Chip formation, cutting forces, and tool wear in turning of Zr-based bulk metallic glass

Shear punch tests for a bulk metallic glass

“…Lacking temperature measurements, the thermal softening and strain rate effects proposed cannot be directly verified. A temperature rise above the glass transition for high-strain rate conditions and the lack of strain rate sensitivity for lower deformation rates, extracted from the parameters fit to the phenomenological equations, are consistent with other work on BAA-11 [29,31].…”

“…We attribute this drop to thermal softening resulting from strain rate induced heating. Bakkal et al [31] observed a similar drop in the cutting force during machining of BAA-11, which was accompanied by high temperatures and viscous flow features in the machining chips. Phenomenological equations will be used here to gain additional insight into the interplay of rate effects.…”

Influence of the Regime of Electropulsing-Assisted Machining on the Plastic Deformation of the Layer Being Cut

“…They also validated that decreasing the uncut chip thickness decreases the temperature in the primary shear zone which increases the shear strength of material and hence increases the SCE. Bakkal et al [21] demonstrated that high cutting speeds significantly reduce the SCE of materials with low thermal conductivity and high thermal softening effect.…”

Electron microscopy of bulk metallic glass machining chips

“…The lathe turning of a Zr-based BMG has been reported previously [1][2][3]. Above a threshold cutting speed, the low thermal conductivity BMG triggers the exothermic oxidation of the chip and produces extensive light emission.…”