Deformation behaviors of Al–4.5 mass% alloy in semi solid state

Abstract

Deformation behaviors of Al–4.5mass%Cu alloys in semi solid state were investigated with tensile tests and their in situ observation. Deformation behaviors were classified into six stages (from stage I to stage VI, stage I was the lowest temperature range of semi solid state) by mechanical properties, morphologies of fracture surfaces and in situ observations during deformation. In the stages occured hearing (stage V and stage VI), the deformation was caused by flow of liquid phase. Therefore, the elongation could not be evaluated as the ductility of material in these stages. The range of temperature appearing the hot tearing was restricted to narrow temperature range in semi solid state, and was classified to stage II to stage IV. The tensile test method to research deformation behaviors of aluminum alloys in semi solid state with high accuracy was developed.