磁场电流对固溶处理AZ91焊接接头组织和性能的影响

Effect of magnetic current on microstructure and properties of AZ91 magnesium alloy welded joint after solution treatment

对AZ91镁板进行钨极氩弧焊(TIG)过程中,外加纵向交流磁场,并在焊后进行固溶处理,对焊接接头固溶处理后的组织性能进行了分析。结果表明,经固溶处理后,焊缝中第二相基本消失,焊缝组织由大量的单相α-Mg构成。随着磁场电流的增加,焊缝区的晶粒尺寸先减小后增大,焊接接头的显微硬度、抗拉强度、塑性和耐电化学腐蚀性先增大后减小。当磁场电流为1.5 A时,晶粒尺寸最小,接头力学性能和耐蚀性最好。

AC longitudinal magnetic field was applied on welding AZ91 magnesium alloy plate with TIG,and the microstructure and properties of the welded joints were analyzed after solid solution treatment.The results show that after solution treatment,the microstructure of the welded zone is composed of α-Mg matrix only and the second phases disappear almost.With the increase of magnetic field current,grains of the welded joints decreases first and then increase,but micro-hardness,tensile strength,plasticity and the electrochemical corrosion resistance first increase and then decrease.When the magnetic field current is 1.5 A,the grain size of welded joints is the finest,and the mechanical properties and corrosion resistance are the best.