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The article presents the results of testing the flow curves of cast magnesium alloy MgAl9Zn1. Experimental tests were carried out on a deformation dilatometer in a compression test of cylindrical specimens heated to 380 °C, 400 oC, 420 °C at strain rates of 0,1 s-1, 1 s-1, 10 s-1. The experimental curves were described by functions used in programs for simulating metal forming processes based on the finite element method. The Generalized Reduced Gradient optimization method (GRDM) implemented in Microsoft Excel was used to determine the function coefficients. Based on the results obtained, the best functions characterizing the flow curves were selected for use in describing the material models used in numerical simulations of cast magnesium alloy MgAl9Zn1.

The article presents the results of testing the flow curves of cast magnesium alloy MgAl9Zn1. Experimental tests were carried out on a deformation dilatometer in a compression test of cylindrical specimens heated to 380 °C, 400 °C, 420 °C at strain rates of 0,1 s-1, 1 s-1, 10 s-1. The experimental curves were described by functions used in programs for simulating metal forming processes based on the finite element method. The Generalized Reduced Gradient optimization method (GRDM) implemented in Microsoft Excel was used to determine the function coefficients. Based on the results obtained, the best functions characterizing the flow curves were selected for use in describing the material models used in numerical simulations of cast magnesium alloy MgAl9Zn1. [ABSTRACT FROM AUTHOR]

The paper presents the study of the metallic-ceramic composite foams (the AlSi9 matrix, the SiC reinforcement) with application of the computer microtomograph. The morphology of these materials was also described in the paper, as well as generation of the three-dimensional models of the entire samples of foam. Additionally, quantitative image analysis was performed and the porosity of the test samples (with 3D analysis) and pore size distribution in the tested foams with different densities (with 2D analysis) was determined.

The paper presents mechanisms leading to the deformation of the spatial structure of composite foams and phases of foam destruction. Various types of deformation depending on the structure of foam are discussed. The relevant description makes use of recognized elementary models of a cuboidal open and closed cells. The production of foam by blowing a gas into a liquid composite (AlSi9–SiC) allows to control the quantity of energy absorbed during the destruction of foams subject to free one-axis compression.

The contribution summarises the results of application of thermodynamic calculation obtained from oxygen activities measurements in cast irons with various type of graphite microstructure. The results were used to find the relationship between natural logarithm of oxygen activities and reverse value of thermodynamic temperature 1/T.From obtained regression line the calculation of oxygen activities value for significant temperature of molten metal was achieved. Each material has its proper typical oxygen activities range for analysing and controlling graphite quality. Practical implication was successfully tested in a Czech foundry producing centrifugally poured cast iron rolls designed for hot strip mills with spheroidal graphite iron core.

Microstructural morphology of CoCrMo alloy by control of the cooling rate during the solidification was investigated. Samples were obtained using both an induction furnace for slow cooling rate and electric arc furnace for fast cooling rate. Microstructural characterizations were performed with metallographic techniques. It was found that the difference between the formation temperature of hard secondary phases of M23C6-type carbides determine the reduction of carbide size by increasing the cooling rate.

The paper presents mechanisms leading to the deformation of the spatial structure of composite foams and phases of foam destruction. Various types of deformation depending on the structure of foam are discussed. The relevant description makes use of recognized elementary models of a cuboidal open and closed cells. The production of foam by blowing a gas into a liquid composite (AlSi9-SiC) allows to control the quantity of energy absorbed during the destruction of foams subject to free one-axis compression. [ABSTRACT FROM AUTHOR]

The paper presents the study of the metallic-ceramic composite foams (the AlSi9 matrix, the SiC reinforcement) with application of the computer microtomograph. The morphology of these materials was also described in the paper, as well as generation of the three-dimensional models of the entire samples of foam. Additionally, quantitative image analysis was performed and the porosity of the test samples (with 3D analysis) and pore size distribution in the tested foams with different densities (with 2D analysis) was determined. [ABSTRACT FROM AUTHOR]

The contribution summarises the results of application of thermodynamic calculation obtained from oxygen activities measurements in cast irons with various type of graphite microstructure. The results were used to find the relationship between natural logarithm of oxygen activities and reverse value of thermodynamic temperature 1/T. From obtained regression line the calculation of oxygen activities value for significant temperature of molten metal was achieved. Each material has its proper typical oxygen activities range for analysing and controlling graphite quality. Practical implication was successfully tested in a Czech foundry producing centrifugally poured cast iron rolls designed for hot strip mills with spheroidal graphite iron core. [ABSTRACT FROM AUTHOR]

The aim of the carried out studies was to establish in what degree X-ray radiography is useful for finding defects in metal-matrix composite materials. These materials have various defects due to their specific composition. Especially when we take composites produced with casting methods into consideration. An effort to establish a degree of the influence of the phenomenon of electromagnetic diffusion on the boundary of matrix/ reinforcement phases was made in the results analysis of the studies.

Microstructural morphology of CoCrMo alloy by control of the cooling rate during the solidification was investigated. Samples were obtained using both an induction furnace for slow cooling rate and electric arc furnace for fast cooling rate. Microstructural characterizations were performed with metallographic techniques. It was found that the difference between the formation temperature of hard secondary phases of M23C6-type carbides determine the reduction of carbide size by increasing the cooling rate. [ABSTRACT FROM AUTHOR]

The aim of the carried out studies was to establish in what degree X-ray radiography is useful for finding defects in metal-matrix composite materials. These materials have various defects due to their specific composition. Especially when we take composites produced with casting methods into consideration. An effort to establish a degree of the influence of the phenomenon of electromagnetic diffusion on the boundary of matrix/reinforcement phases was made in the results analysis of the studies. [ABSTRACT FROM AUTHOR]