A comparative experiment for the analysis of microwave and thermal process induced strains of carbon fiber/bismaleimide composite materials

Carbon fiber reinforced bismaleimide composites provide many outstanding properties and are widely used in aerospace applications. However, cure-induced strains are present in virtually all composites that severely impact on the whole service lifecycle of composite components. This paper will demonstrate that the cure-induced strains can be drastically reduced in fiber/bismaleimide composites using the microwave curing process. Nearly 95% reduction of cure-induced strains has been achieved compared with the conventional thermal heating process. The microwave manufacturing cycle for composites was only 36% of the thermal processing cycle. When using the microwave process, the spring-in angle of an L-shaped part was reduced by about 1.2° compared by using thermal heating.