(華南師范大學 廣東省微納光子功能材料與器件重點實驗室，廣州 510006)
摘 要: 為獲得耐磨性能優(yōu)異的Ni60A合金涂層，采用高功率光纖激光熔覆系統(tǒng)制備出無裂紋Ni60A涂層。利用OM、SEM、XRD、EDS及顯微硬度儀等分析測試手段，分別對熔覆層顯微組織形貌、相組成、相分布、微區(qū)成分及顯微硬度進行測定與分析；利用HT-500型磨損試驗機研究不同載荷下熔覆層高溫干摩擦磨損特性，理論計算體積磨損率；利用SEM和EDS分析磨損機理。結果表明：熔覆層組織主要由柱狀γ-Ni固溶體枝晶、層片狀Ni-Ni3B共晶、胞狀M23C6和顆粒狀CrB組成；涂層平均顯微硬度為560HV0.2，遠高于基材的顯微硬度220HV0.2；施加載荷為3 N時，熔覆層摩擦因數(shù)最低、磨損率最小，其值分別為0.82和4.8×10-5 mm3/(N？m)，主要磨損機制為輕度磨粒磨損和氧化磨損。
關鍵字: Ni60A合金；激光熔覆；顯微組織；磨損性能；光纖激光器
（Laboratory of Nanophotonic Function Materials and Devices of Guangdong Province,
South China Normal University, Guangzhou 510006, China）
Abstract:The crack-free Ni60A coating was fabricated by fiber laser cladding system to obtain good wear-resisting Ni60A coating. The microstructure morphology, phase constitution, phase distribution, the micro-zone composition and microhardness of the coating were measured and analyzed by OM, SEM, XRD, EDS and microhardness tester, respectively. The high temperature tribological behaviors under different applied loads were studied by HT-500 wear-testing machine, and volume abrasion rates were calculated. The wear mechanism was analyzed by SEM and EDS. The results indicate that microstructure of the coating consists of columnar γ-Ni dendrite, lamellar Ni-Ni3B eutectic, cellular M23C6 eutectic and granular CrB. The microhardness of the coating is 560HV0.2, which is far higher than that of the substrate (220HV0.2). At an applied load of 3 N, the friction coefficient and wear rate of the coating are all the minimum, separately with values of 0.82 and 4.8×10-5 mm3/(N？m), and the wear mechanism mainly includes mild abrasive wear and oxidation wear.
Key words: Ni60A alloy; laser cladding; microstructure; wear performance; fiber laser
