锰和镁元素含量对5A01高镁铝合金组织及性能的影响

Effects of Mn and Mg Contents on Microstructure and Properties of 5A01 High Magnesium Aluminum Alloy

采用铸锭冶金法制备了三种成分的5A01高镁铝合金,通过显微组织观察、室温拉伸试验、剥落腐蚀试验及阳极极化曲线测试等方法研究了在5A01铝合金成分范围内增加锰和镁含量对其组织及性能的影响。结果表明:将Al-6.13%Mg-0.48%Mn铝合金中镁含量提高0.5%后,合金中枝晶数量无明显变化,锰含量提高0.5%后,枝晶数量明显减少;锰或镁含量增加0.5%后,均可提高合金的强度,但增加锰含量对合金强度的提高幅度优于镁的;冷轧后经180℃退火2h,该铝合金发生了剥落腐蚀,镁含量提高0.5%后,合金的剥落腐蚀敏感性提高,腐蚀电位降低;增加相同含量的锰,合金剥落腐蚀敏感性降低,腐蚀电位升高。

Three alloys with high magnesium and aluminum were prepared by ingot metallurgy to study the effects of increase Mn and Mg contents on the microstrueture and properties of 5A01 aluminum alloy, which by means of microstructure observation, room temperature tensile test, exfoliation corrosion test and anodic polarization curve test. The results show that the amount of dendrite in the alloy had not obvious change when increase the Mg content in the A1-6. 13 %Mg-0. 48%Mn aluminum alloy by 0. 5%, while the amount of dendrite decreased significantly when increase the Mn content by 0. 5 %. With the increase the Mg or Mn content by 0. 5 %, the strength of the alloy was improved, while Mn had better effect. After cold roiled and annealed at l80℃ for 2 h, exfoliation corrosion occurred for the 5A01 A1 alloy. The exfoliation corrosion sensitivity increased and corrosion potential decreased after Mg content increased by 0.5 %. Mn content increased by 0.5 %, the exfoliation corrosion sensitivity decreased and the corrosion potential increased.