退火处理对AZ31镁合金表面Ni-Mo-P镀层组织与耐腐蚀性能的影响  

Effect of Annealing Treatment on the Microstructure and Corrosion Resistance of Ni-Mo-P Coating on the Surface of AZ31 Magnesium Alloy

作　　者：张锋刚[1] ZHANG Feng-gang(School of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, China)

机构地区：[1]陕西理工大学材料科学与工程学院

出　　处：《材料保护》2019年第4期78-84,共7页Materials Protection

基　　金：陕西省自然科学基础研究计划项目(2018JM5021);2017年陕西省创新学院大学生创新创业训练子项目资助

摘　　要：为了进一步提高镁合金表面Ni-Mo-P镀层的耐蚀性,采用0M、XRD和浸泡试验等方法,研究了退火处理对AZ31镁合金表面Ni-Mo-P镀层组织与腐蚀性能的影响。结果表明:AZ31镁合金阳极氧化-化学镀Ni-Mo-P镀层表面为“胞状”组织,随着退火温度的升高或退火时间的延长,AZ31镁合金阳极氧化-化学镀Ni-Mo-P镀层的胞状组织逐渐细化,但镀层厚度降低,同时,非晶态Ni-Mo-P镀层组织逐渐向晶态转变,350℃退火1.0h具有较高的非晶化程度,退火处理后的Ni-Mo-P镀层由Mg、MgO、Mg2SiO4、Ni和Ni3P组成;退火使AZ31镁合金阳极氧化-化学镀Ni-Mo-P镀层耐蚀性降低,350℃退火1.0 h镀层具有相对较好的耐蚀性,这与镀层的厚度和非晶化程度有关。In order to improve the corrosion resistance of Ni-Mo-P coating on the surface of AZ31 magnesium alloy, the effect of heat treatment on the microstructure and corrosion resistance of Ni-Mo-P coating on the surface of AZ31 magnesium alloy was studied by optical microscopy, X-ray diffractometer and immersion test. Results showed that the surface of anodized-electroless Ni-Mo-P coating of AZ31 magnesium alloy presented a "cell-like" structure. With the increase of annealing temperature or the extension of holding time, the cell structure of anodizedelectroless Ni-Mo-P coating on AZ31 alloy was gradually refined, but the thickness of coating decreased. Meanwhile, the Ni-Mo-P coating changed from amorphous state to crystalline state. When treated at 350°C . for 1.0 h, the coating had higher degree of amorphous state, and the Ni-Mo-P coating after annealing treatment was composed of Mg, MgO, Mg2SO4 , Ni and Ni3P. Besides, annealing treatment reduced the corrosion resistance of anodized-electroless Ni-Mo-P coating of AZ31 magnesium alloy, and the sample treated at 350 °C for 1 h had better corrosion resistance, which was related to the thickness of coatings and the degree of amorphous state.

关 键 词：AZ31镁合金 阳极氧化 化学镀 Ni-Mo-P镀层 退火 组织 耐蚀性 

分 类 号：TQ153.2[化学工程—电化学工业] TG156[金属学及工艺—热处理]