Multilayer graphene reinforced functionally graded tungsten carbide nano-composites. (15th November 2017)

• Record Type: Journal Article
• Authors: Sun, Jialin; Zhao, Jun; Chen, Mengjie; Zhou, Yonghui; Ni, Xiuying; Li, Zuoli; Gong, Feng
• Is Part Of: Materials & design. Volume 134(2017)
• Page Start: 171
• Page End: 180
• Publication Date: 2017-11-15
• Subjects: FGM -- MLG -- Microstructure -- Mechanical properties -- Tribological properties; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2017.08.041
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Mechanical and tribological properties of functionally graded multilayer graphene (MLG) reinforced WC-TiC-Al2 O3 ceramics prepared employing two-step sintering (TSS) are determined in this paper. Results showed that MLG can act as not only an exceptional reinforcement phase, but also a superior lubricant phase. A 0.1 wt% MLG/WC-TiC-Al2 O3 ceramics exhibits ~ 53.3% enhancement in fracture toughness, ~ 73.8% decrement in friction coefficient, ~ 82.65% improvement in wear resistance in comparison with monolithic ceramics. MLG bending, wrapping, interface debonding, MLG wall and network, MLG induced weak interface, grains bridging by MLG, MLG pullout, crack deflection, crack bridging and crack stopping are the major toughening mechanisms. The dramatic improvement in tribological performance is attributed to the self-lubrication of MLG and easily formed friction layer in the contact interface. Furthermore, the unrivalled thermal conductivity of MLG and its rather significant effect in inhibiting the grain growth are the important contribution to the improved tribological performance. Therefore, the functionally graded MLG/WC-TiC-Al2 O3 ceramics are conducive to be engineered as high-speed cutting tools. Graphical abstract: Highlights: MLG-reinforced graded WC-based nono-composites were prepared through TSS. 53.3% enhancement in toughness was obtained by adding 0.1 wt.% MLG. Significant tribological properties improvement were obtained by adding 0.1 wt.% MLG. Toughening mechanisms and anti-friction and wear resistance mechanisms were studied.