High-intensity pulsed ion beam (HIPIB) irradiation onto WC-Co cemented carbide was performed at a power density of ~ 10⁸ W/cm² up to 10 shots. The surface morphology and microstructures of the irradiated cemented carbides were investigated by using scanning electron microscope and X-ray diffractometer. It was shown that HIPIB irradiation led to a notable change in the morphology, presenting a roughening trend from waviness to top-rounded protrusions under multi-shot irradiation. The morphological modification was mainly related to the selective ablation of Co binder. Phase transformation from WC to WC_1-x was found after 1-shot HIPIB irradiation along with formation of ternary W-Co-C compounds and the amount of new phases was increased as proceeded with multi-shot irradiation. Surface remelting on the irradiated surface facilitates the chemical reactions of cemented carbide and Co binder, resulting in the phase transformation especially significant at the repetitive remelting. Surface hardness was enhanced by around 20% on the irradiated cemented carbides mainly due to formation of the new phase structure. Moreover, noticeable hardening to a deeper layer up to 100 mm was found for the irradiated cemented carbides. The topographical and phase modifications contributed to improved wear resistance of HIPIB-irradiated cemented carbides presenting a different worn feature.

X.P. Zhu*, Dalian University of Technology, China
F.G. Zhang, Dalian University of Technology, China
M.K. Lei, Dalian University of Technology, China

*presenting author