The purpose of the diploma work was to determine the suitability of moulding materials for casting aluminum alloys with lithium additions. We wanted to find out whether the moulds were made using the Croning and CO2 process and calcium silicate forms, in which coatings that have a graphite, graphite and zircon, and aluminate and graphite filler are suitable for the casting of said alloys. Considering that scientists have already tried to cast such alloys into steel and graphite forms, we also tested the suitability of these two. We were interested in the state of the molds after casting, the surface of the castings, and the porosity of castings.
The experimental work was initiated in such a way that a steel cell tool was first made, which was further used for the production of sandy forms made using the Croning and CO2 process. Forms of calcium silicate were cut out of silicate bricks, and pre-existing forms were used for graphite and steel form.
The results showed that casting in sandy forms and forms of calcium silicate, despite the use of coatings, does not produce the desired quality of castings. When using these forms, the samples were highly porous and a layer of lithium oxide was formed on the surface. Looking at cooling curves, a lot of reactions take place in the cooling of these alloys. Castings with good surface and less porous castings give casting to steel and graphite forms.
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