Micropillar compression of single crystal tungsten carbide, Part 1: Temperature and orientation dependence of deformation behaviour

Micropillar compression of single crystal tungsten carbide, part 2: Lattice rotation axis to identify deformation slip mechanisms

“…The basal pillar that was deformed at 600 °C (Figure 6b) shows lattice rotation about 〈112 ̅ 0〉 in most of the pillar, corresponding to 〈𝑐〉 prismatic slip. Slip trace analysis of this sample [1] showed that slip primarily occurred on prismatic planes, and basal slip was a minor slip system near the top of the pillar. In some regions near the top of the pillar, the misorientation axis is closer to 〈101 ̅ 0〉 (blue), possibly resulting from local secondary slip activity.…”

“…In in part 1 of this study [1], cylindrical micropillars with a 5 µm top diameter were fabricated using focused ion beam (FIB) in two WC single crystal samples, and compressed at five temperatures between room temperature and 600 °C. One sample was oriented with surface normal near [101 ̅ 0] ('prismatic sample'), and the other sample with surface normal near [0001] ('basal sample').…”

“…Slip trace analysis of the deformed pillars was performed to identify the slip planes activated at each deformation temperature. Details of the pillar fabrication, compression, and slip trace analysis, along with mechanical test data, are described in part 1 of this study [1]. Three deformed pillars and one undeformed reference pillar were selected for further analysis in the present study; the deformation conditions and measured slip plane traces and likely slip directions activated in these pillars are summarised in Table Cross-sections of the four pillars were extracted from the bulk sample and mounted on TEM half-grids using an in situ FIB lift-out technique.…”

“…A pillar deforming by geometrically constrained single slip would lead to lattice rotation about the Taylor axis given by (𝒏 × 𝒃). Active slip planes in these pillars were measured using slip trace analysis and are reported in Part 1 of this study [1].…”

“…Slip trace analysis has been applied to characterise deformation slip planes in single crystal tungsten carbide micropillars at both room and high temperature in Part 1 of this study [1]. This was combined with mechanical stress-strain data to provide insight into deformation and failure mechanisms of hardmetals in their typical operating conditions as cutting tools.…”