Taper of kerfs made in rocks by abrasive water jet (AWJ)

Abstract

The taper, inclination of cut side walls, is one of the characteristic phenomena of the abrasive water jet (AWJ) cutting. The taper represents a serious problem in shape cutting, especially in corners and curvatures. However, deviation of the side walls occurs even in the straight line parts of trajectories. Some differences from character typical for metal cutting have been noticed when studying the rock materials. This article is aimed at the experimental research of the cut walls taper on several rock materials with different genesis and composition. The topic of this contribution to the common knowledge is pointing out the most important differences compared to previous research made mainly on metals. The widths of slots made in plan-parallel plates of rock materials were measured both on the top and on the bottom. The difference between these widths has been used for evaluation of the taper—the angle of the cut walls inclination. The results were compared with the regression equation obtained from experimental results on metals and presented in past. The discrepancy between new findings and previously determined equation is discussed and the most probable explanations are submitted.