A RUAG Australia project has proven Supersonic Particle Deposition (SPD) repairs successfully restore both the lost structural integrity and the load carrying capacity of aircraft wing panels.
Neil Matthews, senior manager Research and Technology, RUAG Australia, and Professor Rhys Jones, Head Centre of Expertise Structural Mechanics, Department of Mechanical and Aerospace Engineering, Monash University have won the ‘Best Written Paper’ Award in Additive Manufacturing, at the 17th Australian International Aerospace Congress, held at the recent Avalon Airshow.
“Corrosion related issues represent up to $228m annual spend on ADF aircraft”
Their success in investigating and proving the viability of Supersonic Particle Deposition (SPD) repair technology for structural components, in this case corroded wing skins on operational aircraft, provides a more positive outlook for air forces, in terms of continued platform performance and improved cost-savings on maintenance budgets, according to a release issued by the company.
“Testing was performed on operational aircraft replicated structure using operational flight load spectra,” Matthews said. “The outstanding results are specifically interesting with regards to legacy aircraft, as corrosion related issues represent up to $228 million annual spend on ADF aircraft, and at least 31 per cent of the US Air Force’s annual maintenance costs.”
He added these sums were not expected to scale down as air forces the world over are operating aircraft longer due to budget constraints.
The paper demonstrates that SPD repairs restore integrity for external patch repairs to skin corrosion, for embedded scarf repairs, and for external patch repairs to inhibit intergranular cracking (IGC). In fact, analysis reveals that SPD repairs on compression surfaces where there is up to a 50 per cent loss of material between the risers can essentially restore the load carrying capacity of the wing, even in the case of Stress Corrosion Cracking (SCC) in the risers.
Matthews and Jones are considered world leaders on the subject of SPD (also referred to as Cold Spray), a technology in which metal powder particles are accelerated to supersonic speeds in a high pressure expanded gas flow and impact a solid surface with sufficient energy to cause plastic deformation and bonding with the underlying material.