Microstructure Analysis of the Alloy 625-nTiC Metal-Matrix-Composites Produced by Suction Casting

Alloy 625 is a Ni-based superalloy with the main alloying elements being Nb, Cr, and Mo. It is known for its excellent corrosion resistance, good weldability, both high heat and creep resistance, and good strength. The current work presents the microstructure of Alloy 625-nTiC metal matrix composites (MMC) fabricated through suction casting. The microstructure and chemical composition of strengthening phases were investigated by light microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that fabricated MMC composites are characterized by a dendritic microstructure with irregular distribution of the strengthening precipitates. Based on chemical composition analysis, the strong enrichment in Nb and Ti was revealed.