【摘要】 采用搅拌摩擦焊方法对2219-T6铝合金进行焊接,对焊接接头的宏观形貌、显微组织、拉伸强度、显微硬度进行了分析。结果表明,焊核区组织为细小的晶粒,热机影响区组织为弯曲变形的晶粒,热影响区组织出现了明显粗化。接头室温拉伸强度可以达到母材的75%左右,接头强度低于母材的原因主要归结为金属的塑性损伤、缺陷的产生和热影响区的软化。通过固溶及时效方法并兼顾再结晶过程的热处理工艺可以回复接头塑性、消除软化,达到改善接头性能的目的。更多还原

【Abstract】 Microstructure and mechanical properties of 2219-T6 aluminum alloy plate welded joints prepared by friction stir welding were investigated. The results show that the microstructure of the joint consists of refined grains in the weld nugget zone( NZ),deformed grains in the thermal-mechanically affected zone( TMAZ) and coarse grains in the heat affected zone( HAZ),respectively. Tensile tests show that the tensile strength of the joint can reach 75% of that of the base metal( BM). The decrease of the joint strength is due to the plastic damage of the base metal,the softening of the heat affected zone and the defects generated in the nugget zone. The mechanical properties of the welded joint can be improved by the post weld heat treatment( PWHT) of solid solution and artificial aging heat treatment.更多还原