摘要本试验是先通过不同的焊接工艺参数对2mm厚工业纯钛TA2进行激光焊接，观察焊道的宏观形貌以及分析焊接工艺参数对接头焊缝的熔深、熔宽和咬边的影响，从而确定出工业纯钛TA2最佳的激光焊接工艺参数。研究最佳焊接工艺参数下激光焊接工业纯钛TA2接头的微观组织，分析出焊接接头各部分的微观组织成分。通过拉伸测试和硬度测试，分析工业纯钛TA2激光焊接接头的力学性能。86599

试验结果表明：激光焊接工业纯钛TA2的激光功率为2250W,焊接速度为30mm/s时，焊道的表面呈银白色，焊缝条纹均匀，焊缝质量最佳；在焊接速度不变时，随着焊接功率的增加，接头焊缝的熔宽明显增大，熔深略有减小；在焊接功率不变时，随着焊接速度的增加，接头焊缝的熔宽变小，熔深基本不变；焊接的咬边缺陷与焊接的熔化量有关。对最佳焊接工艺参数下激光焊接工业纯钛TA2焊接接头力学性能分析，发现焊缝的硬度为 148-175HV，母材的硬度在110-125HV，焊缝的硬度高于母材，焊缝热影响区的范围为0。4mm。焊接接头的抗拉强度高于母材，断口出现在母材区，断口特征为微孔聚集体的等轴韧窝，接头平均延伸率为42。5%，高于母材的33%。

毕业论文关键词：工业纯钛TA2；纯激光焊接；焊接工艺参数；微观组织；力学性能

Abstract This test is by different welding process parameters on the first 2 mm thick of industrial pure titanium TA2 in laser welding, to observe the macro morphology of weld and welding technology parameters on joint weld penetration, weld width and bite edge effect, to determine the best of industrial pure titanium TA2 laser welding process parameters。 Research under the optimal welding process parameters of laser welding of industrial pure titanium TA2 joint microstructure, analysis of the welding joint microstructure composition of each part。 By tensile test and hardness test, analysis of industrial pure titanium TA2 laser welded joint mechanical properties。

The test results show that the laser welding of industrial pure titanium TA2 laser power is 2250 W, when the welding speed of 30 mm/s, the surface of the weld is silvery white, uniform weld stripes, weld quality best; When welding speed is constant, with the increase of the welding power, the weld joint weld width increase obviously, penetration decreases slightly; When welding power is constant, with the increase of welding speed, joint weld fusion width smaller, basic constant penetration; Welding bite edge defects associated with the fusion quality of welding。 The best welding process parameters of laser welding of industrial pure titanium TA2 welded joint mechanical property analysis, found that the hardness of the weld was 148-175 HV, the parent metal hardness in 110-125 HV, weld hardness is higher than the parent metal, weld heat affected zone is 0。4 mm。 The tensile strength of welded joint is higher than the parent metal, fracture appears in the parent metal zone, fracture characteristics of microporous aggregate toughening, such as shaft joint average elongation is 42。5%, higher than 33% of the parent metal。

Keywords: pure titanium TA2; pure laser welding; welding process parameters; microstructure; mechanical properties

目  录

第一章 绪论 1

1。1  课题研究的背景及意义 1

1。2  钛的国内外发展状况 2

1。3  工业纯钛TA2的基本特性及焊接特点 3

1。3。1、 工业纯钛的分类 3

1。3。2、 工业纯钛TA2的基本特性和焊接特点 3

1。3。3、 钛的焊缝质量与焊缝颜色的关系