Curing process and thermal stability of polyimide-matrix composite for aero-engines

Aiming at the need of aero-engines, investigation was made into the curing process and thermal stability of a polyimide-matrix structural composite. The curing kinetic equation of EC-380A resin was established. The curing degree of the resin was simulated as a function of the curing temperature and time. Further, combined with the resin rheology, the curing process of the EC-380A composite was established and verified. Large-scaled aero-engine typical structural components were fabricated. Thermal stability of the composite was estimated by mass loss, internal quality of the flaw-embedded laminate, and mechanical property after thermal ageing. By multi-temperature step curing at 330-380℃, the flaw-free composite could be manufactured under the circumstance of an integrated layup. The composite has excellent thermal stability with thermal resistance of 370-400℃. The mass loss rate is around 1.3% after ageing for 1000 h at 370℃ and 285℃.No new flaw or propagation of the embedded flaw occurs for the composite after thermal ageing at 400℃, indicating a high-temperature structural stability.