How does the autoclave cure process work for composites?

Autoclave curing uses heat and pressure in a pressurized vessel to consolidate and cure composite parts. Process: Layup - Prepreg plies placed on tool per engineering definition; Vacuum bagging - Bleeder, breather, release film, and vacuum bag over part; Load - Place bagged part in autoclave; Cure cycle - Ramp temperature, apply pressure, dwell at cure temperature, cool down. Typical cycle: Ramp 1-3C/min, dwell at 180C for 2+ hours, 100 psi (7 bar) pressure. Functions: Heat initiates and completes cross-linking reaction; Pressure consolidates plies, minimizes voids; and Vacuum removes volatiles and trapped air. Process parameters: Cure temperature and time (per resin system), Pressure (typically 85-100 psi for aerospace epoxies), and Vacuum level. Advantages: High quality parts with low void content (<1%), Well-controlled process. Limitations: High capital cost, Size limited by autoclave, and Energy intensive. Process monitoring includes thermocouples, dielectric sensors.