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.

The article presents a new methodology for modelling the influence of parameters and conditions of surface grinding process on the value of roughness and grinding forces. Grinding processes are characterised by numerous factors influencing results of the process with a complex mechanism of the cumulative effects of their interactions. Therefore, authors for the development of the model used an artificial neural network. The input parameters of the model, apart from the processing parameters, were the properties of the workpiece and features of the grinding wheel. In the selection process of the neural model structure, an evaluation criterion was proposed which included the character of the influence of processing parameters on the resultant values of the grinding process for the given pair workpiece–tool. A high ability to data generalisation by the developed neural model was demonstrated.

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.

This paper presents an effectiveness analysis of the grinding process with the use of a new multi-layer abrasive tool. The designed abrasive tool consists of external layers with a conventional structure, whose task is to decrease the grinding wheel load and ensure high grinding volumetric efficiency. The inner layer of the grinding wheel contains a 30% addition of abrasive aggregates. The task of the inner layer is to provide lower roughness of the machined surface. The aim of the research presented in this paper was to evaluate the topography of the designed abrasive tool and to analyze the middle layer properties influencing the machined surface roughness. The differentiation of the active surface features of the abrasive tool was determined for the conventional layer and the layer with the addition of abrasive aggregates. The machining potential of the layers was also determined using the Shos parameter. The surface topography of Ti-6Al-4V alloys ground with the use of a multi-layer wheel and a conventional grinding wheel was analyzed. With the application of the bootstrap hypothesis, the set of roughness parameters differentiating the topography of ground surfaces was determined.

The shape of the cutting blades of the abrasive grains has an influence on the material separation process in the machining zone. The paper analyzes the influence of the geometrical parameters of the abrasive grains (rake angle γ, apex angle ε, opening angle α), as well as width b_z and length b_b of the cutting zone on the material removal efficiency. The material removal efficiency was determined taking into account the volume of the removed material V_G and the volume of lateral piles-up V_R. The analyses were carried out on the basis of the results of experimental and simulations using the finite element method. The relationship between the selected geometric parameters characterizing the cutting zone and the coefficient characterizing the efficiency of the material removal process was determined. A strong influence of the opening angle α as well as the width b_z and length b_b of the cutting zone on the material removal process by abrasive grain was demonstrated. It was observed that the wide cutting edge, and thus the large opening angle α of the grain, reduced the size of the pile-ups and more effectively removed the chip material.

Analysis of the shape and location of abrasive grain tips as well as their changes during the grinding process, is the basis for forecasting the machining process results. This paper presents a methodology of using the watershed segmentation in identifying abrasive grains on the abrasive tool active surface. Some abrasive grain tips were selected to minimize the errors of detecting many tips on a single abrasive grain. The abrasive grains, singled out as a result of the watershed segmentation, were then analyzed to determine their geometric parameters. Moreover, the statistical parameters describing their locations on the abrasive tool active surface and the parameters characterizing intergranular spaces were determined.