Densification in liquid phase sintering under pressure in the system tungsten-copper

Conclusions

• 1. A study was made of the effects of applied pressure, liquid phase content, sintering temperature, the degree of wetting of the solid phase by the liquid, and solid phase particle size on densification in the system W-Cu.

• 2. Better wetting of the solid by the liquid phase helps the liquid penetrate into the interparticle contact zones, thereby increasing shrinkage and densification.

• 3. It has been established that shrinkage and densification in liquid phase sintering under a pressure exceeding the capillary pressure (for equiaxed solid phase particles and at any given volume fraction of solid phase) in systems exhibiting no significant intersolubility of components and containing a nonductile solid phase constituent are virtually or even completely independent of the solid phase particle size. When the solid phase possesses some ductility and is not fully wetted by the liquid phase, the degree of shrinkage slightly decreases with growth in particle size; this effect becomes more pronounced with rise in pressure.

• 4. The data obtained provide a basis enabling the optimum processing conditions, ensuring complete densification of sintered composites, to be determined.