High-pressure preparation of bulk tungsten material with near-full densification and high fracture toughness

• The relative density of the prepared bulk tungsten material reach up to 99.5% ± 0.2%(number of measurement is three).
• The fracture toughness KIC of the prepared tungsten bulk material has been enhanced greatly, 50% higher than that from the traditional methods.
• The grain sizes of the sintered samples maintain in the initio range.

In this work, we present a novel method to sinter tungsten bulk material under high pressure without any additives. The sintering temperatures were greatly reduced in our experiments. The sintered samples can achieve near-full densification (relative density of 99.5%), and have fracture toughness of about 50% higher than that from the traditional methods, without sacrificing hardness. Moreover, the grain sizes of the sintered samples maintained in the initio range. The sintering kinetics, microstructure evolutions, and relationships of mechanical properties versus pressure–temperature conditions were also discussed.