DEVELOPMENT AND CHARACTERIZATION OF SiC – Al 2 O 3– Al CERAMIC MATRIX NANOCOMPOSITE POWDER

In this study, SiC – Al 2 O 3– Al ceramic matrix nanocomposite powder was successfully synthesized employing mechanical alloying technique, through mechanochemical reaction among Silicon dioxide (SiO2), Carbon (C) and Aluminum (Al). For the commercial purposes, the materials ( SiO 2, C and Al powders) and also the method of synthesis (mechanical alloying) is considered to be cost effective for the production of SiC – Al 2 O 3– Al nanocomposite. Addition of alumina ( Al 2 O 3) and aluminum to silicon carbide (SiC) in a nancomposite form can improve the fracture toughness, strength and fatigue crack resistance of SiC and make it a leading material for many commercial applications specially by considering the cost-effective method of production. The structural evaluation of powder particles after different milling times was conducted by X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The results showed that during ball milling the SiO 2, C and Al reacted with a combustion mode producing SiC – Al 2 O 3– Al nanocomposite after 24 h ball milling and annealing at the temperature of 920°C. The crystallite sizes of phases remained in nanometric scale after annealing at 920°C for 1 h. Based on our investigation, it was revealed that ball milling and annealing process decreases the temperature of reaction between SiO 2 and C from 1500°C to 920°C.