Aerospace Al alloy cold spray coating performance under fatigue and corrosion environments

冷喷涂是一种可以认为是添加剂修复的修复过程，金属粉末颗粒在载气中，在相对较低的温度下高速撞击，因此修复的表面层是通过极端变形而不是熔化和凝固形成的。基体和新涂层之间不断变化的显微组织和残余应力状态意味着CS结构目前还没有被用于高应力位置，因为它们的力学性能还没有得到很好的了解。需要更好地了解层状系统中的微观力学过程如何控制疲劳和腐蚀相互作用。这是空中客车运营公司与考文垂大学合作支持的一个大型研究项目的一部分，该项目将使用先进的微结构表征技术（SEM， EBSD， EDX， TEM和x射线CT）来分析CS微结构和缺陷分布的演变。并将研究现场实验力学方法（例如DIC和EC-AFM），以评估疲劳载荷和腐蚀服务条件下的应变演变和腐蚀过程。

Cold spray is a repair process that can be considered an additive repair process, whereby metal powder particles are impacted at high speed in a carrier gas, at relatively low temperatures, so the repaired surface layer is formed by extreme deformation rather than melting and solidification. The evolving microstructures and the residual stress states between the substrate and new coating layer mean CS structures are not currently used in highly stressed locations as their mechanical performance is not well understood. A better understanding of how the micromechanical processes in this layered system controlling fatigue and corrosion interactions is needed. This is part of a larger research project supported by Airbus Operations, in collaboration with Coventry UniversityThis project will use advanced microstructural characterization techniques (SEM, EBSD, EDX, TEM and X-ray CT) to analyse the evolution of the CS microstructure and defect distributions, and will also investigate full field experimental mechanics approaches (e.g. DIC and EC-AFM) to evaluate strain evolution and corrosion processes under fatigue loading and in the presence of corrosion service conditions.