Effects of CeO₂ addition on microstructure and cavitation erosion resistance of laser-processed Ni-WC composites

Ni-WC metal matrix composite (MMC) with excellent cavitation erosion resistance (CER) was developed via laser-remelting to the sintered Ni-WC MMC. The robustness of the hierarchical WC lamellae contributed to the outstanding CER of the laser-remelted (LM) Ni-WC MMC, of which the relative CER was nearly twice greater than that of 316L stainless steel. Cerium dioxide (CeO₂) was also added, attempting to enhance the CER of the LM Ni-WC MMC further. However, despite a refined grain structure and improved microhardness were obtained in the LM Ni-WC-CeO₂, the CER was compromised due to that the modified morphology and distribution of the WC grains after the addition of CeO₂ were not very effective in enhancing the CER. The results indicated that the morphology and distribution of the WC particles exhibited a significant influence on the CER of materials, presenting a new aspect for studying cavitation erosion.