AI-10Sr合金焊接接头组织和性能分析

Study on the microstructure and mechanical properties of welding joint for Al-10Sr

分别采用TIG焊和火焰钎焊焊接了铝锶合金,并比较了焊接接头的显微组织和力学性能。结果表明,在铝锶合金的TIG焊焊缝中,均匀分布着Al4Sr、Al2Sr两相混合物针状组织;而在火焰钎焊的焊缝中,未出现典型的针状组织。由于TIG焊焊缝中针状相的弥散析出,引起Sr元素再分配,并强化焊缝基体,使得TIG焊焊缝的硬度远高于母材;TIG焊接接头的抗拉强度为78.44 MPa,拉伸断口显示母材中心有局部未焊透现象。采用火焰钎焊焊接铝锶合金时,能获得焊缝表面成形良好、无焊接缺陷的焊接接头,接头抗拉强度为72.07 MPa,达到TIG焊的抗拉强度水平。

The microstructure and mechanical properties of welded joints of AI-IOSr alloy by TIG and flame brazing welding process were investigated.The results indicate that therc is acicular constituent which is the mixture of Al4Sr and Al2Sr well-distributing in TIG welding seam,which can not be found in the flame brazing welded.Due to acieular phase precipitates and solid solubility of Sr in matrix increases,the hardness of the TIG weld is mt, ch higher than that of base metal,and the tensile strength of joints is 78.44 MPa, while incomplete penetration has been found in fracture＇s center：Flame brazing welding gets good weld shape without incomplete penetration,and the tensile strength is 72.07 MPa, equal to the tensile strength of TIG.