In Situ Synthesis of (Mo,Cr)Si2 Composites by Spark Plasma Sintering

This research investigated the impact of Cr content on the properties of (Mo,Cr)Si-2 composites. Composites with CrSi2 molar fractions ranging from 0% to 10% were fabricated using spark plasma sintering (SPS). The study undertook a systematic analysis of the surface morphology, phase composition, mechanical properties, and high-temperature oxidation resistance of the sintered samples across different compositions. Notably, the (Mo-95,Cr-5)Si-2 composite sintered at 1400 degrees C exhibited enhanced properties, including a Vickers hardness of 11.6 GPa, a fracture toughness of 4.6 MPa<middle dot>m(1/2), and a flexural strength of 397 MPa. Upon oxidation at 1500 degrees C, the (Mo,Cr)Si-2 composites formed a protective oxide layer comprised of SiO(2 )and Cr2O3. It was found that the generation and thickening of the protective oxide layer was promoted by the addition of moderate amounts of Cr to MoSi2.