Hardness of hexagonal tungsten carbide crystals as a function of orientation

Orientation-dependent hardness and nanoindentation-induced deformation mechanisms of WC crystals

“…First, only the indents located well inside the WC grains were taken into account: those which corresponded to the Co phase or the close grain boundary area The applied loads and the measured hardness values are converted into SI units; additional details can be found in the original papers [5][6][7][8][9][10][11][12].…”

“…Two essential common characteristics can be revealed in these macro-and microindentation studies [5][6][7][8]11] and nanoindentation reports [10,12]. Namely, the measurements were confined to only two different extreme orientations, showing that the measured hardness values obtained on basal planes are significantly higher than those on the prismatic orientation.…”

“…It is important to emphasise that the aforementioned hardness investigations were focused on the effect of the basal and prismatic orientations alone. The excellent microindentation study of Roebuck et al [11] is the only relevant paper in the field of the analysis of the general orientation dependence between basal and prismatic orientations.…”

“…Moreover, several macro-and microindentation-based studies have been carried out by optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations [5,6,[13][14][15][16], and also with the electron backscatter diffraction (EBSD) technique [11], to investigate the anisotropic deformation mechanisms. To the best of our knowledge no experimental results or theoretical models have been reported so far on the hardness anisotropy depending on the grain orientation under nanoindentation.…”

“…in the case of composites with preferentially orientated grains. Table 1 shows a summary of the results of the most relevant studies, which have been aimed to characterise the effect of crystallographic orientation of WC single crystals and WC grains in WC-Co systems on their hardness [5][6][7][8][9][10][11][12].…”