冷喷涂辅助原位合成CuFeCrAlNiTi高熵合金涂层的组织性能研究

Microstructure and Properties of CuFeCrAlNiTi 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性能,提出了一种在普通金属材料表面制备性能较好的CuFeCrAlNiTi高熵合金涂层的技术工艺。方法采用Cu、Fe、Cr、Al、Ni、Ti六种金属单质粉末为原料,经过2h机械混合后,使用低压冷喷涂技术在45^(#)钢基体上制备混合金属涂层,再经感应重熔技术将混合金属涂层原位合成为CuFeCrAlNiTi高熵合金涂层。采用扫描电子显微镜(SEM)、能谱仪(EDS)及X射线衍射仪(XRD),对混合金属涂层和原位合成CuFeCrAlNiTi高熵合金涂层的微观组织和相结构进行观察分析,并对原位合成CuFeCrAlNiTi高熵合金涂层的硬度、摩擦性能及耐腐蚀性能进行检测分析。结果原位合成CuFeCrAlNiTi高熵合金涂层组织致密、元素分散均匀;涂层结构是简单的固溶体结构BCC相和FCC相。涂层的综合性能良好,硬度可达543.4HV,与Al_(2)O_(3)的干摩擦因数为0.428,是45^(#)基体与Al_(2)O_(3)的干摩擦因数的61.6%,且较基体有更好的耐氯盐腐蚀性能,并在1 mol/L的Na Cl溶液和0.5 mol/L的H_(2)SO_(4)溶液中电化学腐蚀后,涂层中都不会形成腐蚀产物。结论使用冷喷涂辅助原位合成的CuFeCrAlNiTi高熵合金涂层具有相对较高的硬度、较好的摩擦性能以及耐氯盐腐蚀性能。

In order to improve the surface properties of common metal materials,a new technology for preparing CuFeCrAlNiTi high entropy alloy coating with good properties was proposed.In this paper,Cu,Fe,Cr,Al,Ni and Ti are used as raw materials.After 2 hours of mechanical mixing,the mixed metal coating is prepared on the 45^(#)steel matrix by low-pressure cold spraying technology.Then,the mixed metal coating is synthesized in-situ into CuFeCrAlNiTi high-entropy alloy coating by induction remelting technology.Scanning electron microscope(SEM),energy spectrum(EDS)and X-ray diffraction(XRD)were used to observe and analyze the microstructure and phase structure of the mixed metal coating and the in-situ synthesis CuFeCrAlNiTi high-entropy alloy coating,and the hardness,friction and corrosion resistance of the in-situ synthesis CuFeCrAlNiTi high-entropy alloy coating were analyzed.The results showed that CuFeCrAlNiTi high entropy alloy coating was prepared in situ with fine microstructure and uniform element dispersion.The coating structure is the simple solid solution structure BCC phase and FCC phase.The coating has a good comprehensive performance with a hardness up to 543.4HV,and the dry friction coefficient with Al_(2)O_(3) is 0.428,which is 61.6%of the dry friction coefficient between 45^(#)and Al_(2)O_(3).Besides,the coating has a better chlorine-resistant performance than the matrix,and will not form corrosion derivatives in the coating after the electrochemical corrosion of 1 mol/L NaCl solution and 0.5 mol/L H_(2)SO_(4) solution.Therefore,CuFeCrAlNiTi high-entropy alloy coating synthesized in situ by cold spraying has relatively high hardness,good friction and chloride corrosion resistance.