A novel rapid fabrication method and in-situ densification mechanism for ceramic matrix composite

Abstract

The extensive application of ceramic matrix composites has always been limited due to the long-period and expensive process. Hence, this research introduces a rapid manufacturing method named as ViS_fP-TiCOP (High Viscosity Solvent-free Precursor Combined Elemental Titanium Controlled Pyrolysis). The solvent-free precursor possesses high viscosity (30 °C, 10⁶ mPa S) and wide molecular weight distribution (M_z/M_w = 3.3), accomplishing stable loading of inorganic fillers. Simultaneously, the elementary titanium and ZrB₂, as the active and inert filler, are dopped into the precursor to control the pyrolysis. The ViS_fP-TiCOP technique offers a rapid method to manufacture CMCs under pressureless and low pyrolysis temperature conditions (1200 °C). Comparing to the addition of ZrB₂, the precursor with titanium provides an exceptional ceramic yield of 87 wt%, leading a notable enhancement in the rate of densification. This high densification efficiency is attributed to an in-situ titanium gas-phase reaction, besides with the high degree of cross-linking and low volatile of precursor. After undergoing three cycles of impregnation-pyrolysis, the porosity of C/SiBCN–Ti was discovered to be below 10 vol%, whereas that of C/SiBCN-25 wt%ZrB₂ still remained as high as 20.91 vol%. The ViS_fP-TiCOP technology can provide guidance for low-cost and rapid preparation of CMCs.