Influence of an abrasive's characteristic on cutting capability in abrasive water jet cutting

摘要

The material removal models previously developed in abrasive water jet cutting disregarded the characteristics upon impact of the abrasive used. We conducted experiments aimed firstly at highlighting the transformation of the shape and size of two cutting abrasives of the garnet-red type (Barton and GMA) upon mixing, and secondly at showing the impact of the abrasive's size on cutting capability. We used video-microscopy to obtain the characteristics of shape of the abrasives, which are elongation and circularity; the distribution of size samples was defined by a laser particle size analyser. The abrasive fragmentation phenomenon during the process of mixture results in the abrasive particles becoming both smaller and sharper, which, depending on each case, either confers to them a greater erosive capability or allows them to preserve it. We introduced these characteristics into a new material removal model which becomes more precise. This new model extends to a broad range of pressures up to 380 MPa, with a broad range of abrasive sizes up to 470 μm. This makes it possible to determine the foreseeable height of a cut according, in particular, to the fraction χ of abrasive particles taking part in the mode of the erosion material removal by deformation. This fraction χ, itself a function of the transformation of the abrasive's size during the process of mixture, is defined by a specific model.