铬铁原矿粉掺杂制备CrFeNiSiAl0.5高熵合金涂层及其组织性能

目的 以40Cr钢为基体,制备掺杂铬铁原矿粉的CrFeNiSiAl0.5高熵合金涂层,提高其硬度与耐磨性.方法 在Cr、Fe、Ni、Al、Si纯金属粉末中掺杂铬铁原矿粉,矿粉有效原子数分数为0％、5％、10％、15％时,采用激光熔覆技术,在40Cr钢基体上制备CrFeNiSiAl0.5高熵合金涂层.利用X射线衍射仪、金相显微镜、扫描电子显微镜,表征高熵合金涂层的物相结构及微观组织.利用硬度计、磨粒磨损机,对涂层的硬度及耐磨性能进行表征.结果 不含铬铁原矿粉时,高熵合金涂层为单一的BCC相,铬铁原矿粉为10％时,出现FCC相.高熵合金涂层微观组织以胞状树枝晶为主,涂层与结合区存在明显分界,与基体呈良好的冶金结合.不含铬铁原矿粉时,高熵合金涂层平均硬度值为643.5HV;铬铁原矿粉为15％时,涂层平均硬度值为838.1HV,是基体的3.4倍.磨损率随铬铁原矿粉占比的增加而降低,铬铁原矿粉有效原子数分数为15％时,磨损率约为0.14 mg/mm2,耐磨性能最好.结论 在40Cr钢基体上成功制备出了以铬铁原矿粉为掺杂组元的高熵合金涂层,铬铁原矿粉的掺入,提升了CrFeNiSiAl0.5高熵合金涂层的硬度与耐磨性.

Preparation of CrFeNiSiAl0.5 High Entropy Alloy Coating by Doping Chromite Powder and Its Microstructure and Properties

CrFeNiSiAl0.5 high entropy alloy coating doped with chromite powder was prepared on 40Cr steel to improve its hardness and wear resistance. CrFeNiSiAl0.5 high entropy alloy coating was prepared on 40Cr steel substrate by laser cladding technology when Cr, Fe, Ni, Al and Si pure metal powders were doped with chromite powder and the effective atomic number fraction of ore powder was 0%, 5%, 10% and 15%. The phase structure and microstructure of high entropy alloy coating were characterized by X-ray diffractometer, metallographic microscope and scanning electron microscope. The hardness and wear resistance of the coating were characterized by hardness tester and abrasive wear machine. The results show that the high-entropy alloy coating is a single BCC phase without the chromite powder, and the FCC phase occurs when the content of the chromite powder is 10%. The micro-structure of the high-entropy alloy coating is mainly in the form of a cell-like dendritic crystal, and the coating and the bonding area have obvious boundary, and the high-entropy alloy coating micro-structure is in good metallurgical bonding with the matrix. The average hardness value of the high-entropy alloy coating is 643.5HV when no chromite powder is contained. And the content of the chromite powder is 15%, the average hardness of the coating is 838.1HV, which is 3.4 times of the matrix, and the wear rate is reduced with the increase of the content of the chromite powder, and the wear rate is about 0.14 mg/mm2 when the content of the chromite powder is 15%, the wear resistance is the best. High entropy alloy coating with chromite powder as doping component was successfully prepared on 40Cr steel substrate. The hardness and wear resistance of CrFeNiSiAl0.5 high entropy alloy coating were improved by adding chromite powder.