Tests on slip resistant behaviour of aluminium alloy-stainless steel faying surfaces

Abstract

Aluminium alloy-stainless steel structures combine the benefits of high strength-to-weight ratios of aluminium alloys with the excellent ductility of stainless steels. In order to explore the slip resistant aluminium alloy-stainless steel connections, this paper emphasized the surface characteristics and slip resistance of various surface treatments on aluminium alloy and stainless steel plates. Six applicable treatment methods for aluminium alloy-stainless steel slip resistant faying surfaces were experimentally investigated with specifications for the key parameters explored for the treatment procedures. The feasibility of two novel surface treatment methods on aluminium alloy and stainless steel surfaces was evaluated by material tests and the inspection for coatings. The key characteristics of the treated surfaces were comprehensively tested, including the 3D scanned surface topography, measured hardness and roughness. The relationships between the material type, hardness and roughness values under various surface treatments were discussed, which suggested the specific provisions for slip resistant connections in aluminium alloy-stainless steel structures were required. Friction tests of 18 shear connections were conducted to study the friction coefficients of different materials and surface treatments. The impactions of the surface characteristics on slip resistant behaviours of the treated surfaces were analysed. The roughness of the stainless steel surfaces and the hardness of the aluminium alloy surfaces influence the friction coefficients of the examined connections. Through comparative studies, the arc spraying and supersonic cold spraying, as two novel surface treatments, are suggested for the faying surfaces of aluminium alloy-stainless steel shear connections relying on their remarkably high friction coefficients. While the grit blasting and wire brushing also presented pronounced slip resistant capacities among the four examined mechanical surface treatments.