PSI - Issue 41

A.M. Ignatova et al. / Procedia Structural Integrity 41 (2022) 527–534

530

4

Ignatova A.M., Vereschagin V.I., Naimark O.B./ Structural Integrity Procedia 00 (2019) 000–000

а b Fig. 2. Structure of cast samples of glass-ceramic spinel-piroxene materials: (а) first crystallization mode, (b) second crystallization mode.

Fig. 3. Schematic depiction of sample structures by two types of crystallization: (1) zone of direct contact with air; (2) a transition zone between air cooling and casting center; (3) zone without contact with the external environment; (4) a transition zone between the center of the casting and the zone of contact with the mold wall; (5) zone of direct contact with the mold. Table 2 specifies the average size of spinel formations, the maximum size of spinel formations, and the density of their distribution over the area. The average cooling rate value provided in the Table is obtained by calculation. This value is determined according to the distance of the zone from the edge in contact with air and according to the melt thermal conductivity data from the literature (Leontyeva, 1951). Analysis of data on the structural characteristics has shown that, depending on the local cooling rate and crystallization conditions, five zones can be distinguished, each having its typical parameters. There are five distinctive zones: zone of direct contact with air; transition zone between air cooling and casting center; zone without contact with the external environment; transition zone between the center of the casting and the zone of contact with the mold wall; zone of direct contact with the mold.