Fabrication and characterization of ultra-fine grained tungsten by resistance sintering under ultra-high pressure

The consolidation behavior of tungsten powders with different particle size (ranging from submicron size to several microns) have been investigated by using a novel method combining resistance sintering with ultra-high pressures. The densification effects of the consolidation parameters, including pressure, input power and sintering time, have been investigated. High density is achieved for consolidation of micron sized tungsten powder and the microstructure retained its fine-grain size. The sintered samples achieve higher hardness and bending strength when the finer powder is used. The sintering mechanism of this method was quite different from other sintering techniques.