Effects of zirconium element on the microstructure and deuterium retention of W–Zr/Sc(2)O(3) composites

Dense W and W–Zr composites reinforced with Sc(2)O(3) particles were produced through powder metallurgy and subsequent spark plasma sintering (SPS) at 1700 °C and 58 MPa. Results showed that the W–1vol.%Zr/2vol.%Sc(2)O(3) composites exhibited optimal performance with the best relative density of up to 98.93% and high Vickers microhardness of approximately 583 Hv. The thermal conductivity of W–Zr/Sc(2)O(3) composites decreased initially and then increased as the Zr content increased. The moderate Zr alloying element could combine well with Sc(2)O(3) particles and W grains and form a solid solution. However, excess Zr element leads to agglomeration in the grain boundaries. W–1vol.%Zr/2vol.%Sc(2)O(3) composite had a good deuterium irradiation resistance very closing to pure tungsten compared with the other Zr element contents of composites. Under 500 K, D(2) retention and release of them were similar to those of commercial tungsten, even lower between 400 K to 450 K. Pre-irradiation with 5 keV-He(+) ions to a fluence of 1 × 10(21) He(+)/m(2) resulted in an increase in deuterium retention (deuterium was implanted after He(+) irradiation), thereby shifting the desorption peak to a high temperature from 550 K to 650 K for the W–1vol.%Zr/2vol.%Sc(2)O(3) composite.