摘要
利用微细电火花不同工艺加工了稀土镁合金.采用SEM和XPS分析了加工后稀土镁合金表面变质层形貌和成分,采用纳米压痕仪分析了变质层的硬度,采用动电位极化曲线评价了变质层的耐腐蚀性能.结果表明,变质层表面有微裂纹,降低加工电压和电流可以减少微裂纹,增大脉宽和脉间可以有效消除微裂纹;在3种不同介质中加工得到的变质层表面均发生了氧化反应,在去离子水中加工的变质层表面还发生了显著的电化学腐蚀;变质层的硬度高于稀土镁合金基体,其最高硬度可达到1.664 GPa;动电位极化曲线表明,变质层可以改善稀土镁合金的耐腐蚀性能.
In this work, the M^RE alloy metamorphic layer was formed in the micro-EDM process in different process parameters. The morphology and composition of the metamorphic layer were detected by SEM and XPS, the hardness of the metamorphic layer was measured by a nanoinden- tor, the corrosion resistance property was investigated by using a potentiodynamic polarization test. The results show that there are microcracks on the surface of metamorphic layer, the microcracks can be reduced by decreasing processing voltage and current, and it can be further eliminated by increasing pulse wide and pulse interval. The oxidation caused on the surface of metamorphic layers in the micro-EDM process in three different dielectrics among which there was significantly electrochemical corrosion on the surface in deionized water. The hardness of metamorphic layer is enhanced compared to the substrate of Mg RE alloy, and its maximum value is about 1.664 GPa. The potentiodynamic polarization test shows that the corrosion resistance of the Mg-RE alloy was improved significantly due to the existence of the metamorphic layer.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第2期251-256,共6页
Acta Metallurgica Sinica
基金
国家高技术研究发展计划资助项目2009AA044205~~
关键词
稀土镁合金
微细电火花
变质层
硬度
腐蚀
Mg-RE alloy, micro-EDM, metamorphic layer, hardness, corrosion
