喷砂工艺对铝合金薄壁件表面状态和结合力的影响  

Effect of Sandblasting Process on Surface State and Adhesion of Al-alloy Thin Wall Parts

作　　者：李春 赵常益 张子昌[1] 李婷 马康智 倪立勇[1] 曲栋 杨震晓[1] 文波[1] Li Chun;Zhao Changyi;Zhang Zichang;Li Ting;Ma Kangzhi;Ni Liyong;Qu Dong;Yang Zhenxiao;Wen Bo(Institute of aerospace materials and processing technology,Beijing 100076)

机构地区：[1]航天材料及工艺研究所,北京100076

出　　处：《热喷涂技术》2022年第1期68-77,90,共11页Thermal Spray Technology

摘　　要：为了探明喷砂工艺对铝合金薄壁件表面粗糙度、基体变形以及涂层结合强度的影响,在2 mm厚的6061铝合金薄壁件表面采用24目和60目棕刚玉砂喷砂处理。喷砂压力选择0.3~0.5 MPa,喷砂次数1~15次,测试喷砂前后厚度、质量和表面粗糙度的变化,并分别采用扫描电镜、光学体式显微镜观察喷砂后表面形貌。在不同喷砂次数的铝合金表面喷涂YSZ热障涂层或涂覆丙烯酸聚氨酯涂层,采用拉伸法和划格法测试涂层的粘结强度。结果表明,1次喷砂后,铝合金基体的表面粗糙度(Ra)由0.35μm提高至4.747~11.49μm,厚度也略微增加,质量变化不明显,24目喷砂会造成基体表面明显变形。铝合金薄壁件多次喷砂后质量和厚度线性降低,随着砂粒粒径和喷砂压力的提高,质量和厚度的降低速率提高。铝合金1次、5次和15次喷砂后,其表面YSZ热喷涂涂层结合强度分别为23.53 MPa、24.80 MPa和17.28 MPa,有机涂层的附着力均达到0级。砂粒过大会造成铝合金薄壁件变形。影响喷砂表面粗化效果的主要因素是砂粒粒度,喷砂压力的影响较小。多次喷砂对表面粗糙度和涂层结合强度的影响不显著,但会造成基体厚度的减少和表面状态不均匀。This work aims to investigate the effects of sandblasting parameters on the surface roughness,matrix shape deformation and bonding strength of both inorganic and organic coatings on the Al-alloy thin wall parts.24-mesh and 60-mesh brown corundum sands were used for sandblasting on the surface of 2 mm thick 6061 Al-alloy thin wall plates.The sandblasting pressures were 0.3~0.5 MPa,respectively.The repeated sandblasting time varies between 1~15.The changes of thickness,quality and surface roughness before and after sandblasting were tested,and the surface morphology after sandblasting was observed by scanning electron microscope and 3D optical microscope.YSZ thermal barrier coating and acrylic polyurethane organic coating were separately prepared on the surface of Al-alloy with different sandblasting times.The bonding strengths of the coatings were tested by tensile method and cross cutting method.Results showed that after once sandblasting,the surface roughness(Ra)of Alalloy surface significantly increased from 0.35μm to 4.747~11.49μm.The thickness also increased slightly,and the quality change was not obvious.24-mesh sandblasting will cause obvious deformation of the substrate.The quality and thickness of Al-alloy thin wall plates decreaseed linearly with the sandblasting times.With the increase of sand particle size and sandblasting pressure,the reducing rate of quality and thickness increased.The bonding strength of APS YSZ thermal barrier coating on the surface of aluminum alloy was 23.53 MPa,24.80 MPa and 17.28 MPa respectively after 1,5 and 15 times of sandblasting,and the adhesion of organic coating reaches grade 0 for all the samples experienced sandblasting for 1~15 times.Excessive sand particles will cause deformation of Al-alloy thin wall parts.The main factor affecting the surface roughening effect of sandblasting was sand particle size,while the influence of sandblasting pressure was limited.Repeated sandblasting showed no significant effect on the surface roughness and coating bonding strength,but

关 键 词：喷砂 薄壁件 表面粗糙度 基体变形 结合强度 

分 类 号：TG174.4[金属学及工艺—金属表面处理]