钴基合金渗层对钛合金耐磨、抗蚀性能的影响

发布时间：2018-04-25 22:11

本文选题：双层辉光离子渗 + 钴基合金　；参考：《稀有金属》2017年06期

【摘要】：采用双层辉光渗金属技术在Ti6Al4V钛合金表面制备钴基合金层以增强其耐磨、抗蚀性能,并考察了进行后喷丸复合以改善高温处理中对基材疲劳抗力损伤的处理对其性能的影响。利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、辉光放电光谱仪、显微硬度计、静态压入和动态压压疲劳设备分析和评价了钴基合金渗层的结构、成分分布、硬度和表面韧性,借助球-盘磨损试验机和电化学工作站研究了改性层对基材的干磨损行为和抗3.5%NaCl(质量分数)水溶液电化学腐蚀性能的影响。结果表明:在钛合金表面制备出由20μm沉积层和约5μm扩散层组成的钴基合金渗层,组成元素呈梯度渐变分布,表面硬度达HK_(0.98)N718,由于基材表面硬度提高了近一倍并具有良好的减摩润滑特性,使钛合金表面耐磨性提高了28倍,同时该渗层在3.5%NaCl(质量分数)水溶液中呈现良好的钝化特性,抗腐蚀性能优于钛合金基材。经陶瓷丸以0.15 mm A强度(Almen强度)喷丸后处理的钴基合金渗层的上表面沉积层减薄了1/5,表面硬度稍有增加,且表层硬度梯度呈现出一定程度的变缓,表面韧性却明显增强,但喷丸处理不仅使得钴基渗层表面耐磨性有所降低,其磨损率仅为钛合金的1/10,而且引起钴基合金渗层抗电化学腐蚀性能稍劣于钛合金基材。
[Abstract]:Co-base alloy layer was prepared on the surface of Ti6Al4V titanium alloy by double-layer glow permeation technique to enhance its wear resistance and corrosion resistance. The effect of post-shot blasting on the fatigue resistance of Ti6Al4V titanium alloy was investigated in order to improve the fatigue resistance of the substrate during high temperature treatment. The structure, composition distribution, hardness and surface toughness of cobalt-based alloying layer were analyzed and evaluated by means of scanning electron microscope (SEM), X-ray diffractometer (XRD), glow discharge spectrometer (GDS), microhardness tester, static indentation and dynamic compressive fatigue equipment. The effects of the modified layer on the dry wear behavior of the substrate and the electrochemical corrosion resistance of 3.5% NaCl-aqueous solution were studied by means of a ball disk wear tester and an electrochemical workstation. The results show that the cobalt-based alloying layer composed of 20 渭 m deposit layer and about 5 渭 m diffusion layer is prepared on the surface of titanium alloy. The surface hardness of the titanium alloy is up to HKD 0.98 N718.The surface hardness of the base material has been increased by nearly twice and has good antifriction and lubrication properties, which has improved the wear resistance of the titanium alloy surface by 28 times, and the layer has a good passivation property in the 3.5 NaCl-water solution. The corrosion resistance is superior to that of titanium alloy substrate. After peening with ceramic pellets with 0.15 mm A strength and Almen strength), the deposit layer on the upper surface of cobalt-based alloy was reduced by 1 / 5, the surface hardness increased slightly, and the hardness gradient of the surface layer decreased to a certain extent, but the surface toughness was obviously enhanced. However, shot peening not only reduced the wear resistance of cobalt-based coating, but also caused a slight deterioration of the electrochemical corrosion resistance of cobalt-based alloy coating than that of titanium alloy substrate, and the wear rate of the coating was only 1 / 10 of that of titanium alloy, and the electrochemical corrosion resistance of the coating was slightly worse than that of titanium alloy substrate.
【作者单位】：西安建筑科技大学冶金工程学院;西北工业大学腐蚀与防护研究所;
【基金】：陕西省教育厅专项科研计划项目(2013JK0916) 国家自然科学基金项目(51171154)资助
【分类号】：TG174.4

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