Fabrication of in Situ TiSi (Ti₅Si₃, TiSi)/TiC Local Reinforced Steel Matrix Composite via Combustion Synthesis

Abstract

An in situ TiSi (Ti₅Si₃, TiSi)/TiC local reinforced steel matrix composite was successfully fabricated via combustion synthesis of Cu–Ti–Si system. XRD results show that the reinforced region of the composites is composed of Fe, Cu, TiSi and Ti₅Si₃ as well as TiC phases. SEM observation shows that the morphologies of the Ti₅Si₃ particles are coarse acicular/irregular particles and short fibrous/coarse elliptic shape in transition and reinforced region, respectively. TiC particles lie in transition region near the interface and their morphologies are polygon/quadrangle, with sizes of ~74 μm DTA analyses show that, without addition of Cu, slight TiSi (TiSi₂ and Ti₅Si₃) compounds form via solid diffusion process. After addition of Cu, Cu and Ti reaction occurs firstly, forming a serious of Cu–Ti compounds, at the same time, the reaction heat ignites the subsequent reaction of CuTi and Si and according forms TiSi (Ti₅Si₃) compounds.