镁合金表面超音速等离子喷涂Al-Al2O3/5YSZ涂层的组织与耐磨性能研究

    Study on Microstructure and Wear Resistance of Al-Al2O3/YSZ Coatings on Magnesium Alloy Prepared by Supersonic Plasma Spraying

    • 摘要: 采用超音速等离子喷涂技术,在AZ61镁合金表面制备了不同Al2O3陶瓷含量的Al-Al2O3(AA)涂层以及不同Al2O3/5YSZ陶瓷含量的Al-Al2O3/5YSZ(AAZ)涂层,研究了YSZ的加入以及陶瓷含量对涂层微观组织、孔隙率、显微硬度以及耐磨性能的影响。结果表明,AAZ涂层的截面组织相比AA涂层得到了细化,组织更为均匀,减少了Al2O3相中的孔隙,YSZ以带状和微小球形颗粒弥散分布。涂层的显微硬度随着Al2O3/5YSZ含量的增加而增大,相比AA涂层,AAZ涂层具有更高的硬度值。在滑动摩擦磨损试验中,AAZ涂层硬度的提升使涂层的黏着磨损程度相较AA涂层降低。50%陶瓷含量的AAZ涂层的耐磨性低于30%和70%陶瓷含量的涂层,涂层原始组织中大量的相界面缝隙降低了金属相与陶瓷颗粒的粘结强度,导致陶瓷颗粒的脱落,增加了摩擦系数和磨损速率。30%陶瓷含量的AAZ涂层发生了磨粒磨损和黏着磨损。70%陶瓷含量的AAZ涂层具有最优的耐磨性,磨痕中散落的磨屑在磨损中起到了减摩润滑的作用。

       

      Abstract: Al-Al2O3(AA) coatings with different Al2O3 contents and Al-Al2O3/5YSZ (AAZ) coatings with different Al2O3/5YSZ contents were prepared on the surface of AZ61 magnesium alloy by supersonic plasma spraying technology, and the effects of YSZ addition and ceramic content on the microstructure, porosity, microhardness and wear resistance of the coatings were studied. The results show that the cross-sectional structure of AAZ coatings is refined compared with that of AA coatings, the structure is more uniformly, the pores in Al2O3 phase are reduced, and YSZ is diffusely distributed with ribbon and microscopic spherical particles. The microhardness of the coating increases with the increase of Al2O3/5YSZ content, and the hardness of AAZ coatings has a higher hardness than that of AA coatings. In the sliding friction wear test, compared with the AA coatings, the degree of adhesive wear of the AAZ coatings is reduced by the increase of the hardness of the coatings. The wear resistance of the AAZ coating with ceramic content of 50% is lower than that of the AA coatings with ceramic content of 30% and 70%, a large number of pores at the phase interface in the original structure of the coating reduce the bonding strength between the metal phase and the ceramic particles, resulting in the shedding of the ceramic particles, increasing the friction coefficient and wear rate. The AAZ30 coating with ceramic content of 30% undergoes abrasive wear and adhesive wear. AAZ coating with ceramic content of 70% has the best wear resistance, and the abrasive dust scattered in the wear marks play a role in anti-friction and lubrication during wear.

       

    /

    返回文章
    返回