盐浴渗氮处理对FeCrMnNiAl0.2Ti0.1高熵合金组织及性能的影响

采用盐浴渗氮的化学热处理方法对FeCrMnNiAl_0.2Ti_0.1高熵合金进行表面强化,主要工艺为预热+盐浴渗氮+氧化,研究渗氮温度对渗层和性能的影响。采用光学显微镜、扫描电镜、X射线衍射仪研究不同渗氮温度下高熵合金的组织结构和物相,利用显微硬度计和W-2000摩擦磨损试验机分别测量硬度和耐磨性。结果表明,经过盐浴渗氮后,高熵合金表面形成含氮化物和氧化物的复合渗层,渗氮层深度最高为27.1 μm,硬度最高可达1080.0 HV0.2。盐浴渗氮可以有效提高高熵合金的耐磨性,改善摩擦学行为,640 ℃渗氮试样的磨损率仅为0.025 mm³/(N·m),与铸态相比降低了约76.7%。

Effect of salt bath nitriding treatment on microstructure and properties of FeCrMnNiAl0.2Ti0.1 high entropy alloy

Chemical heat treatment method of salt bath nitriding was used to strengthen the surface of FeCrMnNiAl_0.2Ti_0.1 high entropy alloy, and the main process was preheating + salt bath nitriding + oxidation. The effect of nitriding temperature on infiltration layer and properties of the alloy was studied. The microstructure and phases of the tested alloy at different nitriding temperatures were studied by metallographic microscope, scanning electron microscope and X-ray diffractometer. The hardness and wear resistance of the alloy were measured by microhardness tester and W-2000 friction and wear tester, respectively. The results show that after salt bath nitriding, a composite nitrided layer containing nitride and oxide is formed on the surface of the alloy. The highest depth of nitrided layer is 27.1 μm and the hardness can reach 1080.0 HV0.2. Salt bath nitriding can effectively enhance wear resistance of the high entropy alloy and improve the tribological behavior. The wear rate of the nitrided specimen at 640 ℃ is only 0.025 mm³/(N·m), which is about 76.7% lower than that of the as-cast specimen.