Microstructural development of a C/C-ZrC-Cu composite prepared by reactive melt infiltration with Zr/Cu powder mixture

Zirconium carbide (ZrC) was introduced into porous carbon/carbon(C/C) preforms by reactive melt infiltration (RMI) using Zr/Cu powder mixture as the infiltrator. Characterization results revealed that ZrC particles were present in the infiltration matrix in two forms, some of which coalesced into a continuous layer around the pyrolytic carbon (PyC) while the others were dispersed within Cu phase which was distributed throughout the matrix. Nano-sized inclusions of Cu-ZrC were detected inside some ZrC particles. Furthermore, Cu-rich phase was observed at the interface between the continuous ZrC layer and PyC. The formation of Cu-ZrC mixture and Cu-rich phase was attributed to the trapping mechanism that some Zr-Cu-based liquid remained during the coalescence of ZrC particles or the formation of the continuous ZrC layer.