| Popis: |
A lightweight titanium matrix composite material was fabricated by vacuum sintering using semi-powder metallurgy. The graphene nanoplatelets (GNPs) were used as a reinforcement for the titanium matrix composites. Fabricating the composite materials used three steps: dispersion, formation, and sintering. In particular, GNPs were dispersed by ionic liquid through a centrifugal testing machine instead of ball milling in the process. The better pressure for composite forming was 600 MPa. At the same time, the better sintering temperature and holding time were 1200 °C and 3 h. The influences of the GNP addition on the density, microstructure, and microhardness of the Ti/GNP composites were investigated. For the mechanical properties of the composites, we focused on the tensile strength with different GNP contents. The Ti 0.075 wt% and Ti 0.15 wt% GNP composites exhibited yield strengths of 850 and 948 MPa, which demonstrated 66% and 85% increase compared to those of extruded titanium materials with no GNP additive (512 MPa yield strength). The main strengthening mechanisms of Ti/GNP composites are grain refinement strengthening, thermal mismatch strengthening, and dispersion strengthening. |
