Zr离子注入对镁合金表面耐磨耐蚀性能的影响

Effect of Zr ion implantation on wear resistance and corrosion resistance of magnesium alloy

在不引入外来元素的情况下,通过金属高能离子源(MEVVA)将不同剂量(1×10^16,2×10^16,3×10^16,5×10^16ions/cm^2)的锆元素注入ZK60镁合金表面。采用X射线光电子能谱(XPS)刻蚀技术分析了注入层的结构成分,利用摩擦磨损试验机研究了注入前后试样表面耐磨性能变化,通过电化学工作站研究了Zr离子注入前后ZK60镁合金在3. 5%Na Cl溶液中的耐腐蚀性能,根据电化学阻抗数据拟合等效电路,探讨其耐蚀机理。结果表明,注入剂量为2×10^16ions/cm^2时,ZK60镁合金表面形成一层主要由Zr O2、Zr和MgO组成的改性层,其表面耐磨性能得到改善;随着注入剂量的增加,其腐蚀电流密度先减小后增加,当注入剂量为2×10^16ions/cm^2时,其腐蚀电流密度下降了约两个数量级,表明Zr离子注入可有效提高ZK60镁合金的耐蚀性能。

Different doses of zirconium ( 1×10^16,2×10^16,3×10^16,5×10^16 ions /cm^2 ) were introduced into the surface of ZK60 magnesium alloy by metal vapor vacuum arc ( MEVVA) without introducing extraneous elements.The structure and composition of the implanted layer were analyzed by X-ray photoelectron spectroscopy ( XPS),the wear resistance of the sample before and after implantation was studied by friction and wear tester,and the corrosion resistance of the ZK60 magnesium alloy in 3. 5% NaCl solution before and after Zr ion implantation was studied by electrochemical workstation. According to the electrochemical impedance data and the fitting equivalent circuit,the corrosion resistance mechanism was discussed. The results show that when the implantation dose is 2 × 10^16 ions /cm^2,a modified layer composed mainly of ZrO2,Zr and MgO is formed on the surface of the ZK60 magnesium alloy,and its surface wear resistance is improved. With the increase of implantation dose,the corrosion current density of the alloy decreases at first and then increases,and when the implantation dose is 2×10^16 ions /cm^2,the corrosion current density decreases by about two orders of magnitude, indicating that Zr ion implantation can effectively improve the corrosion resistance of the ZK60 magnesium alloy.