激光粉末床熔融成形Ti6Al4V/AlSi10Mg合金电子束焊接工艺研究

Electron Beam Welding Process of Ti6Al4V/AlSi10Mg Alloy by Laser Powder Bed Fusion

针对激光粉末床熔融成形的Ti6Al4V合金和AlSi10Mg合金进行电子束对接试验,对比分析不同侧偏束条件下焊接接头的组织和性能。结果表明:钛侧偏束(-0.6 mm)相较于铝侧偏束(+0.6 mm)所获接头的成形更稳定、美观。铝侧偏束时,接头表面出现了大量的气孔及裂纹,接头内部也存在大量的气孔,主要聚集于铝侧熔合线上;钛侧偏束时,接头焊接缺陷的数量明显减少。两种工艺条件下的界面层均形成了一定数量的金属间化合物,铝侧偏束时以TiAl为主,钛侧偏束时形成了TiAl3、TiAl_(2)、Ti_(3)Al和TiAl等多种金属间化合物。铝侧偏束接头抗拉强度最高为81 MPa,钛侧偏束接头抗拉强度最高可达到128 MPa。两种接头均失效于反应界面层处,呈现出脆性断裂的特征。

A comparative analysis of the microstructure and properties of laser powder bed fusion Ti6Al4V alloy and AlSi10Mg alloy welding joints was conducted through electron beam butt joint tests,under a range of divergent beam configu‐rations.The results showed that the joint formed by titanium side offset beam(-0.6 mm)was more stable and aesthetically pleasing compared to the joint formed by aluminum side offset beam(+0.6 mm).When using aluminum side offset beam,a large number of pores and cracks appeared on the surface of the joint,and there were also many pores inside the joint,mainly concentrated on the aluminum fusion line.When using titanium side offset beam,the number of welding defects in the joint significantly reduced.A certain amount of intermetallic compounds was formed in the interface layer under both process con‐ditions,with TiAl being the main compound formed when using aluminum side offset beam,and TiAl_(3),TiAl_(2),Ti_(3)Al,and TiAl being formed when using titanium side offset beam.The tensile strength of the joint formed with aluminum side offset beam was highest at 81 MPa,while the joint formed with titanium side offset beam could reach a maximum tensile strength of 128 MPa.Both joints failed at the reaction interface layer,exhibiting brittle fracture characteristics.