脉冲频率对激光熔覆FeCoCrMoCBY涂层组织与性能的影响

发布时间：2018-08-11 16:05

【摘要】：通过脉冲激光熔覆技术在低碳钢表面上制备高致密铁基非晶合金涂层,研究了不同脉冲频率对涂层组织与性能的影响。利用光学显微镜(OM)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)、显微硬度仪、电化学工作站等测试方法分别分析了涂层成形、组织特征、显微硬度与耐腐蚀性能。研究结果表明,涂层主要由非晶组成,随脉冲频率降低,涂层厚度减小,稀释率降低,非晶化程度升高;当脉冲频率为1.0 Hz时,涂层稀释率显著降低50%,且未析出明显结晶相。随脉冲频率降低,熔合区宽度减小,柱状晶沿外延生长趋势变小,涂层显微硬度表现为先增加后减小,耐腐蚀性能先明显增强后减弱,且在3.5%NaCl溶液中耐腐蚀性能明显优于316L不锈钢。当脉冲频率为1.0 Hz时,涂层结构致密,平均显微硬度最高,达HV 1315,约为基材的9倍,涂层自腐蚀电流密度及钝化电流密度最低,分别为1.81×10~(-8),7.10×10~(-7)A·cm~(-2),耐蚀性能表现最强。
[Abstract]:High density Fe-based amorphous alloy coatings were prepared on the surface of low carbon steel by pulsed laser cladding. The effect of different pulse frequencies on the microstructure and properties of the coatings was studied. The forming, microstructure, microhardness and corrosion resistance of the coating were analyzed by means of (OM) X-ray diffractometer, (XRD), scanning electron microscope, (SEM), microhardness tester and electrochemical workstation. The results show that the coating is mainly composed of amorphous, with the decrease of the pulse frequency, the thickness of the coating decreases, the dilution rate decreases and the degree of non-crystallization increases, and when the pulse frequency is 1.0 Hz, the dilution rate of the coating decreases significantly by 50% and the crystalline phase is not precipitated. With the decrease of pulse frequency, the width of fusion zone decreases, and the growth trend of columnar crystal along the epitaxial growth becomes smaller. The microhardness of the coating increases first and then decreases, and the corrosion resistance first increases and then weakens. The corrosion resistance in 3.5%NaCl solution is better than that in 316L stainless steel. When the pulse frequency is 1.0 Hz, the coating structure is compact and the average microhardness is the highest, which is about 9 times of that of the substrate, and the self-corrosion current density and passivation current density of the coating are the lowest (1.81 脳 10 ~ (-8) and 7.10 脳 10 ~ (-7) A cm ~ (-2), respectively. The corrosion resistance of the coating is the strongest.
【作者单位】：南昌航空大学轻合金加工科学与技术国防重点学科实验室;北京科技大学新金属材料国家重点实验室;江西省电力设备总厂;
【基金】：国家自然科学基金项目(51461031) 江西省教育厅基金项目(GJJ150733);江西省教育厅科技落地计划项目(KJLD14055,20161BBH80031)资助国家重点实验室开放基金项目(2013-Z05) 北京市自然科学基金项目(2142022)
【分类号】：TG174.4

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