Mechanical performance and microstructure of 3Y‐TZP/Al₂O₃/GNPs medical ceramic surgical scalpel material prepared through SPS–HF dual sintering method

Abstract

In this study, 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP)/Al 2 O 3 /graphene nanoplatelets (GNPs) medical ceramic materials for manufacturing surgical scalpels were sintered in vacuum in an SPS-625HF furnace. The mechanical performances and microstructures of the composites were investigated, and the influence mechanisms of the sintering temperature and amount of added GNPs were studied. During the sintering process at 1400 • C and 30 MPa for 5 min, the added GNPs enhanced the mechanical properties of the 3Y-TZP/Al 2 O 3 composites. The results showed that the composite with .1 wt.% GNPs had 6.4% (910 ± 11 MPa) higher flexural strength than 3Y-TZP/Al 2 O 3 . The composite with .4 wt.% GNPs had 38.7% (12.95 ± .22 MPa m 1/2 ) greater fracture toughness than 3Y-TZP/Al 2 O 3 . The main toughening mechanisms of 3Y-TZP/Al 2 O 3 /GNPs were crack bridging, crack deflection, crack branching, GNPs bridging, transgranular fracture structures, and phase transformation of t-ZrO 1.95 . The two-stage densification displacement curve appeared at the optimal sintering temperature of the materials, and the 3Y-TZP/Al 2 O 3 /GNPs composites with a two-stage densification displacement curve had excellent mechanical properties. The added GNPs can inhibit the grain growth during the sintering process, thereby refining the zirconia grains. With the increase in GNPs content, the grain size and flexural strength of the composites decreased gradually. However, higher content of GNPs was beneficial to improve the relative density and thermal diffusivity of 3Y-TZP/Al 2 O 3 /GNPs composite material.