OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 26 No. 1 2024 g h i j Fig. 2. The End the liquid phase before solid solution crystallization. It’s worth noting that some intermetallic compounds contain titanium, which is a result of using a titanium spoon during molten metal handling. The microstructure of specimens cast in a copper chill mold is illustrated in fi gure 2, while fi gure 3 shows the variation in grain size depending on the concentration of the element. It is worth noting that for comparison, fi gure 3 contains the results of the dependence of grain sizes on the concentration of chemical elements during casting into a steel mold, taken from [21]. The basic alloy, containing no erbium and hafnium, has a dendritic structure with an average grain size of 372 μm. It is worth noting that some grain sizes vary from 600 to 800 μm, while others stay within the range of 100–200 μm, as illustrated in fi gure 2, a. With the addition of 0.03 % Er and 0.05 % Hf to the basic alloy, the average grain size decreases to 181 μm. The number of grains with sizes of 600–800 μm decreases, while the number of grains with sizes of 100–200 μm increases, as shown in fi gure 2 b. With 0.03 % Er and 0.1 % Hf, the average grain size continues to decrease and reaches 175 μm. Most grains have sizes of 300–400 μm or 100 μm. At the same time, the fi rst 50 μm equiaxed grains appear, as seen in fi gure 2, c. With 0.03 % Er and 0.16 % Hf, the average grain size decreases to 86 μm, and almost all grains become equiaxed, as shown in fi gure 2, d. At 0.1 % Er and 0.05 % Hf, the average grain size reaches 113 μm, and two types of grains are observed: suffi ciently coarse 300–400 μm and fi ner 100–200 μm grains, maintaining overall dendritic structure (fi gure 2, e). In the alloy containing 0.1 % Er and 0.1 % Hf, the average grain size is 105 μm, and the overall pattern doesn’t diff er much from the previous case
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