Design and testing of a cryogenic indentation apparatus.

A modularized cryogenic indentation apparatus was designed and created to study the deformation mechanisms and mechanical properties of materials at low temperatures. The indentation process is actuated by piezoelectric stack and flexure hinge, and the entire mechanical module is kept inside the vacuum chamber to prevent the occurrence of ice. Numerous issues including the effects of the application of cooling module and processes to diminish the temperature effect on the indentation tip were addressed. Several influential factors during temperature indentation were discussed. Tests on calibration specimen demonstrated the feasibility of the apparatus. Monocrystalline silicon and copper were tested using the current apparatus at temperatures ranging from room temperature to 150 K to show its main functions and usability.