Ultrafast fabrication of W/Cu composites using flash sintering.

When the proportion of reinforcing phases is high and the wettability between the secondary phase and the metal is poor, preparing fully dense particle-reinforced metal matrix composites becomes challenging. This study employs the flash sintering method to prepare fully dense WCu20 composite materials within a few tens of seconds. It is found that during the "thermal runaway' process of flash sintering, the Cu phase undergoes rapid melting and solidification, and the core mechanism of material densification is that pressure causes Cu liquid to quickly fill the gaps between tungsten particles. Pressure not only promotes the contraction of the framework formed by tungsten particles but also facilitates the complete filling of gaps within the tungsten frameworks by the Cu liquid and promotes the rapid expulsion of bubbles from the Cu liquid, thereby achieving rapid densification of WCu20 composite materials. Moreover, an increase in the temperature enhances the fluidity of the Cu liquid, which aids in filling the gaps between tungsten particles and promotes the discharge of bubbles from the Cu liquid. Flash sintering is a common technique for the sintering and densification of metal powders, suitable for the rapid preparation of various metal matrix composites. • Fully dense WCu20 materials were prepared by flash sintering within 20 s. • Pressure has a core impact on the densification of flash sintering process. • The effect of the highest temperature on densification is studied. [ABSTRACT FROM AUTHOR]