3.2.2 Macroscopic wear of G65 samples
In Fig. 12a, a cross section of the central wear zone of a worn tool steel after the G65 test made using optical microscopy is shown. Wear is not completely uniform and a distinct texture can be observed on all of the samples of the present study implying that the effect is independent of the wear material. Hutchings et al. refer to this phenomena as ‘furrows’ and suggest that the texturing is associated with a preferential channeling of multiple abrasive particles,[17]. Bourithis et al. also observed this phenomenon after wear testing of AISI D2 steel with the G65 test [18]. In Fig. 12b, a worn surface of the tool steel with a ‘furrow’ and the surrounding areas are shown. The ‘furrow’ exhibits multiple indentations which supports the proposed rolling motion of abrasive particles. The fact that the abrasive particles in the G65 test make contact with the wear samples by a combination of sliding and rolling could explain the selective removal of the matrix that were experienced in Section 3.2.1 in case of PM steel, tool steel and cast iron.