铝合金,特别是Al-Cu合金钨极氩弧焊时、在多层焊或补焊的近缝区金属中、常常有晶界变宽、三角晶界及孔洞等现象,它与热处理时的过烧组织有某些相似之处,因此人们曾判定为“过烧”或“焊接过烧”。 本文从金属学的概念出发,结合焊接冶金学的特点,对上述问题进行了对比性试验及分析工作,从中发现晶界变宽及三角晶界等组织可通过焊后热处理给予消除,并使其机械性能显著提高。经金相及微观断口的电子显微镜分析后认为,该区金属在焊接过程中只产生了晶界熔化,但无氧化迹象,其性质应不属过烧,只是晶界液化,因而建议将这种组织形态称为晶界液化为宜。 Aluminum alloy, especially the Al-Cu alloy TIG welding, in the multi-layer welding or repair near seam area metal, often grain boundary broadening, triangular grain boundaries and holes and other phenomena, which is the heat treatment Over-burning tissue has some similarities, so people have been judged as “over-burning” or “welding over-burning.” Based on the concept of metallurgy and the characteristics of welding metallurgy, this paper conducts a comparative experiment and analysis of the above problems, from which it can be found that the grain boundary broadening and the triangular grain boundaries can be eliminated by post-weld heat treatment, Significantly improved mechanical properties. Metallographic and microscopic fracture analysis of the electron microscopy that the metal in the area during the welding process only produced a grain boundary melting, but no signs of oxidation, its nature should not over-burning, but the grain boundary liquefaction, it is recommended that this Organizational form called grain boundary liquefaction is appropriate.