6061-7075异种铝合金搅拌摩擦焊接件表面整体陶瓷防护膜的制备

Preparation of Overall Ceramic Coating on 6061-7075 Dissimilar Aluminum Alloy Friction Stir Welded Parts

通过微弧氧化处理,使6061与7075铝合金的搅拌摩擦焊接件(连接件)被一层陶瓷膜整体包裹,通过扫描电镜(SEM)、能谱(EDS)、X射线衍射(XRD)和电化学工作站等分析了母材和焊缝区表面膜层的形貌和成分,并基于检测结果推导了整体陶瓷膜的生长机制。结果表明:整体微弧氧化后,连接件表面的膜层是致密的;6061和7075表面膜主要成分为α-Al_(2)O_(3)、γ-Al_(2)O_(3)和少量的Al_(2)SiO_(5),而焊缝区则主要由α-Al_(2)O_(3)和γ-Al_(2)O_(3)组成;微弧氧化降低了连接件不同区域间的腐蚀电位差,显著提高了连接件整体的耐蚀性。

Through micro-arc oxidation treatment,the friction stir welded parts(connectors)of 6061 and 7075 aluminum alloys were integrally wrapped by a layer of ceramic film.Scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffraction(XRD)and electrochemical workstation were used to analyze the morphology and composition of the surface film on the base metal and weld zone,and based on the detection results,the growth mechanism of the monolithic ceramic film was deduced.The results showed that the film layer on the surface of the connector was dense after the overall micro-arc oxidation.The main components of the film on the surface 6061 and 7075 wereα-Al_(2)O_(3),γ-Al_(2)O_(3)and a small amount of Al_(2)SiO_(5),while the weld zone was mainly composed ofα-Al_(2)O_(3)andγ-Al_(2)O_(3).Micro-arc oxidation reduced the corrosion potential difference between different regions of the connector and significantly improved the overall corrosion resistance of the connector.