Acceleration of the curing process of a paste adhesive for aerospace applications considering cure dependent void formations

In this publication, the acceleration of the curing process of a paste adhesive used for bonding aerospace components is investigated. Previous investigations have proven that the use of high temperatures not only reduces the curing time but also increases the void formation. This phenomenon takes place due to evaporation of volatiles at high temperatures and affects the mechanical performance of the bonded joint. In this study a dual step cure process is investigated, where the curing temperature is increased depending on the degree of cure of the paste adhesive. In this context, the impact of increasing the temperature at different stages of the curing reaction is analyzed, determining a strategy to accelerate the curing reaction without major void formation. By this approach, the curing time of the paste adhesive used for this investigation could be reduced from 4 h to 30 min without decreasing the mechanical performance of the bonded joint.