固溶温度对Al-Cu-Mg-Mn合金组织及性能的影响

Influence of Solution Temperature on Microstructures and Properties of Al-Cu-Mg-Mn Alloy

通过扫描电子显微电镜（SEM）、光学显微镜（OM）、显微硬度计及电化学测试，研究了固溶温度对Al-Cu-Mg-Mn合金组织及性能的影响．结果表明，在455～535℃范围内，随着固溶温度的增加，合金中粗大的第二相逐渐固溶进基体组织中，强化固溶效果得到增强，硬度逐渐提高．然而，随着固溶温度进一步提高，引起了晶粒的长大，硬度逐渐地降低；475～515℃范围内，合金耐蚀性能好；而固溶处理的Al-Cu-Mg-Mn合金在质量分数为3．5％的NaCl中的腐蚀模式为点蚀，点蚀是由于基体与第二相颗粒间形成微电池回路引起的．

The effects of solution temperature on microstructure and properties of Al-Cu-Mg-Mn alloy were studied by using scanning electron microscope （SEM）, optical microscope （OM）, hardness test and electrochemical test. The results showed that the coarse secondary phases dissolved into the matrix gradually, and the effect of solid solubility and hardness increased with the increase of the solution temperature in the range of 455-535℃. However, when the solution temperature increased greatly, the grains grew larger and the number of secondary phases reduced, hence the hardness decreased gradually; corrosion property of the alloy was good within the range 455-535 ℃; under different solution temperature the corrosion mode of Al-Cu-Mg-Mn alloy after immersion 3.5%NaCl solution was pitting. The corrosion mechanism of pitting was contributed to galvanic corrosion between matrix phase and secondary phase particles.