2018 Volume 59 Issue 688 Pages 78-83
An experimental procedure for the hot compression test for Ni-based alloy was proposed and evaluated in order to obtain an appropriate stress-strain curve for numerical analysis. The effect of various parameters, i.e., top and bottom shapes of specimen, lubricant and jig/tool, on the deformation tendency was systematically studied. Ni-based alloy (CMSX-4), which has a higher strength than the specimen, was used as die for preventing temperature gradient. This improved the uniformity of temperature distribution in the specimen. The combination of a specimen having concentric circles on the end surface and a glass sheet as lubricant was the most appropriate to gain stable and low-friction condition of the specimen end. The proposed procedure of the hot compression test is applicable for the temperature range of 1173－1423 K and strain rate range of 0.01－5 s-1. The effectiveness of the obtained stress-strain curve was discussed from the viewpoint of the value and tendency of characteristic features observed in the flow stress curve. The maximum stress exhibited normal temperature and strain rate dependence. Related activation energy for deformation was similar in value to those in other reports.