Analysis of the kerf angle of the granite machined by abrasive waterjet (AWJ)

Abrasive waterjet (AWJ) cutting is one of the fastest growing machining processes which can machine almost any engineering material. However, the cutting capability of AWJ in terms of kerf quality is one of the major obstructions limiting its applications. Kerf angle, an important cutting performance measure, is a special geometrical feature inherent to AWJ machining and its high values are undesirable. It reflects the inclination of the kerf wall from the top surface to the bottom of the kerf. In this study, effects of process parameters and the material properties (i.e. textural properties) of the granites on the kerf angle are experimentally investigated. The design philosophy of Taguchi was followed to conduct experiments. Analysis of variance (ANOVA) was used to evaluate data obtained to determine the major significant process factors statistically affecting the kerf angle of the granites. The results revealed that the grains and their boundaries, the uniaxial compressive strength as well as the mineral compositions (especially feldspar and quartz) play the most important role for the kerf angles in the granites as material properties. Additionally, the most significant process factors influencing the kerf angle of the granites are statistically determined as the traverse speed, and the standoff distance.