Mechanical properties of a Ni 60Pd 20P 17B 3 bulk glassy alloy at cryogenic temperatures

Abstract

Little is known about mechanical properties of bulk glassy alloys (BGAs) at cryogenic temperatures. In this study, we investigated the effects of temperature and strain rate on the mechanical properties of a Ni 60Pd 20P 17B 3 BGA. Compression tests were performed at temperatures of 295, 223, 173 and 77 K and at strain rates from 5 × 10 −5 to 5 × 10 −3 s −1. Measurements of the elastic parameters were also made at temperatures from 91 to 371 K. It is found that both the maximum compressive stress and plastic strain to failure increase with decreasing testing temperature. The Young and shear moduli, and Debye temperature monotonically increase with decreasing temperature, while Poisson’s ratio decreases, indicating that the BGA becomes rigid and the effective atomic distance decreases at cryogenic temperatures. The mechanism reflecting the changes in the maximum compressive stress and plastic strain with temperature is discussed.