纯钛表面等电位空心阴极辉光放电无氢渗碳的研究

Hydrogen-Free Carburization on the Surface of Commercial Purity Titanium by the Equipotential Hollow-Cathode Glow Discharge

摘要:

在纯钛相变温度下，利用等电位空心阴极辉光放电技术在纯钛表面进行无氢渗碳处理。分别利用扫描电子显微镜、能谱仪和X射线衍射仪对试样的表面形貌、成分分布和相组成进行分析；利用摩擦磨损试验仪对试样的摩擦学性能进行研究；利用电化学工作站，在常温静态条件下对试样在3.5%NaCl水溶液的耐蚀性能进行研究；结果显示，经过无氢渗碳处理，在纯钛表面形成了高硬度的合金改性层，改性层的最大厚度是7.5 μm，最大显微硬度是1298 HV0.2，是基体硬度的5.43倍。由于表面硬度的提高，试样的耐磨性能也显著增强，试样的平均摩擦系数是0.312，较原始试样的0.746明显降低。在3.5%NaCl水溶液中，试样的最低年腐蚀速率是原始试样的1/11。因此，在保证基体力学性能的前提下，试样的耐磨耐蚀性能明显提高。

Abstract:

The treatment of hydrogen-free carburization is applied on commercial purity titanium by the technology of equipotential hollow-cathode glow discharge under the commercial purity titanium phase transition temperature. The morphology, distribution of composition, phase composition are analyzed by the scanning electron microscope, the energy dispersive spectrometer, the X-ray diffraction, respectively; the tribology capability of the sample is studied by the friction and wear tester; the corrosion resistance of the samples in 3.5% NaCl solution is studied under the normal temperature static condition by using the electrochemical workstation. The results have shown that the high hardness alloy layer is formed on the commercial purity titanium surface by the treatment of hydrogen-free caburization, and the maximum thickness of the carburized layer is 7.5 μm; and the maximum hardness is 1298 HV0.2, which is 5.43 times that of the matrix. Due to the improved surface hardness, the wear resistance on the surface of the sample is increased significantly, and the average friction coefficient is only 0.312, which is obviously decreased than 0.746 that of the original sample. The minimum annual corrosion rate of the samples is 1/11 of the original sample in 3.5 mol/L NaCl solution. So the wear resistance and corrosion resistance are obviously improved in the premise of keeping the mechanics properties of the substrate.