Plastic deformation and fracture mechanisms of a novel Al/Mg bimetal composite at cryogenic temperatures
Publication Name
Journal of Materials Research and Technology
Abstract
Examining the cryogenic-temperature characteristics of composites is imperative for ensuring the sustained functionality of their components in environments with cryogenic temperatures. The plastic deformation and fracture mechanisms of a novel Al/Mg bimetal composite (5052/AZ31B alloys bimetal composite) fabricated by the corrugated and flat rolling were investigated at cryogenic temperatures in this study. A mixture-law constitutive model was established to describe the flow behaviour of each constitute alloy of bimetal composite based on the stress-strain relationships obtained from cryogenic tensile tests, which were performed on a universal testing machine equipped with a liquid nitrogen in the temperatures of −180 °C, −80 °C and room temperature (RT) at the strain rate of 0.001 s−1. It is found that the elastic modulus of the 5052/AZ31B bimetal composite experiences minimal impact at lower temperatures, whereas the flow stress shows an increase with decreasing temperature. The AZ31B layer exhibits a quasi-disintegrated brittle fracture and reduced elongation to failure, leading to premature fracture, while the 5052 layer demonstrates a mixed tough-brittle fracture and increased plasticity, resulting in a two-stage fracture process with AZ31B fracturing earlier at the temperature of −180 °C. These findings align with finite element simulations, validating the intricate interplay between bimetal composite properties and cryogenic temperature in influencing fracture behaviour.
Open Access Status
This publication may be available as open access
Volume
30
First Page
3297
Last Page
3307
Funding Number
52105418
Funding Sponsor
National Natural Science Foundation of China