Talum (Slovenia)

In modern practice standard materials do not satisfy the rigorous requirements for applications. Paper represents thermodynamic modeling of innovative aluminium alloys with better mechanical properties for high temperature applications. Using different combinations of alloying elements in specific temperature regions the information of which specific phase (solid solution, intermetallic compound) is formed. Alloys systems Al–X–Y (X = Si, Mn, Mg; Y = Zr, Mo) were investigated using thermodynamic equilibrium calculations (ThermoCalc), thermal analysis, and optical and scanning electron microscopy, in order to analyze the corresponding properties. Determination of chemical composition and types of phases, amount of phase and study of equilibrium and non-equilibrium processes, the characteristic solidification temperatures and mechanical properties for laboratory and industrial aluminium alloys was done.

The unsteady part of a cell pseudo-resistance signal called noise is closely related to electro-chemical and magneto-hydrodynamics processes, which is consequently reflected in its non-stationary and transient character, particularly in cases of different disturbances. Therefore wavelet transformation has been introduced in order to examine cell noise simultaneously within time-frequency space, thus enabling a deeper view of the process. A special data acquisition system has been installed on the AP18 Pechiney cell, with the capability of conducting continuous measurements of the cell's operating data, performing wavelet analysis and evaluating a result using the data obtained from the plantc ontrol system. In this paper the analysis and visualization of cell resistance noise, based on continuous wavelet transformation and wavelet packet transformation is proposed, in order to obtain complementary data for more efficient process control. The research results showed promising potential for using the wavelets for the visualization of dynamics and the detections of different disturbances during the aluminum reduction process.