离子注入对LaFe11.6Si1.4合金的缓蚀及其机理研究

目的通过表面Cr离子注入在LaFe_(11.6)Si_(1.4)合金表面生成一层具有耐蚀作用的保护层,从而提高合金的耐腐蚀性能。方法采用表面离子注入法,分别在注入电压为20、30、40 k V,注入计量为5×10~(16)、10×10~(16)、50×10~(16) ions/cm~2的条件下注入Cr离子。利用扫描电子显微镜及X-射线衍仪对合金的表面形貌、组织结构及成分进行了分析,通过电化学方法对合金表面离子注入后的耐腐蚀性进行了研究。结果当Cr离子的注入电压为40 k V,注入剂量为5×10~(16)、1×10~(17)、5×10~(17) ions/cm~2时,合金的开路电位分别是-0.585、-0.584、-0.57V(vs.SCE)。当Cr离子的注入剂量为5×10~(17) ions/cm2,注入电压为20、30、40 k V时,合金的开路电位分别是-0.63、-0.61、-0.57 V(vs.SCE)。可以看到,随着Cr离子注入计量和注入电压的增加,合金表面的腐蚀电位正向移动,耐腐蚀性提高。结论 Cr离子注入能够显著提高合金的耐腐蚀性,分析认为主要是由于合金表面生成了一层具有耐腐蚀性能的Cr_2O_3钝化层。此外,由于注入离子的轰击导致表面La(Fe,Si)13相分解生成α-Fe,也提高了合金的电极电位,增强了耐腐蚀性。

Corrosion Inhibition and Mechanism of LaFe11.6Si1.4 Alloy Implanted with Ions

The work aims to improve the corrosion resistance of the alloy through the one anti-corrosion protective layer produced on the surface of LaFe11.6Si1.4 alloy after the Cr ion implantation. By means of surface ion implantation, Cr ions were implanted when the implantation voltages were respectively 20 kV, 30 kV and 40 kV, and the implantation dosages were 5×1016 ions/cm2, 10×1016 ions/cm2 and 50×1016 ions/cm2. Electron scanning microscope and X-ray spectroscope were used to analyze the morphology and structure as well as compositions of alloy. The corrosion resistance of alloy implanted with surface ions was studied in the electrochemical method. When the implantation voltage of Cr ion was 40 kV, the implantation dosages were 5×1016 ions/cm2, 1×1017 ions/cm2 and 5×1017 ions/cm2, respectively and the open-circuit potentials of alloy were respectively-0.585,-0.584 and-0.57 V (vs. SCE). When the implantation dosage of Cr ions was 5×1017 ions/cm2, the implantation voltages were respectively 20 kV, 30 kV and 40 kV, and the open-circuit potentials of alloy were respectively-0.63,-0.61-0.57 V (vs. SCE). These results showed that with the increase in the implantation dosage and implantation voltage of Cr ions, the corrosion potential on the alloy surface moved in the forward direction and the corrosion resistance was improved. Conclusion The im-plantation of Cr ions has significantly improved the corrosion resistance of the alloy. Based on the analysis, the improved corro-sion resistance is mainly attributable to the one anti-corrosion Cr2O3 passivation layer generated on the alloy surface. In addi-tion,α-Fe from the surface phase La(Fe,Si)13 caused by the bombardment of implanted ions has also improved the electrode po-tential of alloy and enhanced the corrosion resistance.