激光沉积与热轧复合制造TC4钛合金组织性能的研究

Study on Microstructure and Properties of TC4 Titanium Alloy Fabri‐cated by Laser Additive Manufacturing and Hot Rolling

采用激光沉积与热轧复合制造钛合金零部件,可在有效提高原材料利用率的同时,提高整体零部件的生产效率。基于激光同轴送粉技术在TC4热轧态板材上沉积制造TC4钛合金零部件,通过体视显微镜、光学显微镜、扫描电子显微镜、维氏硬度测试仪以及万能试验机对TC4试件进行微观组织观察与力学性能分析。结果表明,复合制造的TC4试件中存在热轧板材区、结合区域以及沉积制造区域,其中热轧板材区与结合区域主要由等轴晶组成,沉积制造区域则由外延生长的柱状晶构成。结合区域的维氏硬度约为375 HV,略高于热轧板材区(340 HV)与沉积制造区(355 HV)。复合制造拉伸试件在垂直沉积方向的抗拉性能(1029 MPa)优于平行沉积方向(955 MPa),而平行沉积方向的延伸率(19.8%)优于垂直沉积方向(12.0%)。

Laser additive manufacturing and hot rolling composite manufacturing of titanium alloy parts can effectively im‐prove the utilization rate of raw materials and improve the production efficiency of the whole parts.In this paper,TC4 was deposited on TC4 hot-rolled sheet by laser coaxial powder feeding technology,and the microstructure and properties of TC4 samples were analyzed by stereo microscope,optical microscope,scanning electron microscope,Vickers hardness tester and universal testing machine.The results show that there are hot rolled plate region,bonding region and deposition manufactur‐ing region in the composite fabricated TC4 samples.The hot rolled plate region and bonding region are mainly composed of equiaxed grains,while the deposition manufacturing region is composed of epitaxial columnar grains.The Vickers hardness of bonded area is about 375 HV,which is slightly higher than that of hot rolled area(340 HV)and deposited area(355 HV).The tensile properties of composite fabricated specimens in vertical deposition direction(1029.0 MPa)are better than those in parallel deposition direction(955.0 MPa),and the elongation in parallel deposition direction(19.8%)is better than that in vertical deposition direction(12.0%).