Deposition of AA6082-T6 over AA2024-T3 by friction surfacing - Mechanical and wear characterization

Friction Surfacing is a solid state coating technique with applications in the rehabilitation of worn parts, hardfacing or corrosion protection. It is suitable to process aluminium alloys as it does not require the fusion of neither the coating nor the substrate, relying on a solid state diffusion bonding mechanism. The present study addresses the use of friction surfacing to deposit AA6082-T6 on AA2024-T3, with emphasis on tensile, bending and wear characterization. The thermo-mechanical transformations experienced by the materials during processing were also investigated. Sound aluminium coatings were produced featuring a sound bonding with no porosity or intermetallic formation at the interface. The coated specimens present an ultimate tensile strength 25% lower than the substrate AA 2024-T3 base material while the strain at break was improved in 42%. Although the coating edges were seen to be prone to delamination, coating fracture did not precede substrate fracture. An improved coating wear performance was observed due to the microstructural features identified under SEM, namely a micrometric sub-grain structure.