The influence of microstructural features on the electrical conductivity of solid phase sintered CuCr composites

Klinski-Wetzel, Katharina von; Kowanda, C.; Heilmaier, Martin; Mueller, F.E.H.

doi:10.1016/j.jallcom.2014.12.249

Cited by 30 publications

(6 citation statements)

References 24 publications

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“…Further microstructural parameters which might also contribute to a decreasing electrical conductivity like phase boundaries, porosity and impurities were discussed in Ref. [30]. Nevertheless, the present contribution shows that the altered electrical conductivity predominantly arises from the Cr-content supersaturated in Cu solid solution.…”

Section: Influence On Electrical Conductivitymentioning

confidence: 63%

Microstructure Formation and Resistivity Change in CuCr during Rapid Solidification

Hauf

Kauffmann

Kauffmann-Weiss

et al. 2017

Metals

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Abstract:The formation of the surface-near microstructure after a current interruption of CuCr contact materials in a vacuum interrupter is characterized by a fast heating and subsequently rapid solidification process. In the present article, we reveal and analyse the formation of two distinct microstructural regions that result from the heat, which is generated and dissipated during interruption. In the topmost region, local and global texture, as well as the resulting microstructure, indicate that both Cu and Cr were melted during rapid heating and solidification whereas in the region underneath, only Cu was melted and elongated Cu-grains solidified with the <001>-direction perpendicularly aligned to the surface. By analysing the lattice parameter of the Cu solid solution, a supersaturation of the solid solution with about 2.25 at % Cr was found independent if Cu was melted solely or together with the Cr. The according reduction of electrical conductivity in the topmost region subsequent to current interruption and the resulting heat distribution are discussed based on these experimental results.

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Section: Influence On Electrical Conductivitymentioning

confidence: 63%

Microstructure Formation and Resistivity Change in CuCr during Rapid Solidification

Hauf

Kauffmann

Kauffmann-Weiss

et al. 2017

Metals

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“…In fact, the orientation of whiskers also can affect the electrical conductivity greatly. Klinski-Wetzel had found that the Cr particles (aspect ratio>1) alignment leads to the electrical conductivity anisotropy of Cu-Cr composites [4]. It was further supported by Yang [21] with finding that the electrical conductivity parallel along the CNTs length direction was higher than that of vertical to CNTs length direction.…”

Section: Introductionmentioning

confidence: 89%

“…Copper matrix composites have high strength at the room, and the electrical and thermal conductivity close to pure copper, which are widely used as high voltage dynamic/static contact, electromagnetic gun orbit, electric resistance welding electrodes, etc. [1][2][3][4][5]. Ceramic particles and whiskers with excellent thermal stability and strength are used for reinforcing copper matrix composites [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Electrical conductivity anisotropy of copper matrix composites reinforced with SiC whiskers

Jiang

Guo

Zhang

et al. 2019

Nanotechnology Reviews

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Copper matrix composites reinforced with 1, 3, 5, 7 vol.% Cu-coated SiC whiskers of consistent orientation (SiCw/Cu) were prepared by powder metallurgy and hot extrusion. The microstructure of composites was investigated by scanning electron microscopy. The SiC whiskers were arranged along the direction of hot extrusion and distributed uniformly. The composites were fabricated into specimens with different whisker orientations, and their electrical conductivity was tested. The effects of SiC whiskers orientation and content on the electrical conductivity of composites were investigated through experiment. Results show that the SiC whiskers content was the major factor affecting the electrical conductivity of the composites. With increasing SiC whisker orientations angel, the electrical conductivity of composites is improved. The electrical conductivity model has been established by taking into account the SiC whiskers content, whisker orientation and microstructure parameters, and the results were in good agreement with experimental data. Graphical abstract: Copper matrix composites reinforced with SiC whiskers of consistent orientation were prepared. The orientation of SiC whiskers changes from 0∘ to 90∘, resulting in electrical conductivity anisotropy of composites.

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“…To investigate the factors influencing the electrical conductivity of CuCr alloys prepared by powder sintering method, Klinski-Wetzel et al [14] prepared CuCr25 and CuCr43 alloys by powder sintering and developed a model for the calculation of conductivity and validated the model by comparing it with measured values, as shown in Figure 6. It was found that the geometry of the Cr phase was the main factor affecting the electrical conductivity of CuCr alloys, as shown in Figure 7, while the effects of porosity and impurity elements seem to be minimal.…”

Section: Powder Sintering Methodmentioning

confidence: 99%

“…So far, the industrial production methods for CuCr alloys with diameters larger than 50 mm include the in ltration method [9][10][11][12], the powder sintering method [13][14][15][16], and the vacuum self-consumption arc melting method [17]. e CuCr alloys prepared by infiltration and powder sintering have defects, such as low density and uneven distribution of Cu and Cr phases, and great difficulties in preparing high-performance CuCr alloys with low gas content.…”

Section: Introductionmentioning

confidence: 99%

Progress in the Preparation of Large-Size High-Performance CuCr Alloys

Han

Zhang

et al. 2022

Advances in Materials Science and Engineering

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CuCr contact material, whose mass fraction of Cr is generally in the range of 25% to 50%, is one of the most desirable contact materials for medium- and high-voltage vacuum switches. The homogeneity and denseness of CuCr alloy are the keys to its application. The infiltration and powder sintering have defects, such as uneven distribution of Cr phase, and great difficulties in preparing high-performance CuCr alloys with low gas content; the equipment investment in the vacuum consumable arc melting method is large and the production cost is high, while mechanical alloying, vacuum induction melting, and laser-selective melting as new technologies are still in the laboratory stage. From the perspective of surface modification treatment and multicomponent alloying, refinement of Cr phase grains can improve the properties of CuCr alloy. The new process of aluminothermic reduction-electromagnetic coupling refining-water and gas composite rapid cooling takes oxides as raw material and obtains a fully miscible CuCr alloy melt by aluminothermic reduction theoretically at 2848K, followed by secondary refining under electromagnetic field coupling and water-gas composite cooling and casting, which can obtain alloy ingots of 50 mm in diameter and 10 mm in height. The density and hardness of CuCr alloy prepared by this process as vacuum contact material are better than the requirements of GB/T 26867-2011, so this process has the potential to become a new-generation preparation method for large-size homogeneous high-performance CuCr alloy.

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The influence of microstructural features on the electrical conductivity of solid phase sintered CuCr composites

Cited by 30 publications

References 24 publications

Microstructure Formation and Resistivity Change in CuCr during Rapid Solidification

Microstructure Formation and Resistivity Change in CuCr during Rapid Solidification

Electrical conductivity anisotropy of copper matrix composites reinforced with SiC whiskers

Progress in the Preparation of Large-Size High-Performance CuCr Alloys

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