Investigation of the effect of combined thermomechanical processing on the brass microstructure evolution and the microhardness change

The article investigates the effect of combined thermomechanical processing, including pre-heat treatment and radial-shear rolling on the brass microstructure evolution and the microhardness change. The microstructure analysis of heat-treated samples according to various modes showed that the most optimal heat treatment before radialshear rolling for L63 brass is annealing at a temperature of 500 °C. As a result of combined thermomechanical processing, a gradient structure was obtained, so in the resulting rods with a diameter of 16 mm in the surface layer, a structure with an average grain size of 9 μm was obtained. In rods with a diameter of 12 mm, a fine–grained, equalgrained structure of 3 μm was obtained in the surface layer

Finite Element Modeling of ECAP-Linex Combined Process of Severe Plastic Deformation

The paper presents theoretical studies of a new deformation process combining the stages of equal-channel angular pressing (ECAP) and the "Linex"scheme. For correct finite element modeling of the process, a technique with sequential input for the calculation of conveyor links is presented. To analyze the efficiency of metal processing, the main parameters of the stress-strain state are considered: equivalent strain, equivalent stress, and average hydrostatic pressure, as well as the deformation force on the main elements of the combined process: pulley, matrix, and conveyor link. To analyze the resulting deformation forces, the stages of pressing in a matrix and compression by a chain conveyor were separately considered. Equations for determining the forces acting on the drive pulley, ECA matrix, and the chain element link were obtained. Comparison of values showed that the force values in the calculation and simulation have a high level of convergence. In all three considered details, the difference value did not exceed 10%. The variational modeling allowed to determine the optimal values of the main technological and geometric parameters of the process. © 2023 Evgeniy Panin et al

Damage criterion comparison at unidirectional and alternating torsion of samples

The paper presents the results of the analysis of computer simulation of unidirectional and alternating torsion of cylindrical samples in the software complex Deform 3D. The accumulated deformation degree and damage criterion were taken as compared parameters. Damage was calculated by two existing methods: Cockroft-Latham and Bogatov methods. The results of the analysis show that the proposed method for determining the damage criterion is more accurate when testing samples for alternating twisting than the most currently used method since it takes into account the number of loading stages and the plastic deformation amplitude. © Published under licence by IOP Publishing Ltd.BVD PECE spol. s r.o.;CSNMT;DynaWeld;EDAX;et al.;Linsei