强流脉冲离子束辐照WC-Co硬质合金的组织与性能

Microstructure and properties of WC-Co cemented carbide irradiated by high-intensity pulsed ion beam

用扫描电镜(SEM)、表面轮廓仪、X射线衍射仪(XRD)、电子探针(EPMA)和显微硬度计等方法,研究了强流脉冲离子束辐照WC-Co硬质合金的组织与性能。结果表明,HIPIB辐照使硬质合金表面发生快速重熔和Co粘结相的优先烧蚀,导致六方α-WC相向立方β-WC_(1-x)相转变,形成丘状凸起重熔烧蚀形貌;硬质合金表面硬度随束流密度和辐照次数的增加先增加后减小,归因于辐照硬质合金表面重熔致密化、Co粘结相优先烧蚀、β-WC_(1-x)相转变以及表面微裂纹的产生。

Microstructure and properties of WC-Co cemented carbide irradiated by high-intensity pulsed ion beam（ HIPIB） were investigated by using scanning electron microscopy（ SEM）,profilometer,X-ray diffraction（ XRD）,electron probe microanalysis（ EPMA） and Vickers hardness tester. The results show that the HIPIB irradiation induces rapid remelting and selective ablation of the cobalt binder phase on the surface of the WC-Co cemented carbides,resulting in the phase transformation from hexagonal α-WC to cubic β-WC_（1-x）underwent in the irradiated surface layer,forming a remelting and ablation morphology with dome shape projection. The surface microhardness of HIPIB-irradiated WC-Co cemented carbide first increases and then decreases with the ion current density and irradiation times increasing,which should be attributable to the remelting densification,selective ablation of the cobalt binder phase,β-WC_（1-x）phase transformation and the formation of microcracks.