热处理诱导铝硅合金涂层组织结构转变及其对高温摩擦学性能的影响  

Microstructure Transformation of Al-Si Alloy Coatings Induced by Heat Treatment and Its Effect on High Temperature Tribological Properties

作　　者：徐浩博 马国政 何鹏飞 李国禄[1] 刘明 郭伟玲 王海斗 XU Haobo;MA Guozheng;HE Pengfei;LI Guolu;LIU Ming;GUO Weiling;WANG Haidou(Materials Science and Engineering,Hebei University of Technology,Tianjin 300130,China;National Key Laboratory for Remanufacturing,Army Academy of Armored Forces,Beijing 100072,China;Defense Innovation Institute,Academy of Military Science,Beijing 100071,China;National Engineering Research Center for Remanufacturing,Army Academy of Armored Forces,Beijing 100072,China)

机构地区：[1]河北工业大学材料科学与工程学院,天津300130 [2]陆军装甲兵学院再制造技术国防科技重点实验室,北京100072 [3]军事科学院国防科技创新研究所,北京100071 [4]陆军装甲部队学院机械产品再制造国家工程研究中心,北京100072

出　　处：《中国表面工程》2025年第1期203-215,共13页China Surface Engineering

基　　金：国家自然科学基金(52075543、52122508、52105233);十四五预研项目。

摘　　要：为提升铝硅合金涂层的高温摩擦学性能,实现全铝合金发动机制造。使用超音速等离子喷涂工艺制备Al-40Si-5Fe涂层,并利用330℃时效处理诱导涂层组织结构发生转变。研究发现,原始喷涂态涂层组织呈现典型的层状堆叠结构,单个摊片上部由初生Si相和Al/Si共晶相组成,摊片下部由不完全非晶组织构成。330℃时效处理后,涂层组织均匀性明显改善,并且涂层内部形成具有圆润表面的网状Si相骨架。在220℃环境中,载荷3 N、行程4 mm、频率5 Hz的干摩擦试验条件下,330℃×24 h热处理态涂层的平均摩擦因数和磨损率分别为0.38和1.35×10^(-4)mm^(3)/(N·m),比原始喷涂态涂层的平均摩擦因数和磨损率分别降低19.1%和5.6%。喷涂态涂层的磨损机制为磨粒磨损和粘着磨损,330℃×24 h热处理态涂层的磨损机制以磨粒磨损为主,粘着磨损为辅。330℃×24 h热处理态涂层内的网状Si相结构可以在220℃环境中保持对基体的强化作用,从而有效减轻了涂层的塑性变形程度和摩擦副之间的粘着行为,对涂层的高温摩擦学性能有明显改善效果。Al-Si alloys are ideal materials for the preparation of aluminum alloy engines.However,the wear resistance of Al-Si alloys produced through casting technology is poor,making them unsuitable for use under harsh working conditions inside an engine.They can only be used to make external cylinder blocks.Coatings prepared by supersonic plasma spraying have advantages such as high bonding strength and a dense microstructure.Therefore,using supersonic plasma spraying technology to prepare structurally excellent Al-Si coatings on the surface of Al-Si alloys can improve their high-temperature friction performance,which is expected to facilitate the preparation of all-aluminum engines.In this study,Al-35Si-4Fe powder was used as the raw material,and ultrasonic plasma spraying was used to prepare an Al-Si alloy.Owing to the high heat input in the ultrasonic plasma spraying process,Al is burned out,thus achieving the in-situ preparation of Al-40Si-5Fe coatings.According to the differential scanning calorimetry analysis results of the Al-40Si-5Fe coating,heat treatment of the Al-40Si-5Fe coating was carried out at 330℃,which promoted the transformation of the coating structure and ultimately improved the high-temperature friction performance of the coating.The microstructures of the coatings before and after the heat treatment were observed using scanning electron microscopy and transmission electron microscopy.The results indicated that the spray coating structure was dense and presented a typical thermal spray coating structure.Owing to the difference in cooling rate,there was a significant difference in the upper and lower microstructure of a single spread.The upper part of a single spread consisted of a primary Si phase and an Al/Si eutectic phase,while the lower part consisted of an incomplete amorphous structure.The average size of the primary Si phase in the sprayed coating is approximately 200 nm.During the 330℃heat treatment process,thermal activation energy promoted the fusion and growth of the Si phase.The form

关 键 词：超音速等离子喷涂 铝硅合金涂层 时效处理 高温摩擦学性能 

分 类 号：TG156[金属学及工艺—热处理]