A Novel Approach by Spark Plasma Sintering to the Improvement of Mechanical Properties of Titanium Carbonitride-Reinforced Alumina Ceramics

Ti(C,N)-reinforced alumina-zirconia composites with different ratios of C to N in titanium carbonitride solid solutions, such as Ti(C-0.3,N-0.7) (C:N = 30:70) and Ti(C-0.5,N-0.5) (C:N = 50:50), were tested to improve their mechanical properties. Spark plasma sintering (SPS) with temperatures ranging from 1600 degrees C to 1675 degrees C and pressureless sintering (PS) with a higher temperature of 1720 degrees C were used to compare results. The following mechanical and physical properties were determined: Vickers hardness, Young's modulus, apparent density, wear resistance, and fracture toughness. A composite with the addition of Ti(C-0.5,N-0.5)n nanopowder exhibited the highest Vickers hardness of over 19.0 GPa, and its fracture toughness was at 5.0 Mpa center dot m(1/2). A composite with the Ti(C-0.3,N-0.7) phase was found to have lower values of Vickers hardness (by about 10%), friction coefficient, and specific wear rate of disc (Ws(d)) compared to the composite with the addition of Ti(C-0.5,N-0.5). The Vickers hardness values slightly decreased (from 5% to 10%) with increasing sintering temperature. The mechanical properties of the samples sintered using PS were lower than those of the samples that were spark plasma sintered. This research on alumina-zirconia composites with different ratios of C to N in titanium carbonitride solid solution Ti(C,N), sintered using an unconventional SPS method, reveals the effect of C/N ratios on improving mechanical properties of tested composites. X-ray analysis of the phase composition and an observation of the microstructure was carried out.

Automated summary

This research investigated the mechanical properties of Ti(C,N)-reinforced alumina-zirconia composites with different ratios of C to N using spark plasma sintering and pressureless sintering methods. The addition of Ti(C-0.5,N-0.5)n nanopowder resulted in the highest Vickers hardness and fracture toughness, while the composite with the Ti(C-0.3,N-0.7) phase showed lower hardness and specific wear rate. The mechanical properties slightly decreased with increasing sintering temperature, and samples sintered using pressureless sintering had lower properties compared to those sintered using spark plasma sintering.