TC4钛合金激光焊接接头金相试样的制备与显微组织分析

Metallographic Sample Preparation and Microstructure Analysis of TC4 Titanium Alloy Laser Welded Joints

利用5 kW光纤激光实现了6 mm厚的TC4钛合金板的连接。介绍了其金相试样的制作过程,并利用超景深光学显微镜分析焊缝显微组织,研究了焊速度对焊缝成形及显微组织的影响。结果表明:随着焊接速度的增加,熔深增加,焊接速度增加到0.018m/s时,未焊透。在焊缝中部及熔合线部位有气孔产生,并且不同位置的气孔大小不一;热影响区内发现少量针状马氏体α′,焊缝内全部为α′相,有魏氏组织形成。

5 kW fiber laser was used to weld TC4 titanium alloy with 6mm thickness, and the mctallographic sarnplc preparation process was introduced. Optical microscope was used to describe microstructure, and the effect of welding speed on weld formation and microstructure was studied. The results show that： with the increase of weld speed and penetration, when the welding speed increases to 0.018 m/s, there is lack of penetration. Fusion line porosity and weld central line porosity arc found, and pore sizes are different in different locations. A small amount of acicular martensite of phase is founded in HAZ, and the weld seam is only composed of α＇ martensite, which has widmanstatten structure.