Investigation of the Formability of Cryogenic Rolled AA6061 and Its Improvement Using Artificial Aging Treatment

Abstract

Cryogenic rolling is one of the essential severe plastic deformation processes to manufacture high-strength aluminum sheets with excellent formability limits. The present work characterizes the formability of AA6061 for cryogenic rolling before and after artificial aging. Nakajima method based on ISO standard is used to measure formability. Samples are aged in the range of 100 °C to 150 °C. Artificial aging at 150 °C is found to be the optimum temperature for achieving a good combination of strength and formability. Over the course of artificial aging, strength improved up to 40%, where the original value of 250 MPa for cryo-rolled condition increased to 350 MPa after 50 h of aging at 150 °C, and the formability of the cryo-rolled sample improved especially for multi-axial forming condition.

Keywords

• cryogenic rolling
• AA6061
• forming limit diagram
• artificial aging
• mechanical properties