Decelerated aging in metallic glasses by low temperature thermal cycling

Rejuvenation in Deep Thermal Cycling of a Generic Model Glass: A Study of Per-Particle Energy Distribution

“…The response, which develops inside the cubic simulation box, is regular, and it is difficult to see from this plot a significant effect of thermal cycling. Inline with our previous report [20], this first estimate on the lack of a strong effect in the cubic box is corroborated by a more detailed analysis below, where the variance is found to increase slightly while at the same time average energy per particle decreases.…”

“…However, to date, the literature on effects of deep thermal cycling is rather controversial. While rejuvenation was reported in findings from experiments on Cu 46 Zr 46 Al 7 Gd 1 and La 55 Ni 10 Al 35 metallic glasses [13,18], other experimental studies showed that, depending on the material and its composition, both rejuvenation and aging [19,20] can occur.…”

“…We have recently investigated the effects of thermal cycling on a simple model system, the Kob-Andersen binary LJ glass but could not observe any detectable sign of rejuvenation in none of the cubic simulation boxes containing sixteen thousands up to 1.2 million particles [20]. However, while calorimetry experiments are in line with this absence of detectable effects of deep thermal cycling [20], recent tracer diffusion experiments performed on Pd 40 Ni 40 P 20 bulk metallic glass samples seem to indicate enhanced diffusion upon thermal cycling [24].…”

“…Here, we revisit this issue with the same generic glass model as investigated in [20] but tune two important parameters. On the one hand, we increase the aging time prior to cycling (thus producing a more relaxed initial state) and at the same time enhance the cycling frequency.…”

Yielding transition in stable glasses periodically deformed at finite temperature

“…Common examples include high-pressure torsion, cold rolling, wire drawing, irradiation, elastostatic loading, as well as surface treatments like shot peening [6]. Here, we highlight a recent discovery that thermal cycling between the room and cryogenic temperatures can lead to rejuvenation of metallic glasses due to heterogeneous thermal expansion [7][8][9][10][11][12][13][14][15][16][17][18]. Remarkably, it was also recently demonstrated experimentally and by means of atomistic simulations that cooling across the glass transition temperature under applied stress rejuvenates amorphous alloys and increases their ductility [19,20].…”