The results of grinding are highly dependent on conditions of workpiece removal process. The material is removed by an unspecified number of abrasive grains of irregular shape and random distribution on the grinding wheel active surface. The interaction between the abrasive grain and the workpiece can be divided into three stages: (i) rubbing, (ii) ploughing and (iii) chip formation. Reciprocal contribution of each stage is dependent on the properties of the workpiece, the grinding parameters, the friction condition between the abrasive grain and the workpiece and the shape of the grains. In the article, the results of numerical and experimental process in the analysis of grinding of Ti-6Al-4V titanium alloy, using a conventional grinding wheel and a newly developed grinding wheel with aggregates of grains, were presented. The analysis of influence of the geometric parameters of the abrasive aggregates and the abrasive grains on the effectiveness of the workpiece removal process is presented. The effects of the geometrical parameters of grains and abrasive aggregates in direction of motion as well as in transversal direction on the size of ridges were determined. It has been observed that increase of the length of sideway material displacement results in the decrease of ridge formation. The results of a numerical analysis were confirmed by experimental research. The analysis of the impact of utilization of abrasive aggregates on the grinding forces, grinding-specific energy and surface roughness was performed. The impact of abrasive aggregates on the decrease of grinding forces and specific energy and the increase of quality of ground surface was observed.

Surface topography has a profound influence on the function of a surface

Modeling of material displacements in the microcutting zone is complex due to the number and interdependence of factors affecting the results of the process. An important problem in the modeling process is the selection of the constitutive model and its parameters, which will correctly describe the properties of the material under the conditions of triaxial compression, which is characteristic for the areas of the contact zone of the blade and the processed material in abrasive machining processes. The aim of the work was to develop computer models (with the use of the finite element method) of the microcutting process with a single abrasive grain, which were verified with the results of experimental tests. The paper presents the methodology of modeling the processes of microcutting with abrasive grains, whose geometrical models were created based on optical scanning methods. Observations of the microcutting process were carried out with the use of a high-speed camera and an optical profilometer. This enabled a detailed observation of the chip formation process, as well as the analysis of the surface topography of microcutting traces. The results presented in the paper indicate the convergence of the results of the numerical and experimental simulations with regard to the geometric parameters describing the scratches formed in the microcutting process and the compliance of the chip-forming process. Thus, the correctness of the selection of the constitutive model (Johnson Cook equation) and its parameters was demonstrated, as well as the correctness of the applied methodology for creating a geometric model that allowed for a reflection of the geometrical parameters of the abrasive grains that coincided with the real objects, thanks to which it was possible to reflect in detail the phenomena occurring in the vicinity of the abrasive grain tip.