Simultaneously enhancing the toughness and strength of cemented TiB2 nanocomposites through doping SiC whisker and graphene

Abstract

The current study applies towards investigate the sintering behavior, microstructure as well as mechanical properties of SiC whisker (SiCw) and multi-layer graphene (MLG) reinforced cemented TiB2 nano-composites fabricated through two-step sintering (TSS), highlighting the critical roles of SiCw and MLG as exceptional strengthening/toughening phases. The sinterability of TiB2–TiC–Ni was somewhat improved as a function of MLG or SiCw incorporation. The addition of SiCw resulted in the grain growth of matrix grains, whereas MLG addition significantly impeded the grain growth of TiB2. TSS is effective in suppressing the grain growth coupled with improving the densification in comparison with conventional sintering (CS). The major toughening mechanisms for SiCw/TiB2–TiC–Ni are SiCw bridging, crack deflection and branching. The major toughening mechanisms for MLG/TiB2–TiC–Ni are MLG bridging/pullout as well as crack deflection/branching/arresting. MLG is a superior reinforcement in comparison with SiCw.

Keywords

• Cemented TiB2
• SiC whisker
• Multilayer graphene
• Two-step sintering
• Mechanical properties