TC4钛合金表面电子束熔覆Ti40阻燃钛合金工艺研究

Process of Electron Beam Cladding Ti40 Burn Resistant Titanium Alloy on TC4 Titanium Alloy

目的在TC4表面熔覆一层Ti40阻燃钛合金,并研究熔覆试样的组织与力学性能。方法采用电子束在TC4钛合金表面熔覆一层Ti40阻燃钛合金。采用光学显微镜(OM)分析熔覆试样的显微组织,用显微硬度计分析熔覆试样的显微硬度,用电子万能拉伸试验机分析熔覆试样的力学性能。结果在选定的最佳工艺参数下,熔覆层与基材熔合良好,熔覆层为均匀分布的等轴β晶粒,表面及熔合区组织晶粒细化。添加椭圆形扫描波形能使气孔缺陷明显减少,表层更加均匀,组织更细小。扫描波形对熔覆层显微硬度的整体分布形态影响不明显,Ti40熔覆层在上表面及熔合区附近的显微硬度比熔覆层中部略高。室温下力学性能测试结果表明,加扫描时成形试样的抗拉强度为857.3MPa,相对于基材降低了些许,断裂伸长率达到了42.69%,比TC4钛合金基材提升了约70%。结论采用电子束在TC4表面熔覆Ti40阻燃钛合金,能够获得良好的熔覆层组织以及力学性能。

To clad a layer of Ti40 flame retardant titanium alloy on the surface of TC4 and study the microstructure and mechanical properties of the cladding samples.A layer of Ti40 flame retardant titanium alloy was deposited on the surface of TC4 titanium alloy through electron beam cladding.The microstructure of the cladding sample was analyzed with an optical microscope(OM).The microhardness of the cladding sample was analyzed with a microhardness tester.And the mechanical properties of the cladding sample were analyzed with an electronic universal tensile testing machine.The experimental results show that the cladding layer was well fused with the base material under the optimum process parameters.The cladding layer was uniformly distributed with equiaxedβgrains.The surface and the fused region were finer,but there was a hole defect in it.After adding the oval scanning waveform,the hole defects were significantly reduced.The surface was more uniform.The grains were smaller.The influence of the oval scanning waveform on the microhardness of the cladding layer was not obvious.The microhardness of the Ti40 cladding layer near the upper surface and the fusion zone was slightly higher than that of the cladding layer.The results of mechanics performance testing at room temperature show that the tensile strength of the specimen was 857.3 MPa which was decreased slightly compared to the base material.And the elongation was 42.69%,which was about 70%higher than that of the base material.Cladding Ti40 burn resistant titanium alloy on TC4 surface with electron beam could obtain good macrostructure and mechanical properties of cladding layer.