冷喷涂辅助原位合成CuNiCoFeCrAl_(2.3)高熵合金涂层组织与性能研究

Microstructure and Properties of CuNiCoFeCrAl2.3 High Entropy Alloy Coating Prepared by Cold Spray Assisted in Situ Synthesis

目的为了提升普通金属材料的表面耐腐蚀和耐磨性能,提出了一种在普通金属材料表面制备性能良好的CuNiCoFeCrAl_(2.3)高熵合金涂层的技术工艺。方法利用冷喷涂技术在45#钢基体上制备混合金属涂层,再经过感应重熔技术将混合金属涂层原位合成为CuNiCoFeCrAl_(2.3)高熵合金涂层。通过采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、能谱仪(EDS)、显微硬度计、磨料磨损试验机等,对涂层的相组成、显微组织、硬度、耐磨性进行分析。结果原位合成CuNiCoFeCrAl_(2.3)高熵合金涂层组织致密,元素均匀分布,合金涂层由简单的BCC相构成,涂层的微观组织呈现出典型的枝晶结构。内枝晶区主要富含Co、Cr、Fe和Ni,枝晶间区则富含Cu和Al。CuNiCoFeCrAl_(2.3)高熵合金涂层的显微硬度是45#钢基体的3倍,在干摩擦条件下,CuNiCoFeCrAl_(2.3)高熵合金涂层在摩擦过程中以磨粒磨损为主,涂层在干滑动条件下的磨损率比45#钢基体的磨损率低59%,摩擦因数为0.38,约为45#钢基体的56%,CuNiCoFeCrAl_(2.3)高熵合金涂层的磨损率为2.95×10^(-5) mm^(3)/(N·m)。结论使用冷喷涂辅助原位合成CuNiCoFeCrAl_(2.3)高熵合金涂层具有很高的硬度和良好的耐磨性能。

In recent years,the rapid development of material surface treatment technology plays a particularly important role in the progress of modern science and technology,industry and economic development.Surface treatment technology is an important method to improve and repair matrix materials.It can improve the strength,hardness,wear resistance and corrosion resistance of materials.Preparing a layer of alloy coating on the surface of ordinary industrial materials is one of the most effective measures of surface treatment.high entropy alloy coating assisted in situ synthesis by cold spraying was prepared,This method can effectively eliminate the interface between powder particles in cold spraying coating.Improve the adhesion and cohesion of the coating,The adhesion of the coating can reach 120 MPa.In this method,the high entropy alloy powder is not required to be prefabricated,and the mixed metal powder is used as the spraying material to prepare the prefabricated mixed metal coating on the substrate.High entropy alloy coating was synthesized in situ by induction remelting technique.Therefore,this method has the advantages of low preparation cost,short cycle and easy to adjust the composition of the coating.High entropy alloys have high entropy effect in thermodynamics,lattice distortion effect in structure,hysteresis diffusion effect in dynamics,"cocktail"effect in performance and stability in structure.These effects give the alloys excellent mechanical properties such as high strength,good corrosion resistance and excellent wear resistance.These new metal materials are suitable for many engineering applications,Scholars prepared high entropy alloy as surface coating for wear and corrosion conditions,which can not only improve the service life and performance of metal parts,but also reduce the cost of preparation.In order to improve the surface corrosion and wear resistance of ordinary metal materials,a technology for preparing CuNiCoFeCrAl_(2.3)high entropy alloy coating with good performance on the surface of common metal materials was proposed.Methods The mixed metal coating was prepared on 45#steel by cold spraying at low pressure,and then synthesized into CuNiCoFeCrAl_(2.3)high entropy alloy coating by induction remelting technology.The phase composition,microstructure,hardness and wear resistance of the coating were analyzed by scanning electron microscope(SEM),X-ray diffraction(XRD)、energy dispersive spectrometer(EDS)、microhardness tester and abrasive wear tester.Results The microstructure of CuNiCoFeCrAl_(2.3)high entropy alloy coating was compact,the elements were uniformly distributed,the alloy coating was composed of simple BCC phase,and the microstructure of the coating showed typical dendrite structure.Co、Cr、Fe and Ni are mainly abundant in the inner dendrite region,while Cu and Al are abundant in the inter-dendrite region.The microhardness of CuNiCoFeCrAl_(2.3)high entropy alloy coating is three times that of 45#steel alloy matrix under dry friction condition.The wear rate of CuNiCoFeCrAl_(2.3)high entropy alloy coating under dry sliding condition is 59%lower than that of 45#steel substrate,and the friction coefficient is 0.38.The wear rate of CuNiCoFeCrAl_(2.3)high entropy alloy coating is 2.95×10^(-5) mm^(3)/(N·m).The CuNiCoFeCrAl_(2.3)high entropy alloy coating assisted by cold spraying has high hardness and excellent wear resistance.