Qiu Hao, Li Xiaoqiang, Pan Cunliang, Fan Jiafeng
National Engineering Research Centre of Near-Net-Shape Forming Technology for Metallic Materials, South China University of Technology, Guangzhou 510640, China.
Materials (Basel). 2023 Aug 16;16(16):5645. doi: 10.3390/ma16165645.
Due to the excellent properties of Ti (C,N)-based ceramics, such as high hardness, excellent wear resistance, exceptional thermal deformation resistance, and sound chemical stability, they have been widely used in cutting tools or molds. Thus, revealing their tribological behavior against hard materials is of great significance. Some studies have reported the tribological behavior of Ti(C,N)-based cermets and hard cermets, but so far, the effects of MoC additions on the frictional properties of Ti(C,N)-based cermets are still unclear. In this study, Ti(C,N)-10WC-1CrC-5Co-10Ni-x MoC cermets (x = 4, 6, 8, 10 and 12 wt.%) were sintered using a vacuum hot-pressing furnace. Furthermore, the core-rim morphologies of the sintered samples were observed in SEM images. Then, the wear resistance of the cermets was studied against a SiN ball at a 50 N load using the fretting wear test. Finally, the wear mechanism was characterized using a combination of SEM, EDS and XPS. The experimental results indicated that the wear mechanisms of the cermets were mainly abrasive wear, adhesive wear, and the formation of an oxide film. As the content of MoC increased from 4 wt.% to 12 wt.%, the friction coefficient and wear volume had a variation law of first decreasing and then decreasing, and reached minimum values at 6 wt.% and 12 wt.%, and the lowest friction coefficient and wear rate were 0.49 and 0.9 × 10 mm/Nm, respectively. The 6 wt.% MoC greatly improved the hardness and fracture toughness of the cermet, while the 12 wt.% MoC promoted the formation of an oxide film and protected the friction surface. The cermet with 6 wt.% MoC is recommended because it has comprehensive advantages in terms of its mechanical properties, tribological properties, and cost.
由于Ti（C，N）基金属陶瓷具有诸如高硬度、优异的耐磨性、出色的抗热变形性和良好的化学稳定性等优异性能，它们已被广泛应用于切削刀具或模具中。因此，揭示它们与硬质材料之间的摩擦学行为具有重要意义。一些研究报道了Ti（C，N）基金属陶瓷和硬质金属陶瓷的摩擦学行为，但到目前为止，MoC添加量对Ti（C，N）基金属陶瓷摩擦性能的影响仍不明确。在本研究中，使用真空热压炉烧结了Ti（C，N）-10WC-1CrC-5Co-10Ni-x MoC金属陶瓷（x = 4、6、8、10和12 wt.%）。此外，在扫描电子显微镜（SEM）图像中观察了烧结样品的核壳形态。然后，使用微动磨损试验在50 N载荷下研究了金属陶瓷对SiN球的耐磨性。最后，结合扫描电子显微镜（SEM）、能谱仪（EDS）和X射线光电子能谱（XPS）对磨损机制进行了表征。实验结果表明，金属陶瓷的磨损机制主要是磨粒磨损、粘着磨损和氧化膜的形成。随着MoC含量从4 wt.%增加到12 wt.%，摩擦系数和磨损体积呈现出先减小后增大的变化规律，并分别在6 wt.%和12 wt.%时达到最小值，最低摩擦系数和磨损率分别为0.49和0.9×10⁻⁶mm²/Nm。6 wt.%的MoC极大地提高了金属陶瓷的硬度和断裂韧性，而12 wt.%的MoC促进了氧化膜的形成并保护了摩擦表面。推荐使用含有6 wt.% MoC的金属陶瓷，因为它在机械性能、摩擦学性能和成本方面具有综合优势。
