Sun Yijiao, Wang Weichao, Li Hongxiang, Xie Lu, Li Yongbing, Wang Shanlin, Wang Wenrui, Zhang Jiaming, Zhang Jishan
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China.
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Materials (Basel). 2021 Aug 24;14(17):4786. doi: 10.3390/ma14174786.
To solve the problem of poor corrosion and wear resistance of Mg-Li alloys, Fe-based amorphous coatings were prepared by high velocity oxygen-fuel spraying technology (HVOF) on the LA141 magnesium alloy substrate with a Ni60 intermediate layer. The microstructure and performance of Fe-based amorphous coatings with different oxygen flow and kerosene flow were characterized and analyzed. The results demonstrate that there is an optimal oxygen/kerosene ratio where the porosity of Fe-based amorphous coating is the lowest. Moreover, the amorphous content increases with the decrease in the oxygen/kerosene ratio. In particular, when the oxygen flow is 53.8 m/h and the kerosene flow is 26.5 L/h, the Fe-based amorphous coating possesses the lowest porosity (0.87%), the highest hardness (801 HV.), the highest bonding strength (56.9 MPa), and an excellent corrosion and wear resistance. Additionally, it can be seen that the Fe-based amorphous coating is composed of amorphous splats and amorphous oxides, but the Ni60 intermediate layer exhibits an amorphous and crystalline multi-phase structure. The high bonding strength of the coating is attributed to the low porosity of Fe-based amorphous coating and the localized metallurgical bonding between different layers. Finally, the mechanisms on corrosion and wear of Fe-based amorphous coatings are also discussed.
为解决Mg-Li合金耐蚀性和耐磨性差的问题,采用高速氧燃料喷涂技术(HVOF)在带有Ni60中间层的LA141镁合金基体上制备了铁基非晶涂层。对不同氧气流量和煤油流量下铁基非晶涂层的微观结构和性能进行了表征和分析。结果表明,存在一个最佳氧/煤油比,此时铁基非晶涂层的孔隙率最低。此外,非晶含量随氧/煤油比的降低而增加。特别是,当氧气流量为53.8 m/h且煤油流量为26.5 L/h时,铁基非晶涂层具有最低的孔隙率(0.87%)、最高的硬度(801 HV.)、最高的结合强度(56.9 MPa)以及优异的耐蚀性和耐磨性。此外,可以看出铁基非晶涂层由非晶薄片和非晶氧化物组成,但Ni60中间层呈现出非晶和晶体的多相结构。涂层的高结合强度归因于铁基非晶涂层的低孔隙率以及不同层之间的局部冶金结合。最后,还讨论了铁基非晶涂层的腐蚀和磨损机制。