High frequency induction heated sintering of nanostructured Al2O3-ZrB2 composite produced by MASHS technique

Nanostructured Al2O3-ZrB2 composite was synthesized using an alternative route called Mechanically Activated Self-propagating High-temperature Synthesis (MASHS). It was demonstrated that Al2O3-ZrB2 composite with nanometric structure could be produced via a very fast combustion front in contrast with the SHS process. Ball milling for 5 h with ball to powder weight ratio of 5:1 was found to be the optimum condition for activation of the reactants. Using the high frequency induction heated sintering method, the composite was consolidated within 3 min. The relative density of the sintered sample was 99% of the theoretical density at an applied pressure of 20 MPa and temperature of 1800 °C. The average hardness and fracture toughness were 19.5 GPa and 4.1±0.3 MPa m1/2, respectively.