Managing corrosion through an enhanced repair procedure of aerospace wing skin parts using cold spray technology

Corrosion around fasteners in aluminium wing skin components remains a persistent maintenance challenge for the aerospace sector, often leading to costly downtime. The standard repair involves mechanical grinding, epoxy resin application, and overpainting. Unfortunately, this repair is proving to be insufficient, with reports of corrosion damage returning sooner than anticipated. With industrial guidance from aerospace original equipment manufacturers (OEM) and maintenance, repair and overhaul (MRO) companies, a cold spray-based repair method was developed using aluminium 7075 alloy with ceramic additives. The process achieved dense, well-adhered coatings using nitrogen as the process gas and parameters suitable for a low-pressure cold spray system. Comparative testing against conventional epoxy repairs demonstrated superior mechanical and environmental performance. The cold spray repair exhibited enhanced tensile strength, while the epoxy-based samples showed early brittle fracture. Salt-spray corrosion testing further highlighted the benefits of cold spray repair: epoxy repairs delaminated within 150 hours, whereas cold-sprayed samples maintained structural integrity beyond this exposure. These findings form initial validation of cold spray as a viable alternative for corrosion-resistant repair.