The aim of this study was to analyze the crystallization of the Mg₇₂Zn₂₄Ca₄ metallic glass alloy. The crystallization process of metallic glass Mg₇₂Zn₂₄Ca₄ was investigated by means of the differential scanning calorimetry. The glass-forming ability and crystallization are both strongly dependent on the heating rate. The crystallization kinetics, during the isothermal annealing, were modelled by the Johnson–Mehl–Avrami equation. Avrami exponents were from 2.7 to 3.51, which indicates diffusion-controlled grain growth. Local exponents of the Johnson–Mehl–Avrami equation were also calculated. In addition, the Mg phase—being the isothermal crystallization product—was found, and the diagram of the time–temperature phase transformation was developed. This diagram enables the reading of the start and end times of the crystallization process, occurring in amorphous ribbons of the Mg₇₂Zn₂₄Ca₄ alloy on the isothermal annealing temperature. The research showed high stability of the amorphous structure of Mg₇₂Zn₂₄Ca₄ alloy at human body temperature.

This paper includes studies on the influence of grain refinement treatment with respect to the composition and structure of high zinc aluminium casting alloys on the changes of their tensile properties. The Al-20wt.%Zn alloy was inoculated with master alloys AlTi5B1 and AlTi3C0.15 to determine the impact of a variable titanium addition on the tensile properties of AlZn20 alloy, and determine on this basis an optimal addition of Ti that would ensure the improvement of elongation of alloys cast in the sand mould, at the same time maintaining high tensile strength. Within the studies, light microscopy (LM) and strength tests were applied. Experimental results showed that the inoculation of high zinc aluminium alloy AlZn20 with the master alloys AlTi5B1 and AlTi3C0.15 causes intensive structure refinement, while the intensity of reaction of both master alloys is comparable. The AlTi3C0.15 master alloy addition, selected for further studies, introducing about 100 ppm Ti, enhances the tensile properties of the alloy; the elongation increases about 20% and tensile strength increases about 10% against the initial values (uninoculated alloy). Further increase of the Ti addition up to 500–600 ppm leads to the “overinoculation” effect that is accompanied by the decrease of elongation. Therefore,the Ti addition should be reduced to the level of about 100 ppm which ensures obtaining a set of optimal properties.

The paper concerns double high-zinc aluminium alloys inoculated with master alloys containing titan and comprises research on the influence of inoculation on grain refinement. Most aluminium alloys before being cast have relatively low strength properties and therefore a series of treatments are applied in order to improve these properties. One of the treatments is the grain fragmentation process, called grain refinement treatment that allows to improve material properties of alloy, improve the feeding properties during the casting solidification, as well as to obtain more robust machinability of casting. Al alloy with 20wt% Zn (AlZn20) was tested, inoculated with the addition of traditional master alloy AlTi3C0.15 before casting to the sand mould. The results obtained during the studies show nucleating activity of the master alloy, proved by reduced overcooling and recalescence on cooling curves. Additionally, the role of titanium in this process is explained.

The presented work is aimed at determining thermal diffusivity, thermal conductivity and heat capacity coefficients of silica quartz bentonite foundry sand. The values of the above thermo-physical properties were determined for temperature range of about 30 - 450 °C using the Casting measuring method [1-. The results obtained during the examinations presented in the paper can be useful when formulating boundary conditions in numerical models of heat and mass transfer in the system: casting mould ambient. The Casting method allows preserving real conditions during the experiment, i.e. contact of the mass with liquid metal and solidifying casting, and the obtained results are in a good agreement with the mean values available in literature. From the obtained results it follows that examinations should be also focused on thermo-physical properties vs. mass density dependency.

The paper presents results of measuring heat diffusivity and thermal conductivity coefficients of used green foundry sand in temperature range ambient − 600 °C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were evaluated. It was confirmed that the obtained relationships are complex and that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured and solidified casting.