Influence of sintering temperature on the electrical conductivity of Al2O3/Cu composites compacted by high velocity compaction

Abstract

Oxide dispersion strengthening(ODS) copper has the characteristics of both high strength and high conductivity. The porosity is an important factor influencing the electrical conductivity. 0.9Al2O3/Cu powder was compacted by a high velocity compaction(HVC) technique. The influence of impact velocity on the green density of Al2O3 dispersion strengthening copper was studied,and the green density of 8.46 g·cm-3 was got at the impact velocity of 9.4 m·s-1. The dependence of the electrical conductivity on sintering temperature was investigated. The results from sintering steps showed that the higher the sintering temperature was,the higher the electrical conductivity was at the same green density level. Fracture surface and SEM observations indicated that the samples were inadequately sintered at the sintering temperature of 950℃,with particle boundaries and some pores being visible obviously. When the sintering temperature rose up to 1080℃,the pores tended to spheroidize,the particle boundaries disappeared,and the dimples appeared on the fracture surface,showing a typical plastic fracture characteristic. The electrical conductivity of the sintered compacts was measured to be 71.3% IACS.

Keywords

• metallic matrix composites
• oxide dispersion strengthening
• copper
• alumina
• high velocity compaction
• sintering temperature
• electrical conductivity