Hutsaliuk O. Improvement of the process of cold reduction of short cylindrical billets by the methods of technological mechanics

The dissertation is aimed at solving the important scientific and technical problem of increasing the efficiency of the cold reduction process by providing recommendations on the limits of the use of the following technological parameters: the angle of inclination of the working cone of the matrix and the relative clamping of the workpiece, based on the use of methods of technological mechanics, taking into account the used plasticity resource. A map of an alloy of the W-Ni-Fe system (W- 89%, Ni - 7.5%, Fe - 3.5%) was formed, which contains: flow curve, standard mechanical characteristics, plasticity diagram and a graph of hardness – stress – strain. A simulation model of the reduction process is developed. The analysis of the stress-strain state, which allowed to establish the parameters of the reduction process (compression, angle of the matrix, coefficient of friction) and features of its mechanics in terms of uneven deformations, deformation paths, contact stresses. The expediency of using deformation criteria of deformability to determine the used material plasticity resource of the workpiece material in its characteristic areas, which are described by the ways of deformation of different curvature, is substantiated. An engineering dependence was obtained, which allows to calculate the calibration diameter of a matrix for single-cycle reduction, which ensures trouble-free formation. Theoretical and experimental studies of the influence of the angle of inclination of the tool and the magnitude of compression on the prediction of technological heredity have been performed.