Abstract
A hard tension/compression tester has been developed for a high temperature microscope and built into a side-entry specimen holder, without any interference of the functional features of the microscope. The noticeable advantage of the microscope with the tension/compression tester lies in the cabability of the in-situ observation of metallurgical phenomena at any stage of the load-elongation curves at elevated temperatures.
The specific features are as follows:
i) The standard specimen for tension/compression test is 5 mm in gauge length, 2 mm in width and 0.5∼1 mm in thickness.
ii) The maximum load is 100 kg.
iii) The maximum stroke is 5 mm.
iv) The cross head displacement speed is set in six steps, 0.025, 0.020, 0.015, 0.010, 0.005 and 0.0025 mm/s during the elongation of specimens, independent of the load applied.
v) The spring constant of the tester is estimated to be larger than 700 kg/mm or 7×106 N/m.
This tester was successfully applied to the observing and recording of metallurgical phenomena such as the formation of strain-induced martensites at 250°C in Fe-22%Ni alloy and the giant slip bands during the serrated elongation at 450°C in a Cu-10 at%Al single crystal.
