High Temperature Deformation in the Amorphous or Partially Crystallized Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5 Bulk Metallic Glass

Abstract

The high temperature deformation of the Zr41.2Ti12.5Cu13.8Ni10Be22.5 bulk metallic glass (BMG) is studied in the supercooled liquid region. Both fully amorphous and partially crystallized states are investigated. In the studied experimental domain, the amorphous alloy exhibits a Newtonian behavior at high temperature and/or low strain rate whereas a transition to non-Newtonian behavior is observed when the temperature is decreased and/or the strain rate is increased. In the Newtonian domain, the dependency of the viscosity upon temperature can be described by an Arrhénius law. As far as the as-received alloy is maintained at high temperature for which phase separation and primary crystallisation is expected, the flow stress continuously increases, which is at least partly attributed to a change in the residual amorphous phase.

Oxidation and crystallization of Zr-based bulk metallic glass due to machining

“…The dispersion of nano-crystalline particles with an amorphous structure increases the elastic modulus [5], hardness [5][6][7], and tensile strength [8]. Wang et al [9] quantified the effect of crystallization on hardening in high temperature deformation of BMG. Zhang et al [10] observed that, after full crystallization of the Zr 48 Nb 8 Cu 14 Ni 12 Be 18 BMG, the material demonstrated a 40% increase in hardness, 20% increase in elastic constant, 6.7% increase in thermal expansion coefficient, and 1.6% increase in density.…”

Indentation creep behavior of a Zr-based bulk metallic glass

“…Viscosity vs. strain-rate at different temperatures. other compositions of Zr-based bulk metallic glasses [3,19]. Q = 432, 410 and 375 kJ/mol have been obtained by compression tests for the compositions of Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 [19], Zr 55 Cu 30 Al 10 Ni 5 [3] and Zr 65 Cu 15 Al 10 Ni 10 [3], respectively.…”

AMORHIZATION AND LIQUID STATE SEPARATION IN Ni80-2xCuxFexP20 ALLOYS

“…Such composites can be made by introducing the particles ex situ prior to casting [5][6][7], or by the formation of the crystalline phase in situ. The latter can be carried out by the crystallization of the amorphous matrix or the formation of the crystalline phase during casting [8][9][10][11][12][13]. It is also possible to use liquid immiscible alloys for this purpose [12][13][14].…”