The aluminium alloy with chemical conception AlMgSi prepared by PM (powder metallurgy) technology was used. The experiments such as a ring and compression test, ECAR (equal channel angular rolling) for determination of friction coefficient, stress-strain curves and material workability based on analytical methods (Freudenthal, Cockcroft-Latham and normalized Cockcroft-Latham criteria) were performed. Numerical simulations of sample processed by ECAR was carried out by a software Deform 3D with focus on the description of stress, strain fields and workability criteria (Cockcroft-Latham and normalized Cockcroft-Latham). The prediction of fracture formations in a real ECAR sample during processing conditions was also done.Keywords: compression test, powder metallurgy, fracture criteria, ECAR, Deform 3DStop aluminium o składzie chemicznym AlMgSi przygotowano metodą proszkową. Wykonano badania takie jak próba ściskania swobodnego pierścieni i walcowatych, ECAR (wyciskanie w kanale kątowym z walcowaniem) w celu wyznaczenia współczynnika tarcia, krzywych naprężenie-odkształcenie oraz podatności materiału na odkształcenie z użyciem metod analitycznych (kryterium Freudenthal, Cockcroft-Latham i znormalizowane Cockcroft-Latham). Symulacje numeryczne dla próbki poddawanej procesowi ECAR przeprowadzono przy pomocy oprogramowania Deform 3D z naciskiem na opis pól sił i naprężeń oraz kryteriów obrabialności (Cockcroft-Latham i znormalizowane Cockcroft-Latham). Przeprowadzono również symulację możliwości tworzenia się pęknięć w rzeczywistej próbce poddanej procesowi ECAR.

To prevent any failure or fracture in materials during a forming process, the study of material workability is a crucial task. In this paper, the workability of two different aluminium alloys was described through Cockcroft -Latham ductile fracture criteria and forming limit diagrams. Moreover, the experiments have been carried out using compression tests and finite element methods and there was able to compare and verify the physical and numerical approaches. According to the results, there was found out that physical and numerical models are advantageous tools to describe the material workability during forming processes and the optimal data are obtained when both approaches are working together.

The determination of ductile fracture criteria as well as friction coefficient, stress-strain curves, constants for Hollomon's equation and a material workability based on analytical methods as a forming limit diagram, a normalized Cockcroft-Latham criteria (nCL)) ring and compression tests for two materials based on aluminum and copper alloys were carried out. A calculation of nCL criteria on the basis of a compression test and numerical simulations was made. The critical values nCL criteria resulting from compression test were determined. Prediction of nCL criteria by numerical simulations were confirmed by laboratory compression tests. The values obtained from numerical simulations and compression tests for both materials show a good coincidence in results.

This article deals about structural, mechanical and fatigue properties of an aluminium alloy EN AW 6061 (AlMg1SiCu) reinforced with SiC particles, in the initial state and in the state after intensive plastic deformation acquired by the process ECAP (Equal Channel Angular Pressing). In both states microstructures were evaluated with metallographic procedures, mechanical properties (yield strength, ultimate tensile strength, elongation) and fatigue curve at cyclic load in torsion. The main goal of this article was to study the influence of the intensive plastic deformation on an aluminium alloy reinforced with SiC particles prepared by powder metallurgy technique.