Abstract
The dependency of creep strength for a thermoplastics Polyimide and its CFRP on time and temperature was researched. Especially, the effect of crystallization on creep phenomena was studied. And the strengthening method for creep fracture of Polyimide was discussed. For these purpose, the effects of mixing of fiber reinforcement and changing polymerization of resin on creep fracture strength were studied. Used material was a carbon fiber reinforced thermoplastics-polyimide and its fiber volume fraction was 15%. Two kinds of crystallinity were prepared, which were 0% and 31%. From the result of bending test, it was found that the strength and elastic modulus were straightly increased according to crystallization. On the other hand, fracture strain decreased due to this treatment. Using these materials, applied stress levels and test temperature dependence of the creep fracture strength were researched. The temperature conditions were from 220℃ to 280℃ which was a slightly over the glassy temperature of this resin.
