均匀化退火对Mg-9Al-1Zn-0.2Ni-0.1Mn合金组织和腐蚀性能的影响  

Effects of Homogenizing Annealing Treatment on Microstructure and Corrosion Properties of Mg-9Al-1Zn-0.2Ni-0.1Mn Alloy

作　　者：陈泽龙 刘楚明[1] 许诗源[1] 万迎春[1] CHEN Zelong;LIU Chuming;XU Shiyuan;WANG Yingchun(School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《热加工工艺》2020年第16期140-145,共6页Hot Working Technology

摘　　要：采用X射线衍射、扫描电镜背散射等测试手段研究了Mg-9Al-1Zn-0.2Ni-0.1Mn合金不同状态的相组成、显微组织和腐蚀形貌,采用失重法测量了不同状态合金的腐蚀速率,采用动电位极化扫描法和交流阻抗法研究了不同状态合金的电化学特性。结果表明:铸态合金主要包含α-Mg相和第二相β-Mg17Al12,连续分布的第二相对腐蚀速率具有削弱作用。经415℃、保温20 h的均匀化退火后,绝大部分第二相溶入α-Mg基体,相分布形态被破坏,均匀化合金腐蚀速率达到3.99 mg/(cm2·h),比铸态提升了21%。The phase compositions, microstructures and corrosion morphology of Mg-9Al-1Zn-0.2Ni-0.1Mn alloy were studied by means of X ray diffraction and SEM backscatter. The corrosion rate of different alloys was measured by weight loss method. Electrochemical characteristics of different state alloys were studied by potentiodynamic polarization scanning and AC impedance spectroscopy. The results show that the cast alloy consists of α-Mg and the second phase β-Mg17 Al12. The second relative corrosion rate of continuous distribution is weakened. Most of the second phase dissolved into α-Mg matrix after 415 ℃ and 20 h heat preservation homogenization annealing, most of the second phase are dissolved into the α-Mg matrix, resulting in the disruption of phase distribution. Therefore, the dissolution rate of the homogenized alloy reaches 3.99 mg/(cm2·h), which increased by 21% compared with that of the cast alloy.

关 键 词：均匀化退火 腐蚀性能 Mg-9Al-1Zn-0.2Ni-0.1Mn合金 

分 类 号：TG166.4[金属学及工艺—热处理] TG174.36[金属学及工艺—金属学]