1995 Volume 44 Issue 497 Pages 243-248
Since a thermocouple can be attached on a specimen, it is possible to measure the temperature of a moving point such as a surface of deforming body. The response of thermocouple is dependent on the junction volume of thermocouple because the usual thermocouple is a welded-bead type. It is considered that the response in a compression test is improved by use of a contact surface between a specimen and a tool as a thermocouple. However, since the diameter of specimen or tool is much larger than a usual thermocouple diameter, it is also important to examine the influence of heat loss on the accuracy of measurement.
This paper describes the influence of heat loss on the temperature of the contact surface during an elastic-plastic deformation. The accuracy was examined by comparing the experimental results with the numerical ones in which the heat conduction and heat transfer are taken into consideration. In the experiment a copper specimen and a stainless steel tool were used under a range of strain rate from 4×10-4s-1 to 3×10-2s-1.
The experimental results obtained are in good agreement with the numerical ones and also with the experimental ones obtained using a usual thermocouple. Therefore, it is clear that the temperature measurement method utilizing the contact surface as a thermocouple is an effective one.
