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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。
Al-strontium alloy was welded by TIG welding and flame brazing respectively. The microstructure and mechanical properties of welded joints were compared. The results show that in the TIG weld of Al-strontium alloy, the needle-like structure of Al4Sr and Al2Sr mixture is uniformly distributed. However, the typical needle-like structure does not appear in the flame brazing weld. Due to the dispersion of acicular phase in the TIG weld, the redistribution of Sr and the strengthening of the weld matrix resulted in the hardness of the TIG weld being much higher than that of the base metal. The tensile strength of the TIG welded joint was 78.44 MPa Broken mouth shows the base metal parent material is not penetrated partially. When using flame brazing to weld aluminum-strontium alloy, the welded joint with good weld surface formation and no welding defects can be obtained. The tensile strength of the joint is 72.07 MPa, which reaches the tensile strength of TIG welding.