Abstract
The response of APC-2 (AS4/PEEK) processed with different thermal histories simulating different fabrication techniques was investigated. Three thermal histories were evaluated: (1) slow cooled (SC) from the melt state at 2°C/min; (2) rapidly quenched (Q) from the melt state by cold press transfer; and (3) quenched and annealed (Q/A) at 160°C. The SC APC-2 was found to have a fully developed semicrystalline matrix and the highest strength and modulus for flexural and shear tests, while the Q APC- 2 was found to have an essentially amorphous matrix and the greatest fracture toughness. In uniaxial creep tests of [±45°]2 S coupons both exposed and unexposed to JP-4, the unexposed Q specimens had the highest creep rates at room temperature and 100°C. The exposed SC specimens had the highest creep rates at 100°C because of the plasticization effect of the absorbed JP-4.