In this diploma work we produced and analysed rapid solidified Al-Ni-La alloy. Our goal was successful production of ribbons and their further analysis with different research methods, so we could determine microstructure and important temperatures where microstructural changes occur.
We produced our alloy on melt spinner machine located at Department of Materials and Metallurgy – OMM. Product that we got were thin metal ribbons. After solidification those were analysed on machine for measuring electrical resistance. Based on the results of these measurements we could predict important temperatures where microstructural changes occur. Further analysis, that helped us to predict alloy properties even better, was analysis of microstructure. That was done on scanning electron microscope (SEM) where we also did chemical analysis of our samples. We also did thermal analysis with measurements of differential scanning calorimetry (DSC). After we finished with analysis on our sample, we heated alloy ribbons to temperatures that we predetermined with measurements of resistance so we could then see what microstructural changes occurred at this temperature interval.
Results of our analysis showed that we can obtain specific microstructure with rapid solidification on melt spinner, that can not be obtained by any other solidification method. Here we speak about cellular microstructure, that can be found in the upper part of ribbons under the surface. In the lower part of ribbon which was near contact with the surface area of a cylinder we obtained nano cellular microstructure. We aged our alloy into specific temperature ranges, in which some microstructural changes should happen, because on charts for electrical resistance we detected here some changes in its derivation. There were only minor changes in microstructure at those temperatures. We discovered that the cellular microstructure was decomposed and some globular particles were formed.
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