INFLUENCE OF ELECTROLYTIC PLASMA OXIDATION COATING ON TENSILE BEHAVIOR OF DIE-CAST AM50 ALLOY SUBJECTED TO SALT CORROSION
Three different thickness ceramic coatings were deposited on die-cast AM50 magnesium alloy in KOH and NaAlO_2 solution using electrolytic plasma oxidation (EPO) technology for corrosion prevention. Immersion corrosion tests were carried out in 3.5％ NaCl solution for 336 hours to investigate the effect of coating thicknesses on tensile and fracture behaviors of the coated AM50 alloys. The results show that the yield strength (YS) and ultimate tensile strength (UTS) of the coated AM50 alloy subjected to immersion corrosion increase with an increase in coating thicknesses. Further analyses on stress and strain curves indicate that the coating enhances the strain-hardening rates of the corroded alloy during its plastic deformation. SEM examination on the fractured surface manifests that the substrate AM50 alloys exhibit characteristics of ductile deformation with deep dimples. However, brittle features prevail on the fractured surface of the mixed layer of coating plus oxidation corrosion product. Micro cracks were observed between the mixed layer and the AM50 alloy substrate induced by corrosion and within the mixed layer induced by EPO process, which could be responsible for the brittle fracture.
Electrolytic plasma ozidation coating diecast AM50 salt corrosion
LIHONG HAN XUEYUAN NIE PENG ZHANG QIANG ZHANG HENRY HU
Department of Mechanical.Automotive & Materials Engineering, University of Windsor, Windsor, Ontario Canada N9B 3P4
国际会议
第五届先进材料与加工国际会议(Fifth International Conference on Advanced Materials and Processing ICAMP-5)
哈尔滨
英文
960-965
2008-09-03（万方平台首次上网日期，不代表论文的发表时间）