Experimental study on tensile plasticity of light metal engineering alloys for automotive application

This report is a summation of the research conducted on readily available Aluminum Alloys widely used in automotive manufacturing. The research conducted at Wayne State University was part of a project involving a new technology being developed for a faster and a more efficient forming of automotive components. It specifically deals with engineering alloys to be used for hot metal gas forming. Experiments were conducted at elevated temperatures with uniaxial tensile loading at varying temperatures and strain rate.; The primary area of concentration was to analyze the flow stresses as a function of strain, strain rate and temperature. The results were used to select suitable materials and the corresponding optimal forming window of temperature and stain rate for HMGF.; Several aluminum alloys were tested at elevated temperatures (350-550°C) and at varying strain rates (0.0001s-1 to 1.0s-1). It was observed that AA5083 gave very good elongation required for HMGF, and AA6061-T6 showed good formability at 450°C-500°C and at high strain rates (0.1-1s-1), with relatively low flow stresses as compared with AA5083. In some cases a higher strain rate gave a higher total elongation. This unusual phenomenon is explained due to dynamic recrystallization and it is beneficial for automotive production. The samples from extruded tubes with lower thickness showed better formability than that of higher thickness, due to the much finer grain size of the thin-wall tubes.