Al‐Based Amorphous Metallic Plastics

Abstract

A new class of Al-based metallic glasses is identified, which exhibits polymerlike thermoplastic formability near the boiling point of water. To satisfy the requirements for thermoplastic behavior, a series of AlSm-based metallic glasses are examined by Flash DSC to determine the glass transition temperature, T g . Viscosity measurements confirm that the T g values of the AlSm-based glasses are below 100 C. Bending and imprinting trials in boiling water demonstrate permanent deformation without the development of shear bands as required for thermoplastic behavior. Comparison of the thermoplastic formability index values indicates that the AlSm-based glasses exhibit behavior similar to that for common Fe-based metallic glasses. Kinetic measurements are used to evaluate the lifetime before the onset of crystallization. The AlSm-based glasses have a significant potential in the areas of electromechanical systems, micro-scale biomedical parts, nanorobots, and micromachines.

Microalloying effect in ternary Al-Sm-X (X = Ag, Au, Cu) metallic glasses studied by ab initio molecular dynamics

“…For example, ∼2 at% substitution of Ni or Y by La or Co in Al86Ni8Y6 increases the GFA of this alloy, as shown by Yang et al who synthesized experimentally Al-Ni-Y-Co-La MG with the size of approximately 1 mm [18]. Recently, Gao et al published a series of studies of minor alloying in Al-Sm-X alloys exploring their changes in key MG thermo-kinetic properties such as glass transition temperature, Tg, and crystallization temperature, Tx [19]. In this work we used this data and explored the ability of VP to correlate with the GFA of these alloys.…”

“…5(a). 𝑇 # and 𝑇 " were obtained from previous experimental measurements [19] and are listed in Table 1. These values are then used to determine Rc and the correlation between the Rc and the AIMD simulated ICO-like fraction is shown in Fig.…”

Combinatorial measurement of critical cooling rates in aluminum-base metallic glass forming alloys

“…Al-based metallic glasses are an important family of glass forming alloys with tremendous potential technical importance 43 . They generally exhibit high specific strength, high corrosion resistance, which are paired with other attractive attributes 43 , 44 . Their glass forming ability (GFA), however, is generally low, with largest reported critical casting thickness of ~ 1 mm 45 .…”

Metastable intermetallic phases in the Al-Sm system

“…The range of temperature associated with the transitions observed on heating are also shown for comparison, where diffusivity is changing rapidly but remains many orders of magnitude below that expected for T/Tm ~ 0.8 and above. Notes on specific data: (a-d) based on oscillating viscometer measurements [38], (e-f) based on thermo-mechanical analyzer measurements [39], (g) each point shown is used here to represent a range of visocity measurements using a dynamic mechanical analyze under vibrational loading [40], (h) based on a reported semi-empirical viscosity-temperature relation reported for the range shown [41][42][43], (i) based on a reported semi-empirical viscosity-temperature relation obtained from solidification interface velocity measurements [44,45].…”