热丝化学气相沉积金刚石时温度对YG6硬质合金的影响

Effect of Temperature on YG6 Cemented Carbide during Hot Filament Chemical Vapor Deposition Diamond

使用真空气氛滑轨管式炉将YG6刀片分别加热到750、850、950、1050℃,保温2 h,然后室温冷却。通过扫描电镜(SEM)、能谱仪(EDS)、X射线粉末衍射仪(XRD)、纳米压痕仪对硬质合金表面进行表征,并利用Image-J软件分析Co黏结相的变化。结果表明:加热后YG6表面产生脆性缺碳相(η相),部分fcc-Co转变为hcp-Co,导致硬质合金和金刚石薄膜的界面处易发生断裂。当温度达950℃后,表面Co含量大量上升,并且表面的硬度和弹性模量明显下降。

YG6 cutting tools were heated to 750 ℃, 850 ℃, 950 ℃,1050 ℃ by vacuum atmosphere slide tube furnace, respectively, followed by annealing for 2 h, and then cooling down to room temperature. The surface of cemented tungsten carbide was characterized by SEM, EDS, XRD and nano-indentation tester. The change of Co binder phase was analyzed by Image-J software. The results show that after heating, the brittle and poor-carbon phase emerges on the surface of YG6, and some fcc-Co converts to hcp-Co, which can lead to fracture at the interface of cemented tnngsten carbide and diamond film. When the temperature is 950 ℃, Co content on the surface increases significantly, while the surface hardness and elastic modulus obviously decrease.