![]() The outer layers during crystallization process solidify first forming a thin, fine-grained zone of frozen grains. The microstructure of metallic materials formed during crystallization is called the primary structure and strongly influences the material macroscopic properties. The resulting dendrites grow until they begin to contact each other (crystallization fronts), which inhibits their further growth. Uniform growth of nuclei in all directions during the crystallization process and the preferential directions of heat abstraction (the direction is perpendicular to the surface of the casting mould) form the dendritic structure of the strand. The strand is obtained via a mobile casting mould and due to the symmetrical cooling of the strand surface a fast and uniform crystallization process of the liquid metal takes place. It is, in fact, a continuous casting process of copper strand directly subjected to the hot-rolling process. However, appropriate control of the material structure is much more difficult when the processes is conducted continuously such as strand casting process of copper intended for direct processing into wire rod designated for electrical purposes (Cu-ETP). The mechanical properties such as ultimate tensile strength (UTS) and YS of the material depend on its structure, which may be controlled throughout the technological processes. A characteristic positioning of the Cu 2O oxide particles inside the fracture depending on the crystallite alignment and the direction of the applied tensile force has been observed. The differences in values vary in terms of the applied direction of the tensile force. ![]() On the other hand, when the crystallites were arranged parallelly to the tensile direction the fractures were plastic and elongated necking was observed along with the higher YS and total elongation values. It has been observed that when the crystallites were arranged perpendicularly to the tensile direction the yield strength (YS) was lower and the fractures were brittle. The obtained results were confronted with scanning electron microscopy (SEM) images of the fractures formed during uniaxial tensile test. In the current paper the implied interactions of the dendritic structure of the copper strand in terms of homogeneity at the cross-section of its electrical, mechanical and plastic properties determined based on the samples taken parallelly and perpendicularly to the surface of the dendritic boundaries were analysed. ETP grade copper (Electrolytic Tough Pitch Copper) contains oxygen, which causes Cu 2O oxide to crystallize in the interdendritic spaces during solidification process which due to the shape of continuous casting mould and the feed of liquid copper during the crystallization process in strand casting might cause a high risk of macrosegregation of oxygen in the copper structure. The properties of copper in its solid state are strongly affected by the crystallization conditions of the liquid material.
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