Bao Junfeng, Yu Yueguang, Liu Bowen, Jia Chengchang, Wu Chao
Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China.
BGRIMM Technology Group, Beijing 100160, China.
Materials (Basel). 2020 Apr 24;13(8):1995. doi: 10.3390/ma13081995.
New coatings resistant to corrosion in high-temperature molten zinc aluminum were prepared by supersonic flame spraying of various composite powders. These composite powders were prepared by mixing, granulation, and heat treatment of various proportions of Mo-BC powder and WC and Co powder. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), energy dispersive X-ray spectroscopy (EDS), and mechanical analysis were used to study the effects of Mo-BC on the microstructure, phase, porosity, bonding strength, and elastic modulus of the composite powder and coating. Results show that the addition of an appropriate quantity of Mo-BC reacts with Co to form ternary borides CoMoB and CoMoB. Ternary boride forms a perfect continuous interface, improving the mechanical properties and corrosion resistance property of the coating. When the amount of Mo-BC added was 35.2%, the mechanical properties of the prepared coating reached optimal values: minimum porosity of 0.31 ± 0.15%, coating bonding strength of 77.81 ± 1.77 MPa, nanoindentation hardness of 20.12 ± 1.85 GPa, Young's modulus of 281.52 ± 30.22 GPa, and fracture toughness of 6.38 ± 0.45 MPa·m.
通过对各种复合粉末进行超音速火焰喷涂，制备了耐高温熔融锌铝合金腐蚀的新型涂层。这些复合粉末是通过将不同比例的Mo-BC粉末与WC和Co粉末进行混合、造粒和热处理而制备的。采用X射线衍射（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、高角度环形暗场扫描透射电子显微镜（HAADF-STEM）、能量色散X射线光谱（EDS）和力学分析等手段，研究了Mo-BC对复合粉末和涂层的微观结构、相、孔隙率、结合强度和弹性模量的影响。结果表明，添加适量的Mo-BC与Co反应形成三元硼化物CoMoB和Co₂MoB。三元硼化物形成了完美的连续界面，提高了涂层的力学性能和耐腐蚀性能。当Mo-BC的添加量为35.2%时，制备涂层的力学性能达到最佳值：最小孔隙率为0.31±0.15%，涂层结合强度为77.81±1.77MPa，纳米压痕硬度为20.12±1.85GPa，杨氏模量为281.52±30.22GPa，断裂韧性为6.38±0.45MPa·m。
