Investigation of the Dendritic Structure Influence on the Electrical and Mechanical Properties Diversification of the Continuously Casted Copper Strand

Abstract

The properties of copper in its solid state are strongly affected by the crystallization conditions of the liquid material. ETP grade copper (Electrolytic Tough Pitch Copper) contains oxygen, which causes Cu2O 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. 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. The obtained results were confronted with scanning electron microscopy (SEM) images of the fractures formed during uniaxial tensile test. 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. 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. The differences in values vary in terms of the applied direction of the tensile force. A characteristic positioning of the Cu2O oxide particles inside the fracture depending on the crystallite alignment and the direction of the applied tensile force has been observed.

Pure Alloy Additive or Preliminary Alloy: A Comparative Study on Obtaining High-Strength Copper Magnesium Alloys Designed for Electrical Power Systems

“…However, above 3 wt.% of Mg, the difference is more than 1 MS/m. This is almost 2% of the pure copper electrical conductivity, which, when annealed, is equal to approximately 58 MS/m [3]. According to Nordheim's rule [44], when an alloy additive having atoms with a different diameter is introduced into the metallic matrix, the electrical conductivity must decrease.…”

“…Therefore, in line with the expected fall in carbon fuel consumption, the sales of electric and hybrid vehicles, not only in the United States, but also Europe and China, have increased in each of the past 10 years [1]. Bearing in mind that copper is an excellent electrical and thermal conductor [2,3], and is thus used in a large number of electrical applications, the development of copper manufacturing and processing industries is necessary for the modern power industry to improve [4]. Regarding the aforementioned vehicles, the production of an electric vehicle requires over two times more copper than a hybrid electric vehicle and over four times more copper than an internal combustion engine vehicle [5].…”

Shape Analysis of the Elastic Deformation Region throughout the Axi-Symmetric Wire Drawing Process of ETP Grade Copper

“…Some of the few empirical studies in recent years, conducted by Vega et al [ 29 ] and Tintelecan et al [ 30 ], proved that the drawing force in the process of copper wire drawing is influenced by the drawing angle, friction coefficient, and bearing length. The authors in [ 31 , 32 , 33 , 34 ] claim that there is a clear connection between the amount of oxygen and therefore copper oxides in the input material on the strength parameters of the materials, and thus the drawing forces, during the process. There is a noticeable modern trend towards lowering the occurring drawing forces, for instance by using various innovative lubricants such as graphite [ 35 ], PTFE [ 20 ], powdered soap [ 17 ], or MoS2 [ 3 ].…”

Research on Mechanical and Electrical Properties of Cu-Ag Alloys Designed for the Construction of High Magnetic Field Generators

“…These values are so significant that they may lead to the explosive destruction of not only the coil windings but also the electromagnet's body. The ideal material for the manufacture of the electromagnet coil winding should combine the high mechanical properties of steel with the electrical conductivity of a superconductor or copper [4][5][6][7][8]. Only then, due to the proper design of the coil and high intensity electric current flowing through the winding, may a magnetic field of a very high value be created.…”