1Cr-1Fe高强度合金的力学性能，采用了传统热处理和新设计的β热处理。研究了相应的显微组织和拉伸性能。结果表明，传统的热处理样品由连续的线性晶界(α(α、LGB)组成。它的形成与激光熔化沉积过程中的逐层热循环处理有关。裂纹优先沿α晶界萌生和扩展，导致沿晶断裂，塑性较低。相反，贝塔热处理导致形成人字形魏氏晶界(α(αwgb)。αWGB有效地抑制了裂纹沿晶界的扩展，导致了以穿晶断裂为主的断裂，改善了塑性。
To improve the mechanical properties of laser melting deposited Ti-5Al-5Mo-5V-1Cr-1Fe high strength near β titanium alloy, the traditional heat treatment and new designed beta heat treatment are applied in this study. The corresponding microstructures and tensile properties are investigated. It is found that the traditional heat treated samples consist of continuous linear grain boundary α (αLGB). Its formation is found to be associated with the layer by layer thermal cycling treatment in laser melting deposition process. The cracks preferentially initiate and propagate along αLGB, leading to intercrystalline fracture and low ductility. In contrast, beta heat treatment leads to the formation of herringbone Widmanstätten grain boundary α (αWGB). The αWGBeffectively inhibits the crack propagation along grain boundary, resulting in the predominantly transcrystalline fracture and improved ductility.