Yang Husen, Li Wen, Liu Yichun, Li Fengxian, Yi Jianhong, Eckert Jürgen
Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China.
Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstrasse 12, A-8700 Leoben, Austria.
Micromachines (Basel). 2024 Aug 25;15(9):1071. doi: 10.3390/mi15091071.
Ni60/60% WC composite coatings with a good surface roughness and high mechanical properties were successfully prepared on 316L stainless steel substrate by laser-directed energy deposition (LDED) technology. The effects of laser power on the microstructural evolution and mechanical properties of the Ni60/60% WC composite coating were investigated. The relationships between the chemical composition, the microstructure, the hardness, and the friction wear resistance of the composite coatings were characterized and investigated. The results show that the laser power had a significant effect on the energy input, which determined the melting extent of the Ni60 phases around the WC particles and the bonding strength between the reinforcements and the matrix, as well as the bonding strength between the substrate and the coatings. With an increase in the laser power from 800 W to 1400 W, the average hardness of the coating surface increased due to the increased densification of the deposited coatings and then decreased due to grain coarsening under a high energy input. The average coefficient of friction of the coatings decreased gradually to 0.383 at 1000 W, showing a minimum wear of 0.00013 mm at 1200 W. The main wear mechanisms on the coated surfaces were adhesive wear and abrasive wear. Moreover, the coatings deposited at 1200 W exhibited better forming quality and wear resistance. This work suggests that the processing parameters during LDED can be optimized to prepare Ni60/60% WC wear-resistant coatings with excellent mechanical properties.
采用激光直接能量沉积（LDED）技术在316L不锈钢基体上成功制备了具有良好表面粗糙度和高力学性能的Ni60/60%WC复合涂层。研究了激光功率对Ni60/60%WC复合涂层微观结构演变和力学性能的影响。对复合涂层的化学成分、微观结构、硬度和摩擦磨损性能之间的关系进行了表征和研究。结果表明，激光功率对能量输入有显著影响，能量输入决定了WC颗粒周围Ni60相的熔化程度、增强相与基体之间的结合强度以及基体与涂层之间的结合强度。随着激光功率从800W增加到1400W，涂层表面的平均硬度由于沉积涂层的致密化程度增加而升高，随后在高能量输入下由于晶粒粗化而降低。涂层的平均摩擦系数在1000W时逐渐降至0.383，在1200W时磨损最小，为0.00013mm。涂层表面的主要磨损机制为粘着磨损和磨粒磨损。此外，在1200W下沉积的涂层具有更好的成形质量和耐磨性。这项工作表明，可以优化LDED过程中的工艺参数，以制备具有优异力学性能的Ni60/60%WC耐磨涂层。
