Effects of Prior Aging at 191C on Creep Response of IM7/BMI 5250-4

The creep behavior of IM7/BMI 5250-4 with fiber orientations of [45] and [0/90] that were aged in air at 191C for up to 1000 hours was evaluated. The total weight loss during the aging process was also evaluated. Weight loss due to aging was 0.64% for the [0/90] fiber orientation and 0.72% for the [45] fiber orientation. Tensile tests to failure were conducted to establish tensile properties. The [0/90] specimens havea much higher stiffness and Ultimate Tensile Strength (UTS) values than the[45] specimens. The tensile tests of the aged specimens revealed that the Ultimate Tensile Strength of the composite decreased and the modulus increased with increasing prior aging time. Creep tests were conducted at 191C. The creep tests were of 100 hour duration and were followed by unloading to zero stress and 60 hours of recovery at zero stress.