Effect of Aging on Hardness in the Ring Compression Tests Using Experimental and Finite Element Investigations

摘要

The heterogeneity of hardness distribution in a ring compression test was investigated in the present research. Rings of size 24 mm o.d. and 12 mm hole were machined to a height of 8 mm. All the samples were solutionized at a temperature of 502℃. The solutionized samples were grouped into three sets and each group was aged for 9,13, and 18 h, respectively. Each group of samples was upset between rigid dies to different levels of strain. The ring compression tests were modeled using a finite element software package and were upset to identical strain levels as done in the experiments for all the aging conditions. The hardness at different zones in the upset ring was measured using Vickers indenter and the hardness was also predicted from the relation between effective strain distribution and Vickers hardness. The predicted results were in close agreement with the experimental results. It can be explained that the hardness in the upset ring is not uniform throughout the ring specimen and will vary near the surface, along the neutral plane, at the bulge head of the ring, and also with aging condition.