中空挤压铝型材焊合位置组织和性能试验

Microstructure and Property Test of Welding Position of Hollow Extruded Aluminum Profile

以汽车用6005A中空挤压铝型材为研究对象,进行焊合位置组织和性能试验。基于不同挤压速度,借助晶粒度检验、显微布氏硬度检验、低倍宏观断口观察,分析中空挤压铝型材焊合位置组织和性能的变化规律。试验结果表明,在挤压模具和其它工艺相同的条件下,随着挤压速度的增大,中空挤压铝型材焊合位置的晶粒尺寸呈现先快速减小后增大的趋势。当挤压速度为20 mm/s时,晶粒最为细小且均匀,晶粒度级别为7。中空挤压铝型材焊合位置有较低的硬度,焊合区域的硬度随挤压速度的增大呈现先提高后降低的趋势,合金基体部分和焊合线处的硬度差则越来越小。若挤压速度过大或过小,则中空挤压铝型材焊合位置会出现焊合不良现象,合金性能降低。

Taking 6005A hollow extruded aluminum profile for automobile as the research object,the microstructure and property of the welding position were tested.Based on different extrusion speeds,the microparticle size test,micro-Brinell hardness test and low-power macroscopic fracture observation were used to analyze the changes of the microstructure and property of the welding position of hollow extruded aluminum profile.The test results show that under the same conditions of extrusion die and other processes,with the increase of extrusion speed,the grain size of the welding position of hollow extruded aluminum profile shows a trend of rapid decrease and then increase.When the extrusion speed is 20 mm/s,the grain is the finest and uniform,and the grain size level is 7.The welding position of hollow extruded aluminum profile has lower hardness,the hardness of the welding area shows a trend of first increasing and then decreasing with the increase of extrusion speed,and the hardness difference between the alloy matrix part and the welding line is getting smaller and smaller.If the extrusion speed is too large or too small,the welding position of the hollow extruded aluminum profile will have poor welding phenomenon,and the alloy performance will be reduced.