DENSIFICATION BEHAVIOUR OF W-Cu COMPOSITE COMPACTS PRODUCED BY LIQUID PHASE SINTERING AND CONTACT INFILTRATION PROCESSES

Abstract

Sintered compacts of W-Cu composites containing 20 – 50wt%Cu have been produced using liquid phase sintering (LPS) and contact infiltration processes.  The compaction pressures used to produce the starting green compacts ranged from 100MPa to 300MPa, and the sintering and infiltration temperatures ranged from 11500C to 12500C. The selected sintering time was one hour.  The relative densities of all green compacts and sintered/infiltrated specimens were determined.  For the specimens produced by the LPS process, the relative density values ranged from 90% to 93%, while for the infiltrated specimens, the relative densities ranged from 96.4% to 97.8%.  Cobalt coating of tungsten particles prior to sintering was found to be beneficial to densification, with the optimal amount of cobalt coating in the range of 0.45 to 0.50 wt% cobalt.  Higher sintering temperatures in the range of 12000C to 13000C also resulted in increased densification.  The results generally show that the infiltration process results in more efficient filling of pores and better densification than the LPS process.