轧制变形量及热处理对Al-1Li-0.05Sc合金的抗腐蚀性能的影响

Effects of Rolling Deformation Rate and Heat Treatment on Corrosion Resistance of Al-1Li-0.05Sc Alloy

研究了不同轧制变形量及时效工艺对Al-1Li-0.05Sc合金的抗腐蚀性能的影响。金相结果表明,Al-1Li-0.05Sc合金腐蚀特征为孔蚀,电化学测试结果与SEM结果表明70%形变量试样由于其回复产生的大角度晶界在大形变量下被轧碎成小角度晶界,其抗腐蚀性能理想。255℃峰值时效时,合金中析出大量第二相,虽然提高了合金的力学性能,但是降低了合金的抗腐蚀性能,530℃×24 h+285℃×1.5 h时效为合金的最佳热处理工艺,50%轧制变形下的合金经时效处理后,其硬度有较大提升且抗腐蚀性能达到最佳。

Effects of rolling deformation rate and aging process on corrosion resistance of Al-1Li-0.05Sc alloy were investigated.OM results indicate that the corrosion is characterized by pitting corrosion.The electrochemical perfor⁃mance tests and TEM results reveal that the 70%deformation are crushed into small angle grain boundary under severe deformation amounts due to the high angle grain boundary generated by recovery,achiving desirable corrosion resis⁃tance.After peak aging treatment at 255℃,a large amount of second phase is precipitated in the alloy,improving the mechanical properties and reducing the corrosion resistance instead.530℃×24 h+285℃×1.5 h aging is the optimal heat treatment,where the mechanical properties of the alloy are greatly improved,and optimal corrosion resistance is obtained after 50%rolling deformation.