Fabrication of in Situ TiSi (Ti_5Si_3, TiSi)/TiC Local Reinforced Steel Matrix Composite via Combustion Synthesis

摘要

An in situ TiSi (Ti_5Si_3, 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 Ti_5Si_3 as well as TiC phases. SEM observation shows that the morphologies of the Ti_5Si_3 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 ～74μm DTA analyses show that, without addition of Cu, slight TiSi (TiSi_2 and Ti_5Si_3) 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 (Ti_5Si_3) compounds.