Microstructure and enhanced mechanical properties of ZrC/Zr composites added by in-situ Y2O3 reinforced particles

The in-situ hybrid particle-reinforcements are a novel strengthening mode for the advanced metal matrix composites . In this study, Zr matrix composites incorporating the fixed amount of ZrC particles with the different amounts of Y 2 O 3 particles were prepared by the in-situ reaction among Zr, graphite, Y, and ZrO 2 during the arc-melting. Results revealed that the graphite/Zr reaction produced the uniform in-situ ZrC particles in the Zr matrix, and the Y/ZrO 2 reaction formed the Y 2 O 3 particles. In-situ Y 2 O 3 addition refined the Zr matrix and led to the polygonal morphology of the ZrC particle. The coarser Y 2 O 3 grew in bulk, and some fine Y 2 O 3 dendrites were formed along Zr boundaries. The influence of different contents of Y 2 O 3 reinforcements on the hardness and compressive properties were analyzed. Compared with the single ZrC reinforcements, the hybrid Y 2 O 3 introduction resulted in a higher hardness and enhanced compressive strength . This hybrid structures were believed to be favorable to mechanical responses in the composites, and the relevant mechanisms for the hardening and strengthening effect of such hybrid forms were discussed.