激光熔覆NiCoFeCrTi高熵合金涂层及其耐磨性能研究

为了提高45#钢的耐磨性能,采用CO2激光熔覆技术进行了NiCoFeCrTi高熵合金涂层的制备实验。采用X射线衍射仪、扫描电镜和能谱仪分别分析了高熵合金熔涂层的物相结构、显微组织和化学成分。结果表明,由于高熵效应,NiCoFeCrTi涂层具有简单的面心立方相结构;在NiCoFeCrTi高熵合金涂层的熔覆层和结合区中未发现微裂纹,说明高熵合金与45#钢基底的冶金结合较好;熔覆涂层的表面显微硬度远远高于基底,维氏硬度可以达到940HV,是基底的3倍;表面熔覆了NiCoFeCrTi高熵合金的45#钢样品的磨损体积损失为5.010-10m3/m,低于45#钢的8.110-10m3/m。激光熔覆技术制备的NiCoFeCrTi高熵合金涂层可以显著提高45#钢耐磨损性能,对涂层应用研究具有较大参考意义。

Wear property of NiCoFeCrTi high entropy alloy coating by laser cladding

In order to improve the wear resistance of 45#steel, NiCoFeCrTi high entropy alloy coating was obtained by CO 2 laser cladding on 45#steel.The phase structure, microstructure and chemical composition of NiCoFeCrTi high entropy alloy layer were analyzed by X r-ay diffraction scanning electron microscope ( SEM ) and energy dispersive spectroscopy respectively .The result shows that the phase structure of NiCoFeCrTi high entropy alloy coating is face -centered cubic structure due to high-entropy effect.There are no micro-cracks in the cladding zone , the bounding zone and heat affected zone of NiCoFeCrTi high entropy alloy samples.The analysis of microstructure by SEM shows that the coating is metallurgically bonded to the substrate .The surface microhardness of NiCoFeCrTi high entropy alloys samples is up to 940 HV, about 3 times that of the substrate .The wear volume loss of 45#steel sample with NiCoFeCrTi high entropy alloy coating is 5.0 ×10 -10 m3/m, less than 8.1 ×10 -10 m3/m of 45# steel.The results show that , NiCoFeCrTi high entropy alloy coating prepared by laser cladding technology can significantly improve the wear resistance of 45# steel and it is meaningful to coating applications .