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

作　　者：娄云天 余志豪 常卫卫 钱鸿昌 郭达伟 张达威 LOU Yuntian;YU Zhihao;CHANG Weiwei;QIAN Hongchang;Guo Dawei;ZHANG Dawei(Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;Shunde Innovation School,University of Science and Technology Beijing,Guangdong Foshan 528399,China;IDQ Science and Technology Development(Hengqin,Guangdong)Co.,Ltd.,Guangdong Zhuhai 519060,China)

机构地区：[1]北京科技大学新材料技术研究院,北京100083 [2]北京科技大学顺德创新学院,广东佛山528399 [3]广东横琴澳质研科技发展有限公司,广东珠海519060

出　　处：《表面技术》2025年第8期84-95,共12页Surface Technology

基　　金：广东省基础与应用基础研究基金(2021B1515130009)。

摘　　要：目的研究增材摩擦搅拌沉积(Additive Friction Stir Deposition,AFSD)工艺及T6热处理对AA6061铝合金多层沉积样件不同层位金属间化合物分布及其耐蚀性能的影响。方法采用AFSD工艺制备AA6061铝合金沉积试样,并对其进行T6热处理。分别从上、中、下层取样,结合扫描电子显微镜(SEM)、能谱分析(EDS)、和ImageJ图像处理,研究各层析出相的种类与分布特征。通过电化学阻抗谱(EIS)分析腐蚀行为,并辅以XRD与CLSM等手段表征腐蚀产物和腐蚀坑形貌。结果固态增材试样和热处理后的试样内部主要包含Mg2Si和AlFeSi两种金属间化合物。与母材棒相比,AA6061铝合金增材试样内部金属间化合物尺寸明显细化,分布更加均匀且数量显著增加。热处理后金属间化合物的数量相比热处理前有所减少,但仍多于母材棒中的数量。由于靠下的沉积层中所受热循环次数较多,析出的金属间化合物数量明显多于上层。电化学测试结果表明,热处理前后试样的电化学阻抗结果呈现出上层>中层>下层的规律性分布。热处理导致部分金属间化合物重新融入固溶体相,热处理试样的耐蚀性明显好于热处理前的增材试样。腐蚀形貌分析也表明,下层沉积层经过浸泡实验后点腐蚀最为严重。结论AFSD试样中Mg2Si和Al Fe Si析出相从上层到下层分布不均,且下层耐蚀性最差。T6热处理可减少析出相,提升耐蚀性。在实际应用中,应根据工况合理评估耐蚀性差异,优先使用T6热处理后的上层沉积区,还可结合表面防护涂层增强耐蚀能力。研究突破了以往单一性能研究的局限,创新性地从金属间化合物分布、电化学阻抗和腐蚀形貌等多个维度系统地研究了热处理前后增材试样的性能变化,以上研究结果为进一步理解AFSD固态增材铝合金腐蚀行为、开展相关的耐蚀性调控提供了数据支撑。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(C

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 

分 类 号：TG174[金属学及工艺—金属表面处理]