表面技术2025，Vol.54Issue(17)：18-32,15.DOI:10.16490/j.cnki.issn.1001-3660.2025.17.002
微弧氧化涂层对铝合金疲劳性能影响与改进途径研究进展
Research Progress on Influence of Micro-arc Oxidation Coatings on Fatigue Property of Aluminum Alloys and Improvement Approaches
摘要
Abstract
Aluminum(Al)alloys are key lightweight materials for automobiles and spacecraft,and are often used in rocket tanks,automobiles,and satellite casings.Notably,the low surface hardness,poor corrosion resistance and aluminum-thermal reaction of Al alloys seriously threaten the service safety of the carrier equipment.Aiming at the issue,it is necessary to apply a protective coating to the Al alloy surface.Micro-arc oxidation(MAO)coating is a protective coating that grows in situ on the substrate surface in the environmentally friendly electrolyte,possessing excellent wear resistance,corrosion resistance,heat resistance and insulation properties.Moreover,the coating preparation process is simple,and the sample shape is widely applicable.Thus,MAO technology has great application prospects in the manufacturing field of'air-space-ground'equipment. The heat generated by micro-arc discharge leads to the melting of the substrate surface and the formation of oxides is dominated by substrate elements.Meanwhile,the high temperature and pressure produced by micro-arc discharge causes the molten oxide to extrude from the discharge channel,which is encountered with the electrolyte and adhered to the substrate surface.In the MAO process,the grooves formed by the melting of the substrate surface are called overgrowth zones.The discharge channel not filled with molten oxide forms micropores.Mismatch stress is induced by temperature gradient and thermal expansion coefficient difference between the coating and the substrate.Mismatch stress greater than coating strength leads to crack formation,and the residual mismatch stress is called residual stress.The generation of intrinsic defects(micro-defects and residual stress)is the common problem of metals treated by MAO. Ceramic coatings with intrinsic defects exhibit hard and brittle properties and defect sensitivity,which causes fatigue deterioration of the substrate.Large-sized micropores and cracks,residual tensile stress,and rough interface impair the fatigue property of the substrate.Stress concentration exists in micropore,crack,interfacial defect and rough surface,inducing crack initiation.The distribution of the coating and residual stress affects the crack propagation rate.In addition,the microstructure of interfacial substrate is another important factor affecting the fatigue life of MAO coated Al alloys.Notably,the effects of micropores,cracks,interfacial defects(overgrowth and surface defects),residual stress and external cyclic stress on fatigue life are coupled.The inhibition of stress concentration at rough interface by interfacial residual compressive stress and the change of crack initiation location induced by external cyclic stress are important factors that the MAO coating differently affects the high and low cycle fatigue life of the substrate. Studies reveal that the synergistic coupling effects of the coating intrinsic defects under three specific conditions induce fatigue degradation of the substrate.Residual tensile stress and serious overgrowth of the interface are one of the key factors for the MAO coating induced high cycle fatigue degradation of the substrate.The coupling effect of the coating large-sized micropores and cracks,residual tensile stress adjacent to the substrate,and severe interfacial overgrowth leads to the high cycle fatigue degradation of the substrate.Then,the MAO coating large-sized micropores and cracks,as well as severe overgrowth of the interface,contribute to low cycle fatigue degradation of the substrate.Based on the concept of synergistically regulating intrinsic defects and substrate surface microstructure to reduce coating defects,mitigate the coupling effects of residual stress and defects,and inhibit the propagation of coating cracks into the substrate,a fatigue optimization methodology is proposed in this study.Multi-dimensional regulation integrating substrate pretreatment,process parameter optimization,and post-coating treatment is a feasible method to enhance the fatigue life of the MAO coated Al alloys.The results provide new insights and solutions for the bottleneck problem of poor fatigue property and the difficulty to predict fatigue life in the application of MAO technology for strengthening lightweight materials.关键词
铝合金/微弧氧化/内禀缺陷/耦合机制/疲劳Key words
aluminum alloys/micro-arc oxidation/intrinsic defects/coupling mechanism/fatigue分类
矿业与冶金引用本文复制引用
戴卫兵,张册,郭辰光,黄文超,岳海涛,张建卓..微弧氧化涂层对铝合金疲劳性能影响与改进途径研究进展[J].表面技术,2025,54(17):18-32,15.基金项目
中国博士后科学基金资助项目(2023TQ0145) （2023TQ0145）
辽宁省教育厅基金青年项目(JYTQN2023195) （JYTQN2023195）
辽宁省自然基金联合计划项目(20240339) （20240339）
2024年辽宁省教育厅基本科研项目-科技创新团队项目(LJ222410147020)China Postdoctoral Science Foundation(2023TQ0145) （LJ222410147020）
Scientific Study Project for Institutes of Higher Learning,Liaoning Province(JYTQN2023195) （JYTQN2023195）
Liaoning Provincial Natural Science Foundation Joint Program Project(20240339) （20240339）
2024 Liaoning Provincial Department of Education Basic Research Project-Science and Technology Innovation Team Project(LJ222410147020) （LJ222410147020）
