A tensile property measuring system for miniaturized samples from 300 K to 70 K based on pulse tube cryocooler

Abstract

With the rapid development and wide application of cryogenic, superconducting and space technologies in engineering fields, measurements of the mechanical properties especially the tensile properties of small-sized samples at cryogenic temperatures are more and more important. In this study, a tensile property measuring system for miniaturized samples was designed and built, where the samples can be measured from 300 K to 70 K with a resolution of 0.1 K. The cryogenic environment was provided by a pulse tube cryocooler. The force load applied to the sample was up to 10 N with a resolution of 0.001 N. The structure of the cryogenic system and sample holders were specially designed for miniaturized samples. A control and automatic data acquisition system was used to control and acquire data from all devices of the instrument. The simulations of the stretching part under load at cryogenic temperature were performed to ensure the measurement accuracy and reliability. To verify the performance and accuracy of the system, the tensile properties of two kinds of fine high-purity copper wires were measured at both 77 K and 300 K. The tensile measurement results were discussed and the measurement uncertainty of the system was analyzed. With different clamps more kinds of mechanical measurements of miniaturized samples can be carried out on this system.