Deuterium absorption properties of Zr-xCu alloys prepared by SPS

Zirconium is a kind of deuterium absorption materials and can be used as a candidate deuterium carrier in the nuclear fusion industry. However, it usually cracks after deuterium absorption and fails in its application. For the prevention of cracks, copper particles with good ductility were added into the zirconium by spark plasma sintering (SPS) synthesis method. The results showed that the addition of the Cu element affected the cracking behavior of Zr-xCu alloys significantly. With the addition of the 5%Cu no cracking was observed, and an addition of the 10%Cu lead to an observation of a few large cracks within the second phase, compared in size to the small cracks that appeared in Zr. Moreover, the addition of the Cu element decreased the deuterium absorption capacity of the Zr-xCu alloys and changed the deuterium absorption mechanism from three-dimension diffusion in the Zr alloy to chemical reaction in the Zr-10%Cu alloy. The pressure-composition-temperature (PCT) curves showed that all the Zr alloys had two plateau pressures at 900 °C, and the addition of Cu had an effect on the plateau pressure. After 10 cycles of deuterium absorption-desorption, Zr-5%Cu sample kept a integrity morphology with no cracking at low magnification, on the contrary Zr-10%Cu sample broken into pieces, though both of them kept a higher relative deuterium absorption capacity than that of Zr.