Enhancement in Strength and Ductility of Al-Mg-Si Alloy by Cryorolling followed by Warm Rolling

Abstract

The effect of cryorolling followed by warm rolling (CR+WR) on strength and ductility of Al- Mg-Si alloys has been studied in the present work. Ultrafine grained Al 6063 alloy was developed through cryorolling up to 80% and warm rolling up to 50% at 200 °C followed by ageing at 100 °C for 22 hr. It is compared with the material processed through cryorolling followed by low temperature ageing. By implementing this new approach, simultaneous improvement in strength (290 MPa) and ductility (15%) was achieved in Al 6063 alloys. The microstructure and precipitate evolution were characterized by Optical microscope, Electron back scattered diffraction (EBSD) and Transmission electron microscope (TEM) techniques. The ultrafine grain structure with 150-300 nm was observed in CR+WR sample. Mechanical properties were studied by performing hardness and tensile testing at room temperature. Strength and ductility of CR+WR samples are found to be superior to CR sample after peak ageing treatment.