Fabrication and Microstructure Evolution of Niobium-Niobium Silicide Composites by Spark Plasma Sintering

摘要

By using Nb and Si elemental powders as raw materials,dense Nb/Nb 5 Si 3 composites were successfully fabricated by a spark plasma sintering(SPS)technology.The microstructure of the fabricated composites was analyzed by OM,SEM,XRD and EPMA;the microstructure evolution of the composites was also investigated by a quenching test.The experimental results show that the prepared composites consist of Nb and Nb 5 Si 3 phases;Nb particle uniformly distributes in the in-situ synthesized Nb5 Si3 matrix.During the SPS process,an interfacial reaction occurs between Nb and Si particles to synthesize Nb 5 Si 3 until reactant silicon has been completely depleted.