Influences of Temperature and Strain Rate on Mechanical Behavior of a Cu₄₅Zr₄₅Al₅Ag₅ Bulk Glassy Alloy

Abstract

Since the invention of bulk glassy alloys, a number of studies have been performed at ambient temperatures or above. However, little is known about mechanical properties of bulk glassy alloys at cryogenic temperatures. In this study, we investigated the effects of temperature and strain rate on the mechanical properties of a Cu₄₅Zr₄₅Al₅Ag₅ bulk glassy alloy fabricated by high pressure die casting methods. Compression tests were performed for the Cu₄₅Zr₄₅Al₅Ag₅ bulk glassy alloy rods with a diameter of 3 mm at temperatures of 298, 223, 173 and 77 K and at strain rates from 5×10⁻⁵ to 5×10⁻³ s⁻¹. It is found that the maximum compressive stress and plastic strain to failure increase monotonically with decreasing testing temperature. Multiple shear bands are observed on the side surface of the specimen deformed plastically at cryogenic temperatures. The maximum compressive stress and plastic strain are almost independent of strain rate. The reason for the changes in the maximum compressive stress and plastic strain with temperature and strain rate is discussed.