机械合金化法制备NiCrAlCoY涂层的研究

Study of NiCrAlCoY Coating Prepared by Mechanical Alloying

采用高能球磨机在室温下于碳钢表面制得NiCrAlCoY涂层,利用SEM、EDS、XRD、显微硬度测试和高温氧化实验等方法分析涂层的显微形貌、组织结构、显微硬度及高温氧化性,并对机械合金化过程中基体表面形成涂层的机理作了初步探讨。研究结果表明,提高球磨转速有利于涂层厚度、显微硬度的增加和抗高温氧化性的提高;以400r/min球磨10h时,碳钢表面形成界面结合良好且平均厚度为50μm的NiCrAlCoY涂层;合金涂层显微硬度HV0.1最大达706,约为基体硬度的3倍;界面结合处的硬度呈梯度变化,对涂层起到良好的支撑作用,而涂层的存在显著提高了基体的抗高温氧化性能。

NiCrAlCoY coating was obtained at room temperature on the carbon steel surface with a high-energy ball mill.SEM,EDS,XRD,microhardness test technique and high-temperature oxidation experiment were employed to investigate morphology,structure,microhardness and high-temperature oxidation resistance of the coating.Coating formation mechanism on substrate surface is discussed in the process of mechanical alloying.The results show that increasing ball rotation speed can improve the thickness,microhardness and high-temperature oxidation resistance of the coating.A 50 μm thick NiCrAlCoY coating combined well with substrate is formed by ball milling at 400 r/min for 10 h.The maximum microhardness（HV0.1） of the coating reaches 706,about three times as high as that of the substrate.Interface microhardness presents gradient variation,playing a good role in supporting the coating.And the high-temperature oxidation resistance of substrate is improved significantly in the presence of the coating.