激光冲击强化对AZ31B镁合金表面耐腐蚀行为的影响  

Effect of Laser Shock Strengthening on Corrosion Resistance of AZ31B Magnesium Alloy Surface

作　　者：刘朋锴 全红宇 欧阳文泰 原黎明 黄亿辉[2,3] 秦秀 张文武 Liu Pengkai;Quan Hongyu;Ouyang Wentai;Yuan Liming;Huang Yihui;Qin Xiu;Zhang Wenwu(College of Mechanical Engineering and Mechanics,Ningbo University,Ningbo 3152ll,Zhejiang,China;Ningbo Institute of Materials of Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,Zhejiang,China;Zhejiang Key Laboratory of Aero Engine Extreme Manufacturing Technology,Ningbo 315201,Zhejiang,China)

机构地区：[1]宁波大学机械工程与力学学院,浙江宁波315211 [2]中国科学院宁波材料技术与工程研究所,浙江宁波315201 [3]浙江省航空发动机极端制造技术研究重点实验室,浙江宁波315201

出　　处：《应用激光》2023年第4期117-128,共12页Applied Laser

基　　金：浙江省基础公益研究计划(LGG20E050009)。

摘　　要：镁合金具有密度小、比强度和比刚度高、机械加工性能好、生物相容性良好等优异性能,成为潜在新一代可生物降解骨板材料,但其耐腐蚀性能差,限制其发展。使用激光冲击强化技术(LSP),研究其对镁合金表面耐腐蚀性能的影响。采用激光功率密度为1.35 GW/cm^(2)、2.99 GW/cm^(2)和3.92 GW/cm^(2)进行冲击强化试验,在3.5%(质量分数)NaCl溶液中,通过电化学测量技术动电位扫描得到极化曲线,并通过微观结构探究激光冲击强化对AZ31B镁合金耐腐蚀性能的影响机理。试验结果显示,随着激光功率密度的提升,样品的表面硬度也随之提高,2.99 GW/cm^(2)样品的表面硬度为81.2 HV,相比原始样品提高了35.8%。XRD图谱显示,与原始样品相比,激光冲击处理后的样品衍射峰向高角度方向偏移,衍射峰强度均降低,半峰宽增加。2.99 GW/cm^(2)样品的耐腐蚀性能最好,腐蚀电位为-0.60241 V,腐蚀电流密度为1.0215×10^(-4 )A/cm^(2),相比原始样品腐蚀电位提升了50.47%,腐蚀电流密度降低了42.90%。Magnesium alloy has many excellent properties such as low density,high specific strength and specific stiffness,good mechanical processing performance,and good biocompatibility.Magnesium alloy has become a potential new generation of biodegradable bone plate materials,but its poor corrosion resistance limits its development.In this paper,the effect of laser shock peening(LSP)on the corrosion resistance of AZ31B magnesium alloy was studied by using different laser power densities of 1.35 GW/cm^(2),2.99 GW/cm^(2),3.92 GW/cm^(2),the polarization curves were obtained by electrochemical measurement technique of dynamic potential scanning in 3.5%(mass fraction)NaCl solution for comparison of corrosion resistance before and after laser shock.The influence mechanism of laser shock peening on the corrosion resistance of AZ31B magnesium alloy was studied by microstructure.The surface hardness of the sample increases with the increase of laser power density.The surface hardness of the 2.99 GW/cm^(2) sample is 81.2 HV,which is 35.8%higher than that of the original sample.XRD patterns show that compared with the original sample,the diffraction peak of the sample after laser shock treatment shifts to the high angle direction,the intensity of the diffraction peak decreases,and the FWHM increases.The 2.99 GW/cm^(2) sample has the best corrosion resistance,corrosion potential is-0.60241 V,corrosion current density is 1.0215×10^(-4)A/cm^(2),corrosion potential increased by 50.47%compared with the original sample,and corrosion current density decreased by 42.90%.

关 键 词：激光冲击强化 耐腐蚀性能 影响机理 镁合金 极化曲线 

分 类 号：TN249[电子电信—物理电子学]