摘要
采用激光熔覆技术,在304不锈钢基体上制备了AlCoCrFeNiNb0.75+WC(0%、10%、15%、20%、25%)高熵合金涂层,研究了WC含量对涂层的相组成、微观组织、硬度及摩擦磨损性能的影响。结果表明:未添加WC时,高熵合金涂层为BCC与Laves两相交替生长的共晶组织。向AlCoCrFeNiNb0.75合金中添加WC后,WC颗粒完全分解,生成了不规则十字花及多瓣状的灰色NbC金属间化合物,共晶组织发生解离并逐渐消退。随着WC含量的增加,NbC含量增多,共晶组织减少,当WC含量加至25%时,共晶组织完全消失,Laves相开始聚集生长。其中,当WC含量为15%时,涂层平均硬度最高,达825HV,约为不锈钢基体的4倍。当WC含量为10%时,涂层的磨痕宽度、深度最小,磨损程度最轻,表现出了最优的耐磨性。
AlCoCrFeNiNb0.75+WC(0%,10%,15%,20%,25%)high-entropy alloy coatings on 304 stainless steel were prepared by laser cladding technology.The effects of WC content on the phase composition,microstructure,hardness,friction and wear property of the coating were investigated.The results show that the microstructure of the high-entropy alloy coating without WC is eutectic microstructure formed by the alternative growth of BCC and Laves phase.WC particles dissolves totally after being added into the AlCoCrFeNiNb0.75alloy,which results in the formation of gray NbC phase with abnormal cruciate and multivalve-shapes,and the eutectic microstructure decomposes and vanishes gradually.With WC content increasing,the contnet of NbC phase increases,while the eutectic microstructure decreases.When the WC content reaches25%,there is no eutectic microstructure appearing in the alloy,and the Laves phase tends to aggregate and grow.When the content of WC is 15%,the average microhardness of the coating is the highest,reaching 825 HV,which is about four times as high as that of the substrate.When WC content is 10%,the wear scar width and depth of the coating is the smallest and the wear degree is the lightest,which indicates the best wear resistance.
作者
李大艳
姜慧
邹龙江
曹志强
LI Dayan;JIANG Hui;ZOU Longjiang;CAO Zhiqiang(School of Material Science and Engineering,Dalian University of Technology,Dalian 116024,China)
出处
《热加工工艺》
北大核心
2019年第10期117-121,126,共6页
Hot Working Technology
基金
国家自然科学基金资助项目(51574058)
关键词
激光熔覆
高熵合金
涂层
WC含量
laser cladding
high-entropy alloy
coating
WC content
