Microstructure and Properties of Spark Plasma Sintered SiAlON Composites Derived from Novel Precursors

This paper explores α/β-SiAlON composites, known for their exceptional mechanical and thermal properties, fabricated using spark plasma sintering (SPS). Novel reagents were initially introduced for the mechanochemical synthesis of precursors essential for producing α- and β-SiAlON phases via the carbothermal process. The prepared precursors were combined with active carbon in stoichiometric ratios and heated in a nitrogen (N₂) atmosphere for two hours. Characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM), confirmed the successful synthesis of SiAlON phases at ۱۵۰۰°C, revealing a range of morphologies.The results demonstrate that all composites sintered through the SPS process achieve complete densification at ۱۸۰۰°C. Mechanical properties, such as hardness and fracture toughness, are influenced by the ratios of α- and β-SiAlON phases. A composition of ۷۰% β-SiAlON and ۳۰% α-SiAlON exhibited optimal results, achieving a fracture toughness of ۴.۶۷ MPa•m¹/² and a hardness of ۱۷.۳۲ GPa, comparable to commercial samples produced using alternative raw materials.

کلیدواژه ها:

SiAlON Composites ، Novel Precursors ، Spark Plasma Sintering ، Carbothermal Reduction and Nitridation Process ، Mechanical properties