Preparation, thermal cure and ceramization of liquid precursors of SiC-ZrC

Liquid PEPSI-PZO, as precursor of SiC-ZrC multi-component ceramic, was prepared by facile reactive blending method, using phenylethynylpolysilane (PEPSI) as silicon and carbon source and polyzirconoxanesal (PZO) as zirconium source. The processing capability of PEPSI-PZO met the demands of Precursor-infiltration-pyrolysis technique (PIP) in ceramic composites fabrication. The thermal cure was realized at 130-330 °C by ethynyl polymerization and condensations. The thermal cure of PEPSI-PZO precursor was promoted by catalyst Ni(acac)₂, and the curing initiation and curing peak temperatures decreased by 25 and 70 °C, respectively. Evidenced by ceramic yields and XRD results, the thermal pyrolysis was catalyzed by Ni(acac)₂, (ceramic yield was improved by 5-10%). XRD and SEM-EDS results showed that SiC-ZrC by 1600 °C pyrolysis was highly crystalline, due to the occurrence of carbothermal reduction reaction. The liquid precursor of SiC-ZrC is an ideal candidate of low cost precursors for high-temperature ceramics and ceramic matrix composites.