表面技术2025，Vol.54Issue(8)：84-95,12.DOI:10.16490/j.cnki.issn.1001-3660.2025.08.007
搅拌摩擦沉积固态增材AA6061铝合金不同沉积层腐蚀行为研究
Corrosion Behaviour of Different Deposition Layers in AA6061 Aluminum Alloy Produced via Additive Friction Stir Deposition
摘要
Abstract
Solid-state additive manufacturing is an advanced fabrication technology that does not rely on material melting.It primarily includes techniques such as ultrasonic additive manufacturing,cold spray additive manufacturing,and additive friction stir deposition(AFSD).Among these,AFSD combines the principles of friction stirring with continuous material feeding to create a unique solid-state and low-temperature additive process.Compared with conventional fusion-based additive manufacturing,the low thermal input and extensive plastic deformation in AFSD promote the formation of fine equiaxed microstructures and defect-free interiors,thereby significantly enhancing the mechanical properties of the fabricated parts.In addition,AFSD can be carried out in open environments and is easily scalable,making it particularly suitable for the fabrication and repair of large-scale components.At present,AFSD remains the only metal additive manufacturing technique capable of achieving mechanical properties comparable to forging.In recent years,the AFSD process has become increasingly mature and has been widely applied in the solid-state additive manufacturing of aluminum alloys,especially gaining significant attention in studies on 6xxx series alloys.This study investigates the effects of additive friction stir deposition(AFSD)and subsequent T6 heat treatment on the distribution of intermetallic compounds and the corrosion resistance across different layers of multilayer-deposited AA6061 aluminum alloy.AA6061 aluminum alloy coupons are fabricated using the AFSD process and then subject to T6 heat treatment.Samples are taken from the upper,middle,and lower layers.The type and distribution of intermetallic precipitates are analyzed by scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS),and ImageJ image processing.Corrosion behavior is characterized by electrochemical impedance spectroscopy(EIS),while corrosion products and pit morphologies are examined by X-ray diffraction(XRD)and confocal laser scanning microscopy(CLSM).The as-deposited and heat-treated samples mainly contain Mg2Si and AlFeSi intermetallic compounds.Compared with the base metal,the intermetallic phases in the AFSD samples are significantly refined,more uniformly distributed,and markedly increased in number.After heat treatment,the amount of intermetallic compounds is reduced but remains higher than that in the base metal.Due to the greater thermal cycling experienced by the lower layers during deposition,a larger number of precipitates are observed in these regions.Electrochemical tests reveal a layer-dependent corrosion resistance,following the trend upper＞middle＞lower.Heat-treated samples exhibit improved corrosion resistance owing to the partial dissolution of intermetallic back into the solid solution.Corrosion morphology also confirms that the lower layers show the most severe pitting after immersion.The Mg2Si and AlFeSi precipitates in AFSD samples exhibit non-uniform distribution along the build direction,with the lower layers showing the poorest corrosion resistance.T6 heat treatment reduces the amount of precipitates and enhances corrosion performance.In practical applications,corrosion resistance variation should be carefully evaluated based on service conditions,with preference given to the upper heat-treated regions.Additional surface coatings may further enhance corrosion protection.This work goes beyond previous studies that focus on single performance metrics,offering a comprehensive investigation into the evolution of intermetallic,electrochemical behavior,and corrosion morphology before and after heat treatment.The findings provide valuable insights for understanding corrosion mechanisms and optimizing corrosion resistance in AFSD-processed aluminum alloys.关键词
搅拌摩擦沉积固态增材/铝合金/金属间化合物/腐蚀行为Key words
additive friction stir deposition/aluminum alloy/intermetallic compound/corrosion behavior分类
矿业与冶金引用本文复制引用
娄云天,余志豪,常卫卫,钱鸿昌,郭达伟,张达威..搅拌摩擦沉积固态增材AA6061铝合金不同沉积层腐蚀行为研究[J].表面技术,2025,54(8):84-95,12.基金项目
广东省基础与应用基础研究基金(2021B1515130009)Guangdong Basic and Applied Basic Research Foundation(2021B1515130009) （2021B1515130009）
