Abstract:In order to improve the properties of Co-8.8Al-9.8W-2Ta alloy, 0.4at.% Ce and B elements were added to study their effects on the microstructure and properties of the matrix alloy. The results showed that both Ce and B can inhabit the precipitation of the secondary phase, and spheroidize the secondary phase. Co3W phase is precipitated in the grain boundary region of 0.4Ce alloy, Ce mainly formed compounds Ce2Co17 and Al2Ce2Co15. And Co3W and Co7W6 phases are mainly formed in the grain boundary region of 0.4B alloy, and B element mainly formed compound CoW2B2. Both Ce element and B element can improve the microhardness of the alloy, and 0.4Ce alloy owned the highest microhardness.