Mechanical and thermal properties of hot pressed ZrB2 system with TiB2

• Study the effect of TiB2 loading on hardness and fracture toughness of ZrB2-TiB2 compared to monolithic ZrB2 ceramic
• In depth study of the scratch resistance and wear resistance of ZrB2-TiB2 and compared to monolithic ZrB2 ceramic
• Study of the thermal conductivity and diffusivity of ZrB2-TiB2 from around 100oC to 1000oC temperature
• Analysis of the Kapitza resistances of monolithic ZrB2 and ZrB2-TiB2

ZrB2-TiB2-based ceramics with varying amount of TiB2 (up to 30 wt%) were hot pressed at 2200 °C in Ar atmosphere, and the effect of the TiB2 addition on mechanical properties like hardness, fracture toughness, scratch resistance, wear resistance and thermal conductivity of the system was compared to monolithic ZrB2 ceramic. It was found from X-ray diffraction that TiB2 completely entered into the structure and formed solid solution with ZrB2. Addition of TiB2 in ZrB2 system improves the mechanical and wear resistance properties. ZrB2-TiB2 (30 wt%) ceramic, for example, showed highest hardness of 22.34 GPa, fracture toughness 3.01 MPa(m)1/2 and lowest coefficient of friction (0.398 at 10 N load). The addition of TiB2 in ZrB2 system showed lower thermal conductivity than monolithic ZrB2 by increasing grain boundary thermal resistance.