焊接速度对TC4钛合金激光焊接成形及组织的影响

Influence of welding speed on joint forming and organization of TC4 titanium alloy by laser welding

采用10 k W碟片激光器焊接3 mm厚的TC4钛合金,研究了焊接速度变化对焊接接头成形以及力学性能的影响。试验结果表明:在碟片激光深熔焊条件下,TC4钛合金焊缝具有近I形的截面形貌,随着焊接速度的提高,焊缝熔宽尺寸逐渐减小,当速度为3.9 m/min时,熔宽反而会变宽。焊缝组织由α′马氏体构成,随着焊接速度的提高,焊缝中α′的数量变化并没有明显变化。不同焊接速度下TC4钛合金焊接接头的室温平均抗拉强度为1 147 MPa,伸长率为10%,比母材的略低,拉伸试样均断在母材区域。

A butt welding experiments on 3 mm thick TC4 titanium specimen were conducted by using 10 k W trudisc laser. Studied the influence of the welding speed change on weld forming and mechanical properties. Experimental results showed that under the condition of deep penetration laser, trudisc laser welding of TC4 titaniumalloy weld had close "I" typical cross section morphology. With the increase of welding speed, the size of the weld width decreased,when the speed of 3.9 m/min, the weld width became widen instead. The weld seam was only composed of α′martensite. With the increase of welding speed, weld seam in the number of α′ martensite change was not obvious.The tensile strength of the laser welded joints was 1 147 MPa at room temperature, which was equal to that of the base metal. The elongation of the joint, however, was slightly lower than the base metal with a ductility of 10%. The welded joints of TC4 alloys ware all broken on area of the base metal.