Effect of Surface Mechanical Attrition Treatment on Micro-mechanical Properties of ZrCuAlNi Bulk Metallic Glass

Abstract

In this work, surface mechanical attrition treatment (SMAT) was employed to rejuvenate ZrCuAlNi bulk metallic glass (BMG) plate. Differential scanning calorimetry (DSC), atomic force microscopy (AFM) and nanoindentation analyses were carried out to evaluate stored energy and micro-mechanical properties of treated BMGs. According to DSC results, 10 min SMAT process increased the stored energy of BMG plates up to 50%. AFM analysis showed that the structural rejuvenation occurred in the bulk of samples and just a slight rejuvenation gradient was detected from the front to the back side of BMG plates. Nanoindentation analysis indicated that the structural rejuvenation is consistent with anelastic strain induced under the SMAT process. It was also found that an optimum treatment time is needed for maximum rejuvenation in the BMGs. This event is due to the fact that the glassy structure is able to store a critical anelastic strain, which leads to a saturated condition in rejuvenation.

Role of compositional changes on thermal, magnetic, and mechanical properties of Fe-P-C-based amorphous alloys

“…With comparison of the d max and d f values, it is possible to find out the level of anelastic strain in the Fe-based alloys, which is indicator of loosely packed regions in the glassy structure. [45] The d f /d max ratio in the amorphous alloys reflects the level of anelasticity in the microstructure (see Fig. 4(c)).…”

Effect of spatial heterogeneity on level of rejuvenation in Ni80P20 metallic glass

“…This was identified as a key reason for the saturation of rejuvenation in the MGs. In another work, Shayakhmetov et al [17] showed that an optimized state exists for the rejuvenation under the mechanical attrition treatment, which may be due to the saturation of anelastic strain energy in the body of glassy material. Using the synchrotron x-ray diffraction, it was also found that in highly deformed regions under the highpressure torsion the local mean atomic volume is increased up to about 0.75%, thus achieving a saturated rejuvenated structure.…”