In situ synthesized (ZrB 2 + ZrC) hybrid short fibers reinforced Zr matrix composites for nuclear applications

In the present work, novel zirconium matrix composites reinforced with ZrB 2 or (ZrB 2 + ZrC) hybrid short fibers were designed and prepared for the first time, through the reaction from Zr, B and B 4C with non-consumable vacuum arc melting. The result shows that the ZrB 2 particles grow in large short-fiber shape while the ZrC particles grow in thin short-fiber shape or near equiaxed shape. The morphological characters are related to their crystal structure and growth mechanism. Homogeneous distribution of both two in situ reinforcements can be found in the as-cast composites. As both the Zr matrix and the in situ reinforcements have good nuclear and mechanical properties, these Zr matrix composites are considered to be good candidates for applied as reactor core components. [Display omitted] ► Zr matrix composites reinforced with ZrB 2 and (ZrB 2 + ZrC) hybrid short fibers were designed and prepared for the first time. ► Homogeneous distribution of both two in situ reinforcements can be found in the as cast microstructure. ► Combination of good properties and chemical/thermal consistency makes the composites good candidate for nuclear and elevated temperature applications.