5052铝合金搭接搅拌摩擦焊研究

Study on Friction Stir Lap Welding of 5052 Al Alloy

针对5052-H112铝合金,采用不同的焊接速度进行搅拌摩擦焊试验,并对焊接接头显微组织和硬度进行了分析。结果表明:母材区基体上呈现大量的第二相粒子,平行于轧制方向。焊核区组织晶粒非常细小,热机影响区大部分发生了弯曲变形,热影响区晶粒为典型受热长大的组织;随着焊接速度的提高,焊缝表面纹理逐渐变粗,接头焊核区面积、焊核区晶粒度和热输入量都随之减小。接头硬度呈现"W"型分布,在热影响区处硬度值最低,存在明显的软化。

Aiming at 5052-H112 aluminum alloy, using friction stir welding experiments under different speeds, and with the help of optical microscope （OM）, the microstructure and hardness of the weld joints were analyzed. The results indicate that the base metal matrix render is on a lot of second-phase particles, which are paralleling to the rolling direction. In weld nuclear zone, the grain is very small. In most heat engine affected-zone, the bending deformation occurs. The heat-affected zone of the grain is the typical heated growth microstructure. As the speeds increasing, the weld surface texture becomes coarser. Joints welded core area, grain size and the amount of heat input of welding core zone decrease as the speeds increasing. The joint hardness presents ＂W＂ type distribution, and hardness is minimum in the heat -affected zone, with a significant softening.