A critical review on spark plasma sintering of copper and its alloys

Abstract

Copper and its alloys have been in the service of humankind earlier than any other metal throughout history. In the present review, all aspects of the SPS of copper and its alloys are comprehensively investigated, and their potential effects on the microstructure and properties of alloys are thoroughly reviewed. In this regard, the densification phenomenon during SPS treatment is fully investigated. The effects of raw powder characteristics involving particle size, contamination content, and powder morphology on the sinterability of these materials are examined. Then, the influence of SPS operation parameters consisting of pressure, heating rate, dwelling time, pulsed electrical current, electrical pulses pattern, sintering temperature, and sintering tooling on densification of these materials is extensively discussed. Furthermore, the microstructure evolution and grain growth behaviors during SPS are explored. In addition, current challenges and future perspectives of this field are addressed.

Investigation of Electrical Transitions in the First Steps of Spark Plasma Sintering: Effects of Pre-Oxidation and Mechanical Loading within Copper Granular Media

“…This contributes to the model character of the powder, as the particles within the powder beds for the electrical measurements are well quasi-monodisperse. The raw powder has a density of 8.82 ± 0.01 g/cm 3 . This value is slightly lower than the theoretical density of copper calculated by XRD refinement (8.903 ± 0.002 g/cm 3 ) because of the presence of copper and tin oxides at the sur- For the reduced powder, at first sight, it may be considered that only the peaks characteristic of copper are indexed.…”

“…The raw powder has a density of 8.82 ± 0.01 g/cm 3 . This value is slightly lower than the theoretical density of copper calculated by XRD refinement (8.903 ± 0.002 g/cm 3 ) because of the presence of copper and tin oxides at the sur- For the reduced powder, at first sight, it may be considered that only the peaks characteristic of copper are indexed. However, by enlarging the low-angle part of the XRD diagram, the intensity of the characteristic Cu 2 O peak (2θ = 36.4 • ) is strongly attenuated after the reduction treatment at 400 • C for 2 h. Therefore, it seems that the applied heat treatment at 400 • C during 2 h in an Ar-H 2 atmosphere allows to reduce strongly the native oxide layer at the surface of copper particles.…”

“…Spark Plasma Sintering (SPS), which belongs to a set called the Field-Assisted Sintering Technique (FAST) [1,2], is used for the synthesis, consolidation and assembly of metals [3][4][5], ceramics [6,7] and composites materials [8][9][10]. This technique allows elaborating fully dense materials while maintaining the fine microstructure or even nanostructure of the starting powders [11][12][13][14][15].…”

“…Copper is well-known for its remarkable electrical properties with high ductility and known sinterability [34]. For these reasons, it is the desired candidate to investigate the sintering mechanisms of conductive powders [3]. The effect of electric current on the sintering of Cu spheres (3 mm diameter) arranged on copper plates (1 mm thick) was studied by Frei et al [35].…”

Electrical and Heat Distributions and Their Influence on the Mass Transfer during the Flash Spark Plasma Sintering of a Cu/Cr Nanocomposite: Experiments and Numerical Simulation

“…Owing to their unique mechanical, thermal, and electrical properties, copper-chromium nanocomposites are used in a variety of applications, particularly as vacuum interrupters [ 1 , 2 ]. These materials, which are mostly fabricated using powder metallurgy techniques, are extremely sensitive to manufacturing factors [ 3 , 4 ].…”