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Effect of High‐Pressure Torsion on the Thermal and Mechanical Properties of La 62 Cu 12 Ni 12 Al 14 Bulk Metallic Glass
Author(s) -
Guo Jing,
Joo SooHyun,
Pi Donghai,
Kim Wooyeol,
Song Yuepeng,
Kim Hyoung Seop,
Zhang Xiaohui,
Kong Dan
Publication year - 2019
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201800918
Subject(s) - materials science , amorphous metal , composite material , crystallization , hydrostatic pressure , brittleness , torsion (gastropod) , softening , shear band , shear (geology) , thermal expansion , glass transition , plasticity , metallurgy , thermodynamics , alloy , medicine , physics , surgery , polymer
Even though bulk metallic glasses (BMGs) are generally brittle, they receive large plastic deformations of over 1000% shear strain without fracturing through the application of combined shear and hydrostatic stresses. In this study, the effects of the severe plastic deformation by high‐pressure torsion (HPT) on the thermal and mechanical properties of La 62 Cu 12 Ni 12 Al 14 BMG are investigated. Crystallization is not detected during the HPT processes with 5, 15, and 30 revolutions. However, increase in glass transition temperature, crystallization temperature, fracture strength, and fracture strain, and decrease in the coefficient of thermal expansion and hardness due to the HPT process are found. These changes in the properties are attributable to the increased free volume that results from the rejuvenated structure in the HPT‐processed BMG. In addition, the fracture in the HPT‐processed La 62 Cu 12 Ni 12 Al 14 BMG proceeds through a softening mechanism in the microscale region.