The purpose of the presented paper was to examine the oxidation of Mg-Al alloys in the atmosphere of oxygen at various temperatures. The basic examination methods used were differential scanning calorimetry (DSC) and thermogravimetry (TG). The latter is based on recording the change of sample mass as a function of temperature. Oxidation process was analysed by the TG and DSC. The results show that the oxide layer can either protect the material against progressive oxidation or it can cause complete disintegration of material.
COBISS.SI-ID: 909151
This article describes the superplastic behavior of the Al-4.5Mg-0.46Mn-0.44Sc alloy. The elongations to failure were in accordance with the m-values. They increased with the temperature and were over 1000%, up to 1x10-3 s-1 at 480 C and up to 1x10-2 s-1 at 550 C. A maximum elongation of 1969% was achieved. The results show that the addition of about 0.4 wt.% of Sc to the standard Al-Mg-Mn alloy, fabricated by a conventional manufacturing route, including hot and cold rolling with subsequent recrystallization annealing, results in good superplastic ductility.
COBISS.SI-ID: 1004639
The stochastic nature of typical cold forging processes is assessed in this paper. Finite element computations have been applied to backward can extrusion, free upsetting, closed-die forging and forward rod extrusion in order to study the influence of scatter of the principal process input parameters on the dimensional accuracy of products and on the tool service life. The results show that stochastic interactions differ radically for the four typical cold forging processes and that press stiffness has a significant influence on the stochastic relationships.
COBISS.SI-ID: 1007711
To predict evolution of microstructure of aluminum alloys after deformation a numerical model based on the method of cellular automata (CA) has been developed and combined with the finite element model (FEM). The outcomes of this research demonstrate that numerical models can be successfully applied to simulate complex thermo-mechanical and metallurgical processes during hot extrusion.
COBISS.SI-ID: 1092959
Numerical modelling of the vertical mechanical press and a multistage forging system was performed in order to evaluate the tool loads, the displacements and the rotations of the entire WTP system. The press flexibility matrix in combination with finite element (FE) model of the press and multistage process enable predictions of the elastic displacements and rotations of the tool and the press ram as well as determination of the evolution of the resultant force in order to design a reliable multistage cold-forging process.
COBISS.SI-ID: 1116511