Effect of plasma activated sintering (PAS) parameters on densification of copper powder

Copper (Cu) powder compacts were sintered by plasma activated sintering (PAS), and the effects of PAS parameters on the densification process of these compacts were investigated. A larger direct current caused a higher rate of temperature increase and therefore a higher densification rate of the Cu powder compact. Under a constant electric current, however, higher mechanical pressure resulted in a lower rate of temperature increase and a lower densification rate of the Cu powder compact. When the applied direct current was the same, the rate of temperature increase of the Cu powder compact after application of a 30-s pulse electric current remained higher than that without a pulse electric current. Application of the pulse electric current before application of the direct current was found to be effective in promoting the densification of Cu powder compacts. (C) 2000 Elsevier Science Ltd. All rights reserved.