Ce(NO_(3))_(3)掺杂对Al-Zn-Mg-Y合金PEO涂层显微结构和耐磨性的影响

Effect of Ce(NO_(3))_(3) Doping on the Microstructure and Wear Resistance of Al-Zn-Mg-Y Alloy PEO Coating

针对航空用途的铝合金耐磨性差的问题,利用等离子体电解氧化(PEO)技术在Al-Zn-Mg-Y合金表面形成陶瓷涂层,研究电解液中Ce(NO_(3))_(3)掺杂量对铝合金PEO涂层性能的影响。利用XRD、SEM、金相显微镜、共聚焦显微镜和摩擦磨损试验机等仪器对铝合金PEO涂层的相组成、金相组织、表面形貌、显微硬度、摩擦因数等参数进行表征。研究结果表明,Al-Zn-Mg-Y合金表面的PEO涂层主要由α-Al_(2)O_(3)和γ-Al_(2)O_(3)两相构成,随着Ce(NO3)3掺杂量增加,α-Al_(2)O_(3)相衍射峰增强,α-Al_(2)O_(3)相比例含量增加。掺杂Ce(NO_(3))_(3)后获得的PEO涂层覆盖较为均匀。在基础电解液中制备的PEO涂层,表面存在“火山口”状的放电微孔通道。增加Ce(NO_(3))_(3)掺杂量,则涂层中放电微孔通道尺寸减小。当Ce(NO_(3))_(3)掺杂量过高时,涂层表面出现腐蚀坑和少量微裂纹。随着Ce(NO_(3))_(3)掺杂量增加,PEO涂层的显微硬度呈现先增加后降低的趋势,在Ce(NO_(3))_(3)掺杂量为0.39%时出现最大值,约为335.8 HV1。掺杂适量的Ce(NO_(3))_(3)能够提高涂层的致密性,但过高Ce(NO_(3))_(3)掺杂量下,PEO涂层的摩擦因数增加,表面粗糙度增加。

In view of the poor wear resistance of aluminum alloy used in aviation,plasma electrolytic oxidation(PEO)technology was used to form ceramic coating on the surface of Al-Zn-Mg-Y alloy,and the effect of Ce(NO_(3))_(3) doping amount in electrolyte on the performance of aluminum alloy PEO coating was studied.XRD,SEM,metallographic microscope,confocal microscope and friction and wear tester were used to characterize the phase composition,metallographic structure,surface morphology,microhardness,friction coefficient and other parameters of PEO coating of aluminum alloy.The results show that the PEO coating on the surface of Al-Zn-Mg-Y alloy is mainly composed ofα-Al_(2)O_(3)andγ-Al_(2)O_(3).With the increase of Ce(NO_(3))_(3) doping,the diffraction peak of Al_(2)O_(3)phase is strengthened,the proportion content of Al_(2)O_(3)phase increases.The PEO coating obtained by doping Ce(NO_(3))_(3)is uniform.The surface of the PEO coating prepared in the basic electrolyte has a"crater"shaped discharge microporous channel.With the increase of Ce(NO_(3))_(3)doping,the size of discharge microporous channels in the coating decreases.When the doping amount of Ce(NO_(3))_(3)is too high,corrosion pits and a small amount of microcracks appear on the coating surface.With the increase of Ce(NO_(3))_(3)doping amount,the microhardness of PEO coating shows a trend of first increase and then decrease.The maximum value appears when Ce(NO_(3))_(3)doping amount is 3.9‰,about 335.8 HV1.Proper doping of Ce(NO_(3))_(3)can improve the density of the coating,but the friction coefficient and surface roughness of the PEO coating increases when the doping amount of Ce(NO_(3))_(3)is too high.