Spark Plasma Sintering of dense alumina ceramics from industrial waste scraps

ABSTRACT The implementation of environment-friendly manufacturing, which include the reuse and recycling of materials is nowadays crucial in order to meet the circular economy approach. The present study shows the possibility of recycling waste alumina scraps obtained after the green machining step during the manufacturing process of alumina ceramics as a broken ware, which contained small amounts (≤5 wt.% in total) of sintering additives in the form of organic binders and MgO. Dense alumina samples containing various amounts of waste alumina powder (0-100 wt.%) were produced by spark plasma sintering (SPS) at sintering temperature of 1450 °C, dwell time of 5 min at a 50 MPa of uniaxial pressure. The influence of waste alumina content on microstructure, hardness, and fracture toughness was investigated to determine the possibility of recycling broken ware.