The absolute method of penetrating gamma radiation has been used to measure temperature dependence of density for the Cu-Al alloys, which contain 0 to 100 at % of one of the components, in the tem perature range between room temperature and 1300-1400°C. Based on the experimental values of density, the parameters of the linear approximation of its temperature dependence have been calculated. These parameters have been used then to calculate values of density at certain values of temperature and to plot density isotherms. Density jumps at melting for the specimens have also been determined.

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Abstract. Al-Sn-Zn alloys are considered to be a good alternative for lead-containing solders; however, their physical properties at high temperatures are investigated insufficiently. In this work we have studied density (by gamma-absorption method), electrical resistivity (by contactless method in rotating magnetic field) and magnetic susceptibility (by Faraday's method) of some Al-Sn-Zn alloys containing up to 10 % of aluminum and up to 65% of zinc. The enlargement of zinc content resulted in the decrease in density and susceptibility values, except for one sample. The resistivity values practically didn't depend on zinc content in crystalline state, whereas it had maximum for one of the samples in liquid state, which might be attributed to the appearance of ternary high-melted intermetallic compound. The hysteresis, i.e. incoincidence of heating and cooling curves in electronic properties, which has been observed for tin-rich samples, might be due to irreversible transition from microheterogeneous state of the melt to true solution state. The work has been made in the frames of COST Action MP0602.

Abstract. Temperature dependences of the kinematic viscosity  and the density ρ of Al-Cu melts were investigated in the same regime taking into account that viscometric experiments with the melts enriched with cupper have not been repeated since 1960 th and densimetric measurements did not perform before at all. The first measurements were fulfilled using the method of dumping oscillation of a crucible filled in by a melt investigated. Its precision was as high as 1.5%. Density was measured using the gamma-absorption method with the accuracy of 0.2 to 0.3%. Crucibles of BeO were used in both the cases. In the course of the measurements a distinct branching of the heating and cooling curves were fixed below some temperature characteristic of each composition for most of the investigated samples. The branching temperature systematically changes with growth of cupper content. The authors believe that the effect is caused by the irreversible transition of the melts from microheterogeneous state inherited from the initial rough materials into a true solution state.