激光沉积修复TA15/TC17钛合金组织与力学性能

Microstructure and Mechanical Properties of Laser Deposition Repair of TA15/TC17 Titanium Alloy

针对TC17钛合金薄壁零部件边缘损伤修复需求,采用TA15钛合金粉末对TC17钛合金损伤试样进行激光沉积修复试验,通过优化工艺参数,获得了较小熔深、无缺陷的修复试样;研究了激光沉积修复试样的显微组织特征、室温拉伸性能及硬度分布。结果表明:TA15修复区组织为粗大的原始柱状β晶,晶粒内为α/β网篮组织,α片层取向随机;相对于TC17基体,热影响区α片层组织出现了细化现象,长宽比有所降低,但α片层宽度明显减小;修复试样室温抗拉强度达到TC17锻件的90.2%,比TA15锻件高10.6%,断后延伸率为4.3%,略低于TC17和TA15锻件;热影响区的显微硬度略高于基体和修复区,TA15修复区的显微硬度低于TC17基体的硬度,高于TA15锻件硬度。

Aiming at the need of edge damage repair of thin wall parts of TC17 titanium alloy,the laser deposition repair test of TC17 titanium alloy damage specimen was carried out by using TA15 titanium alloy powder.By optimizing the process parameters,the less penetration and no defect repairing specimen was obtained.The microstructure,tensile properties and hardness distribution of laser deposited specimens were studied.The results show that the microstructures of the repair zone of TA15 are coarse columnarβcrystals,α/βbasket structure in grains,αlamellar orientation is random,compared with the TC17 substrate,theαlamellar structure in the heat-affected zone appears to be refined,the aspect ratio is improved.The tensile strength of the repaired specimens at room temperature reached 90.2%of that of the TC17 forgings,which was 10.6%higher than that of the TA15 forgings,the elongation after break is 4.3%,slightly lower than that of TC17 and TA15 forgings.The microhardness of the heat-affected zone was slightly higher than that of the substrate and the repair zone of TA15,which was lower than that of the TC17 substrate and higher than that of the TA15 forging hardness.