Evaluation of Grain Shape Change by Lapping Pressure.
Shinsaku HAGIWARA, Hiroki Hongo, Toshiyuki OBIKAWA · Journal of the Japan Society for Precision Engineering · 1998
Lapping performance is essentially attributed to cutting abilities of grain, which depends on the grain shape. However, it was very difficult to evaluate the grain shape quantitatively, because the grain shape was changing complicatly during lapping. In this study, it was examined how the grain shape characteristics change with lapping pressure. In order to evaluate the grain shape, a new general attempt was made by the distribution of grain size and the aspect ratio from macroscopic point of view, by the fractal dimension from microscopic point of view. Here, the term “fractal dimension” can be defined as the complication of grain external line. As a result, macroscopic and microscopic characteristics of grain shape varied with lapping pressure. Increasing lapping pressure tended to be less the grain size and the aspect ratio, higher the fractul dimension. Namely, it follows that the grain will become round shape easily and at the same time have many micro edges on the grain surface in large size fracture.