Predicting the shape formation of parts with a flange and an axial protrusion in the process of combined aligned radial-direct extrusion

• Main Authors: Natalia Hrudkina, Leila Aliieva, Oleg Markov, Khrystyna Malii, Liudmyla Sukhovirska, Mykola Kuznetsov
• Format: Article
• Language: English
• Published: PC Technology Center 2020-10-01
• Series: Eastern-European Journal of Enterprise Technologies
• Subjects: simulation of combined extrusion processes; kinematic module; energy method; semi-finished product shape formation
• Online Access: http://journals.uran.ua/eejet/article/view/212018

Using the calculation schemes CS-1 (with the presence of a trapezoid module) and CS-1a (with rectangular kinematic modules) has been proposed for the process of the combined radial-direct extrusion of parts with a flange and an axial protrusion. The application of a trapezoidal kinematic module allows the description of the characteristic regions of metal flow, close to the actual course of the process based on the distorted coordinate grids. On the basis of the energy method, the values of the reduced deformation pressure have been obtained using the upper estimate of the power of deformation forces inside the trapezoidal kinematic module. The optimization involved the parameter Rk that determines the position of the surface of the interface of metal flow into an axial protrusion and a flange zone. We have performed a comparative analysis of the theoretical calculations of the magnitude of the reduced deformation pressure and the influence of geometric ratios and friction conditions on the qualitative and quantitative differences in the character of the change in the resulting curves. The overestimation of data on assessing the force mode based on the CS-1a scheme relative to the calculations based on the CS-1 scheme can be as high as 50 % and indicates the rationality of using the latter. This is due to the limitation in the use of the optimization (the absence of the optimization of the height of the deformation site) for the scheme containing elementary rectangular kinematic modules. The deviation from the experimentally obtained increments in an axial protrusion does not exceed 7‒10 %, which indicates the validity of the use of the CS-1 estimation scheme with a trapezoidal kinematic module. Thus, it can be argued that it is correct to determine the position of the boundary of the surface of the interface of metal flow into an axial protrusion and a flange zone and the resulting assessment of the formation of a semi-finished product