Fracture toughness of 3Al2O3☆2SiO2/Ag composites manufactured by high energy milling technology

The composites known as CERMETS are a combination between ceramics and metallic materials. The properties of these materials are different in comparison to conventional materials and their derivatives. The processing methodology of 3Al(2)O(3)*2SiO(2) reinforced with silver metallic particles (CERMET) was established and discussed in this research. The final chemical composition of the powder mixture obtained by high energy mechanical milling technology was 3Al(2)O(3)*2SiO(2) / 1 wt.% Ag in order to improve the fracture toughness aptitude as related to the ceramic base material. The milling was carried out for 2 hours at 200 rpm in dry. The powders were uniaxially pressed into cylindrical samples at a pressure of 200 MPa and then were subjected to a sintering treatment at 1500 degrees C and 1600 degrees C for 1 and 2 hours respectively using an electric furnace with nitrogen gas atmosphere. The resulted materials were microstructurally analyzed by using optical and scanning electron microscopy techniques. The density and the mechanical properties of hardness and fracture toughness were also evaluated, these last two were obtained by using the indentation method. The results showed the microstructural features and properties of density, hardness and fracture toughness have significant changes in CERMETS as that compared to unreinforced materials.