(1. 東北大學 材料與冶金學院 材料各向異性與織構工程教育部重點實驗室，沈陽 110004；
2 江蘇大學 機械學院，鎮(zhèn)江 212013)
摘 要: 利用激光輔助直接金屬沉積技術在1018低碳鋼上沉積Co-285單壁墻，并利用優(yōu)化參數(shù)制得大面積沉積層。利用光學顯微鏡、附帶能譜儀的掃描電鏡、X射線衍射儀、顯微硬度計和磨損試驗機研究沉積單壁墻或沉積層的顯微組織、成分、物相、橫截面的顯微硬度分布和耐磨性。結(jié)果表明：沉積的單壁墻無氣孔和裂紋等缺陷，成形性能良好，且與基體形成冶金結(jié)合；單壁墻由枝晶和枝晶間共晶組成；所有工藝參數(shù)下單壁墻的硬度相差不大；當激光功率為0.8 kW、送粉率為8.6 g/min、掃描速度為0.375 m/min時，單壁墻硬度值最大，達到407HV0.5；在此參數(shù)下制得沉積層的組織與單壁墻的類似，其相組成為α-Co固溶體、富Cr的M23C6和Co3W；磨損60min后，沉積層體積損失為1.4 mm3；磨損機制為研磨磨損、粘著磨損和氧化磨損的混合磨損。
關鍵字: Co-285合金；單壁墻；金屬沉積；磨損
Co-285 alloy on carbon steels
（1. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China;
2. School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China）
Abstract:The laser-aided direct metal deposition (LADMD) technique was used to fabricate Co-285 single walls on 1018 mild steels, and large scale coatings were fabricated with optimal parameters. The microstructure, composition, phases, microhardness of the cross-section and wear resistance of the deposited single walls or coatings were analyzed by OM, SEM, XRD, microhardness tester and wear tester. The results indicate that the deposited single walls prepared with different parameters are pore and crack free, with good processability. A metallurgical bonding exists between the walls and substrates. The deposited single walls are composed of dendrites and eutectics, and the microhardness under different parameters varies a little, among which the highest hardness is 407HV0.5 when the laser power, powder flow rate and laser scanning speed are 0.8 kW, 8.6 g/min and 0.375m/min, respectively. The coating fabricated with the above parameters has the same structure as the deposited single walls, and the phases are α-Co solid solution, Cr-riched M23C6 and Co3W. After wear for 60min, the wear volume loss of the coating is 1.4 mm3, the wear mechanism is a mixture of abrasive, adhesive and oxidation wear.
Key words: Co-285 alloy; deposited wall; metal deposition; wear
