激光熔覆高熔点AlCrFeMoNb_xTiW高熵合金涂层组织及耐磨性能

发布时间：2018-01-19 16:12

本文关键词： 激光熔覆 AlCrFeMoNbxTiW 高熔点高熵合金高速切削刀具耐磨性　出处：《稀有金属》2017年12期 　论文类型：期刊论文

【摘要】：为了提高高速切削刀具的表面耐磨性能,设计了一种高熔点高熵合金成分体系,采用激光熔覆技术制备了AlCrFeMoNb_xTiW高熵合金涂层。利用光学显微镜(OM),X射线衍射(XRD),扫描电镜(SEM)等手段对其显微组织进行表征分析;利用显微硬度计、摩擦磨损试验机对涂层硬度及耐磨性能进行了检测。结果表明:熔覆层相组成主要由BCC,(Nb,Ti)C及Laves相所组成;当Nb原子分数为1时,涂层显微组织为胞状树枝晶及颗粒状碳化物;随着Nb原子比增加,涂层组织逐渐由放射状共晶向长条树枝状过共晶组织转变,但弥散分布的颗粒状(Nb,Ti)C始终存在于涂层内部。涂层硬度逐渐上升,当Nb原子分数为7时,涂层的最高硬度可达HV0.21017。磨损实验表明,各个Nbx涂层的平均摩擦系数差别不大;磨损量随着Nb含量的升高而降低;涂层磨损机制主要以磨粒磨损为主。
[Abstract]:In order to improve the wear resistance of high speed cutting tools, a high melting point and high entropy alloy composition system was designed. AlCrFeMoNb_xTiW high entropy alloy coatings were prepared by laser cladding technique. Scanning electron microscopy (SEM) and other methods were used to characterize its microstructure. The hardness and wear resistance of the coatings were tested by microhardness tester and friction and wear tester. The results show that the phase composition of the cladding layer is mainly composed of BCC / NbTiC and Laves phase. When the NB atom fraction is 1:00, the microstructure of the coating is cellular dendrite and granular carbide. With the increase of NB atom ratio, the microstructure of the coating gradually changed from radial eutectic to long strip hypereutectic structure, but dispersed granular Nb. Ti)C always exists in the coating. The hardness of the coating increases gradually, and the highest hardness of the coating reaches HV0.21017 when the NB atom fraction is 7:00. The average friction coefficient of each Nbx coating is not different. The wear rate decreased with the increase of NB content. The wear mechanism of the coating is mainly abrasive wear.
【作者单位】：贵州大学材料与冶金学院;贵州省材料结构与强度重点实验室;
【基金】：贵州省高层次创新型人才培养项目[黔科合人才(2015)4009号] 贵州省工业攻关项目[黔科合GZ字(2015)3022号]资助
【分类号】：TG174.44
【正文快照】： 高熵合金因其热力学上的高熵效应、严重的晶格畸变和迟滞扩散等特点,在性能上表现出高强硬度、优异的耐磨、耐蚀性以及超高的高温稳定性能,具有较高的科研价值及工业应用前景[1]。因此,近些年在国内外材料领域掀起了一阵研究风潮[2-4]。以往的报道中,块状高熵合金的制备手段主

【相似文献】