AZ80镁合金微弧氧化膜复合封孔工艺及其性能研究

Research on Composite Sealing Process and Performance of Micro-Arc Oxidation Film on AZ80 Magnesium Alloy

为了研究不同封孔处理方式对微弧氧化(MAO)后的AZ80镁合金陶瓷膜结构和性能的影响,采用扫描电镜(SEM)、X射线衍射仪(XRD)、电化学测试、摩擦磨损试验等表征手段进行研究。结果表明:经过NaOH前处理、聚甲基三甲氧基硅烷(PMTMS)及聚四氟乙烯(PTFE)复合封孔处理后,微弧氧化膜层表面孔洞封填效果最佳,膜层粗糙度降低,耐磨性有所改善。经复合封孔处理后膜层的自腐蚀电位E_(corr)由微弧氧化膜的-0.45 V正移到-0.12 V,自腐蚀电流密度J_(corr)由微弧氧化膜的1.79×10^(-5)A/cm^(2)下降至4.51×10^(-6)A/cm^(2),表明耐蚀性显著提高。

Characterization methods such as scanning electron microscopy(SEM),X-ray diffractometer,electrochemical test,and friction and wear test were used to study the effects of different sealing treatments on the microstructure and properties of AZ80 magnesium alloy ceramic films which have already treated by micro-arc oxidation(MAO).Results showed that after the NaOH pretreatment and polymethyl trime thoxy silane(PMTMS)/polytetra fluoroe thylene(PTFE)composite sealing treatment,the MAO films could obtain the optimal hole-sealing effect on the surface.In addition,the roughness of MAO films decreased,while the abrasion resistance was improved.After the composite sealing treatment,the corrosion potential(E_(corr))of the film layer moved positively from-0.45 V of the MAO film to-0.12 V,and the corrosion current density(J_(corr))of the film layer dropped from 1.79×10^(-5)A/cm^(2) of the MAO film to 4.51×10^(-6)A/cm^(2),indicating that the corrosion performance was significantly improved.