Effect of the rock grain size on the cutting performance of abrasive waterjet (AWJ)

Abrasive water jet (AWJ) is a technology commonly used in machining and/or processing of materials. In the technique, the cutting process is performed by high speed and pressured water penetrating to material. The cut depth, quality of cut and kerf angle which are indicators for AWJ cutting performance, are changed depending on the process parameters (e.g. traverse speed, abrasive flow rate, water pressure etc.) and the properties of material to be cut. In this study, effect of the rock grain size on the cutting performance of AWJ was experimentally investigated. In this respect, granite samples which are similar in mineralogical composition, but diverse in grain size were cut by AWJ. Following the cutting; the cut depth, the surface roughness and the kerf angle of each sample were measured. As a result of the study, it was seen that higher cut depths were obtained when the grain size of the rock decreased. In addition, it was determined that the cut surface of fine-grained rocks was rougher than the cut surface of coarse-grained rocks. On the other hand; bigger kerf angles were obtained in coarsegrained rocks, whereas small kerf angles were obtained in fine-grained rocks (granites).