高级检索

316不锈钢表面激光熔覆(FeCoCrNi)85(TiAl)15高熵涂层及其摩擦学行为研究

Study on tribological properties of 316 stainless steel surface laser cladding (FeCoCrNi)85(TiAl)15 high entropy alloy coating

  • 摘要: 为了增强316不锈钢(SUS316)的表面力学特性,通过激光熔覆技术结合同轴粉末输送方法,在SUS316表面制备了(FeCoCrNi)85(TiAl)15高熵合金熔覆层,采用X射线衍射、扫描电镜、电子透射分析技术等表征技术,连同维氏硬度仪和往复式摩擦磨损试验机对(FeCoCrNi)85(TiAl)15的微观组织、相组成、表面显微硬度、摩擦学特性及磨损机理进行了分析。结果表明,(FeCoCrNi)85(TiAl)15高熵合金的显微组织主要为等轴晶,且为含有面心立方(FCC)与体心立方的(BCC)双相结构,其中富Ti微米晶弥散分布于双相基体上,BCC基体中存在大量 01\overline1 BCC// 01\overline1 L21的共格析出;涂层表面维氏硬度为514 HV,较基体而言提高了66.9%;涂层在干滑动摩擦条件下的平均摩擦系数为0.331和磨损率为1.936×10−5 mm3/(N·m),相比于SUS316的平均摩擦系数0.418与磨损率2.906×10−5 mm3/(N·m),表现出显著的优势;磨痕形貌存在大量的犁沟和少量的黏着痕,说明磨损机理主要为磨粒磨损并伴有轻微黏着磨损。该研究可为利用激光熔覆直接实现FeCoCrNi系高熵合金涂层成分组织调控及提升摩擦磨损性能提供指导意义。

     

    Abstract: In order to enhance the surface mechanical properties of SUS316, the (FeCoCrNi)85(TiAl)15 high entropy alloy cladding layer was fabricated on the surface of SUS316 by laser cladding technology combined with coaxial powder conveying method. The microstructure, phase composition, surface microhardness, tribological characteristics, and wear mechanism of the high entropy alloy coating were analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscope, Vickers hardness tester, and reciprocating friction and wear testing machine, respectively. The results show that the microstructure of the (FeCoCrNi)85(TiAl)15 high entropy alloy coating is mainly equiaaxial, with face-centered cubic(FCC)+body-centered cubic (BCC) biphase structure. The Ti-rich micron crystals are dispersed on the surface of the biphase matrix, and a large amount of 01\overline1 BCC// 01\overline1 L21 coherent precipitation exists in the BCC matrix. The Vickers hardness of the coating surface is 514 HV, which is 66.9% higher than that of the substrate. The average friction coefficient and wear rate of dry sliding friction are 0.331 and 1.936×10−5 mm3/(N·m), respectively, which show significant advantages compared with 0.418 and 2.906 ×10−5 mm3/(N·m) of SUS316. A large number of furrows and a small number of adhesive marks can be observed, which indicates that the wear mechanism is mainly abrasive wear accompanied by slight adhesive wear. The relevant work can provide guidance for the direct control of composition structure and the improvement of friction and wear properties of FeCoCrNi high entropy alloy coatings by laser cladding.

     

/

返回文章
返回