摘要
以AZ31B变形镁合金为研究对象,采用GS-TFL-6kW高功率横流CO2激光器对其进行焊接,研究镁合金激光焊接的工艺特点。利用金相显微镜、扫描电镜、硬度仪、拉伸试验机测试焊接接头的微观组织和力学性能。结果表明,选择合理的焊接工艺参数,可以获得外观质量良好,热影响区不明显的焊接接头。焊缝狭窄,组织为细小等轴晶,焊缝区硬度高于母材硬度。部分焊缝内存在少许裂纹、氢气孔等缺陷;焊接过程中镁、锌蒸发较多,导致铝、锰等元素相对含量增加;扫描断口显示断裂方式为韧脆混合断裂,接头抗拉强度为175.2 N/mm2,为母材的83.6%。
The AZ31B magnesium alloy plates were welded by GS-TFL-6 kW high-power cross-current CO2 laser and the mierostructure and mechanical properties of welded joints were analyzed by optical microscope, scanning electron microscope, hardness tester and tensile ma- chine. The results show that a sound weld is formed with the proper welding parameters. The heat affected zone is not obvious. The welding seam is narrow, composed of fine equiaxed crys- tal. The hardness of the joint is higher than that of the base metal. There are a small number of pores, cracks and other defects in the welding seam. In the process of welding, magnesium and zinc evaporate more than aluminum and manganese, resulting in increasing of aluminum and manganese. Fracture scanning shows that the fracture surface is characterized by a ductile-brit- tle mixed pattern, consisting of both dimples and cleavages. The tensile strength of the joints is 175.2 N/mm^2 ,acconunting for 83.6% of the base metal strength.
出处
《轻合金加工技术》
CAS
北大核心
2015年第11期60-64,共5页
Light Alloy Fabrication Technology
基金
高等学校博士学科点专项科研基金(20121514120007)
内蒙古自治区高等学校科学研究项目(NJZY13107)
关键词
镁合金
激光焊接
组织
力学性能
magnesium alloy
laser welding
microstructure
mechanical properties
