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

Abstract

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.