177 / 2021-04-05 17:58:16

激光熔覆AlxCoCrCuFeNi高熵合金涂层组织与耐磨性

激光熔覆；AlxCoCrCuFeNi高熵合金；涂层；摩擦磨损；非平衡凝固

                                                                                               激光熔覆Al_xCoCrCuFeNi高熵合金涂层组织与耐磨性

                                                                                                       张世一，韩彬，李美艳，张琪，胡春阳

                                                                                                 （中国石油大学（华东）， 山东青岛266580）

摘要：利用激光熔覆技术在45钢基体表面制备Al_xCoCrCuFeNi(x=0.5, 0.75, 1.0, 1.25, 1.5)高熵合金涂层，研究了Al元素含量对涂层组织结构、相组成、硬度及耐磨性的影响规律，重点分析了非平衡凝固快冷条件对高熵合金涂层形核的影响机制。Al_xCoCrCuFeNi涂层具有BCC和FCC结构，随Al元素含量的增加FCC逐渐向BCC转变，高熔点Fe，Cr元素偏聚于BCC相中，Cu元素以富Cu相形式存在。涂层硬度随Al含量的增加而增大，合金体系为Al_1.5CoCrCuFeNi时硬度达到最大为807.3HV_0.2，耐磨性与硬度呈正相关性。激光熔覆非平衡快冷条件抑制了金属间化合物等有序相的形核、生长，有利于高熵合金固溶体相的形成。

关键词：激光熔覆；Al_xCoCrCuFeNi高熵合金；涂层；摩擦磨损；非平衡凝固

                                               Microstructure and wear resistance of Al_xCoCrCuFeNi high-entropy alloy coatings by laser cladding

Abstract: Al_xCoCrCuFeNi(x=0.5, 0.75, 1.0, 1.25, 1.5) high-entropy alloy coatings were prepared on the surface of 45 steel by laser cladding. The effects of the Al content on microstructure, phase structure, hardness and wear resistance was investigated. The effects of non-equilibrium solidification condition on high-entropy alloy coatings nucleation was analyzed emphatically. The experimental results indicated that Al_xCoCrCuFeNi high-entropy alloy coatings were composed of BCC and FCC phase and FCC was converted into BCC phase with Al element increased. Fe and Cr elements were riched in BCC phase. The microhardness of coatings were increased due to Al element increased, the maximum was 807.3HV_0.2 when the alloy system was Al_1.5CoCrCuFeNi. Wear resistance and hardness are positively correlated. The non-equilibrium fast cooling condition of laser cladding inhibited the nucleation growth of intermetallic compounds and it has beneficial to form the solid solution phases.