As part of the studies conducted in the field of broadly understood casting of non-ferrous metals, selected results on the impact of variable additions of copper and silicon in aluminium were presented. A series of melts was carried out with copper content kept constant at a level of 2% (1st stage) and 4% (2nd stage) and variable contents of silicon introduced into aluminium. The crystallization characteristics of the examined alloys and the percentage of structural constituents at ambient temperature were obtained by modelling the thermodynamic parameters of individual phases with the CALPHAD method. The microstructure of the obtained alloys was examined and microhardness was measured by the Vickers-Hanemann method. The alloy properties were assessed based on the results of mechanical tests, including ultimate tensile strength (UTS), hardness (BHN) and elongation (E). The machinability of the tested alloys was analyzed in a machinability test carried out by the Keep-Bauer method, which consisted in drilling with a constant feed force. The obtained results clearly indicate changes in the images of microstructure, such as the reduction in grain size, solution hardening and precipitation hardening. The changes in the microstructure are also reflected in the results of mechanical properties testing, causing an increase in strength and hardness, and plasticity variations in the range of 4 ÷ 16%, mainly due to the introduced additions of copper and silicon. The process of alloy strengthening is also visible in the results of machinability tests. The plotted curves showing the depth of the hole as a function of time and the images of chips produced during the test indicate an improvement in the wear resistance obtained for the tested group of aluminium alloys with the additions of copper and silicon.
An attempt to examine the earliest traces of non-ferrous metal metallurgy and casting in present-day Krakow has been made. The preparatory investigation has centred around a group of finds coming from a small section of the eastern part of the city, the area of Nowa Huta. The paper gives an overall view of objects ranging from the first copper artefacts from the territory of Poland in the 4th millennium BC through Lusatian bronzes and Celtic products to modern slag from Jan Thurzo’s copper smelter. The analysis, involving diverse copper or copper alloy artefacts, ornaments and tools – both imports and local products – has been aimed at preliminary identification of Krakow’s earliest metal artefacts in terms of their materials and methods of production, and at preparing the ground for further study. This multifaceted research is intended to result in a comparison of materials and techniques used in metallurgy and casting during the timespan of 5000 years.
PL
Podjęto próbę zbadania najstarszych śladów metalurgii i odlewnictwa metali nieżelaznych na terenie dzisiejszego Krakowa. Do pierwszych badań wybrano znaleziska z niewielkiego obszaru we wschodniej części Krakowa, obejmującego rejon Nowej Huty. Przedstawiono pierwsze zabytki miedziane z ziem polskich z IV tysiąclecia p.n.e., brązy kultury łużyckiej, wyroby celtyckie, aż po nowożytny żużel z huty miedzi Jana Thurzo. Do analizy wybrano zabytki miedziane i wykonane ze stopów miedzi, ozdoby i narzędzia, będące zarówno importami, jak i przedmiotami wykonanymi na miejscu. Celem pracy była wstępna identyfikacja materiałów, z których wykonano najstarsze zabytki metalowe odnalezione na terenie Krakowa, ustalenie technik wytwórczych, dzięki którym powstały, a także przygotowanie dalszych badań w tym zakresie. Rezultatem wielopłaszczyznowych badań będzie porównanie stosowanych surowców i materiałów oraz technik metalurgicz nych i odlewniczych na przestrzeni pięciu tysięcy lat.
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