【摘要】 电弧增材制造过程中固有的高冷却速率和温度梯度使得沉积钛合金产生粗大的初生β柱状晶粒，降低合金的塑性和疲劳性能。采用原位合金化的方法引入高生长限制因子元素改变熔池凝固，促进柱状晶粒发生等轴化转变是提升沉积态钛合金性能有效的方法。总结了电弧增材制造中原位合金化方法，分析了非金属和金属合金化元素对电弧增材制造钛合金组织和性能的影响，以及合金化元素诱导柱状晶发生等轴化的转变机理，最后对电弧增材制造钛合金成分设计提出了展望。更多还原

【Abstract】 The intrinsic high cooling rate and temperature gradient during wire and arc additive manufacturing(WAAM) process can result in coarse primary β columnar grains in deposited titanium alloys, which deteriorates the plasticity and fatigue properties. In-situ alloying was employed to introduce the element with high growth limiting factor in order to alter solidification of molten pool and promote the equiaxed transformation of columnar grains, which is an effective method to improve the properties of deposited Ti alloys. The in-situ alloying methods in WAAM process were summarized, and influence of nonmetallic and metal-alloyed elements on microstructure and mechanical properties of WAAM Ti alloys, as well as the transformation mechanism of columnar grains were investigated. The composition design of titanium alloys for WAAM was prospected.更多还原