Effects of material and processing conditions upon ring calibration curves

Abstract The ring test has been established as a method of determining the shear friction factor at the die-workpiece interface. It has been reported that ring calibration curves are dependent upon the strain, strain rate and thermal and mechanical characteristics of the material as well as the ring geometry. This paper examines the effects of some of these variables upon ring calibration curves using the rigid viscoplastic finite element program ALPID and experimental data. Three materials were studied, namely aluminum alloy 2024-O, Ti-6wt.%Al-4wt.%V and Ti-48at.%Al-1at.%V. ALPID analysis indicates that the calibration curves are dependent upon the ring geometry and strain rate sensitivity of the material. The inner-surface profile of compressed rings is dependent upon the ring geometry, percentage reduction in height, and shear friction factor. Compression tests on aluminum alloy 2024-O rings of 6:3:1 and 6:3:2 geometry and on aluminum alloy 1100-O rings of 6:3:2 geometry were conducted to evaluate two lubricants using the ALPID results.