Figure 3.4 summarizes different methods for measuring the topography of grinding wheels. In the case of the carbon paper method, white paper and carbon paper are put between the grinding wheel and a slightly conical, polished plastic ring. The grinding wheel topography is reproduced on the white paper by rolling the grinding wheel on the plastic ring. Due to the conical shape of the ring, the measurement of the cutting edge distribution is expected to be dependent on the cutting area depth [Nakayama 1973].
3.3.4 Roughness Measures
Various surface parameters, RZ, RK, RVK, and RPK, are available as measures of topography and, in particular, the maximum profile height, Rp, is useful due to its integrating character for the specification of the grinding wheel topography [Schleich 1982, Werner and Kentner 1987, Warnecke and Spiegel 1990, Uhlmann 1994, Bohlheim 1995]. A further value derived from static methods is the static cutting edge number per length or surface unit N’S or NS [Daude 1966, Lortz 1975, Kaiser 1977, Shaw and Komanduri 1977, Verkerk 1977, Rohde 1985, Treffert 1995]. The cutting edges are determined on the basis of the envelope curve of the effective area of the grinding wheels, which is defined by the external cutting edges. With increasing depth, the cutting edges penetrate equidistant intersection surfaces or lines. Similar to a material ratio curve, a frequency curve of the static cutting edge numbers is formed depending on the cutting edge depth.
3.3.5 Qualitative Assessment
SEM, optical, and stereo-microscopic images are used for the qualitative evaluation of wear processes [Schleich 1982, Stuckenholz 1988, Dennis and Schmieden 1989, Warnecke and Spiegel 1990, Wobker 1992, Uhlmann 1994, Marinescu et al. 2004].