增材制造工艺及热处理对Ti-6Al-4V合金组织和性能的影响

Effect of additive manufacturing process and heat treatment on microstructure and properties of Ti-6Al-4V alloy

Ti-6Al-4V(TC4)钛合金是一种使用较为广泛的α+β型两相钛合金,然而,由于增材制造钛合金存在微观缺陷,导致其机械性能低于锻造水平,通常需要进行后处理。本文综述增材制造过程中常见的工艺参数如能量输入功率、扫描策略等以及其他工艺参数如保护气种类、基板厚度、粉末粒度等因素对钛合金微观结构和综合性能的影响,并综合分析增材制造常见的后热处理方式对微观结构与力学性能影响,归纳了新型后热处理方式,如真空热处理、循环热处理等以及多种后处理与热处理综合使用的效果。对增材制造工艺参数的合理选择以及后热处理方式的应用是获得性能优良的钛合金构件的基础,将多种热处理方式综合使用,或将其他后处理方式与热处理综合使用是进一步提升增材制造钛合金构件性能的有效途径,建立一个增材制造工艺参数和后处理工艺统一选择标准则是增材制造领域未来发展的关键。

Ti-6Al-4V(TC4) titanium alloy is a kind of α+β type two-phase titanium alloy widely used.However,due to the microscopic defects in additive manufacturing titanium alloy,its mechanical properties are lower than the forging level,and posttreatment is usually required.Therefore,it is necessary to further study the additive manufacturing process and post-treatment of TC4 titanium alloy.In this paper,the microstructure and comprehensive properties of titanium alloy were analyzed by the changes of common process parameters such as energy input power and scanning strategy in the additive manufacturing process,and the influence of other process parameters such as protective gas type,substrate thickness,powder size and other factors in the additive manufacturing process was introduced.The influence of common heat treatment methods after additive manufacturing on its microstructure and mechanical properties was also comprehensively analyzed,and the influence of new post-heat treatment methods,such as vacuum heat treatment and cyclic heat treatment,as well as the influence of multiple post-treatment and comprehensive use of heat treatment were summarized.Generally speaking that the reasonable selection of additive manufacturing process parameters and the application of post-heat treatment method are the basis for obtaining titanium alloy components with excellent performance.The comprehensive use of various heat treatment methods or other post-treatment methods and heat treatment are the effective ways to further improve the performance of titanium alloy components in additive manufacturing.To establish a uniform selection standard for additive manufacturing process parameters and post-processing process is the key to the future development of additive manufacturing.