Prediction of Spontaneous Plastic Deformation of Irradiated Metallic Glasses due to Thermal Spike-Induced Plasticity

Figures & data

Fig. 1. 475 keV Nb PKA passing through a ∼1/2 billion-atom model of a-Cu₅₀Nb₅₀. (a) Trajectory of PKA plotted in red,>1 keV KAs in black, and atoms displaced by 0.5–1 nm in blue. (b) Temperature fields due to inter-nuclear collisions. Red voxels have T_max>T_G=1, 500 K,[16] blue contour is for T_max=350 K. (c) TS-induced plastic deformation. Black voxels have ε^p>0.0125 at t=12 ps. The boxed TS is analyzed in detail in Figures 2 and 3.

Fig. 2. Stresses and strains inside and adjacent to the TS boxed in Figure 1(c). (a) Pressure versus time in the TS and in adjacent material. Von Mises stress (b) and tensile work-equivalent plastic strain (c) versus time, averaged over all voxels within 4 nm of the TS.

Fig. 3. (a) Close-up view of the TS boxed in Figure 1(c) with a cylindrical coordinate system defined along the TS major (z) axis and voxels with ε^p>0.0125 in black. (b) An initially ellipsoidal TS (dashed line) deforms into a more spherical shape (solid line) when internally pressurized, yielding the illustrated plastic strains in surrounding material. (c) Diagonal components of plastic strain computed at t=12 ps in cylindrical coordinates as a function of position along the major axis of the TS in (a). Shaded bands indicate uncertainties.

Fig. 4. (a) Voxel average plastic strain components in material adjacent to the seven largest TSs as a function of the TS energy. The arrow indicates the TS analyzed in Figures 2 and 3. (b) TS volume V_TS versus deposited knock-on energy E_TS. Linear fit: V_TS=(15.1±0.6 nm³/keV)E_TS−(8.9±11.2 nm³). Open symbols for TSs analyzed in (a).

Baumer RE, Demkowicz MJ. Glass transition by gelation in a phase separating binary alloy. Phys Rev Lett. 2013;110:145502. doi: 10.1103/PhysRevLett.110.145502

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