Status on root cause investigation on airbag inflator failure mode

Fraunhofer ICT was approached by TAKATA Corporation to assist in investigations on unintended energetic disassembly of airbag inflators. Fundamental investigations on the AN based pyrotechnic main propellant revealed no problem with typical failure modes of pyrotechnic propellant e.g. phase stabilization of AN or chemical stability. Morphological changes and generation of pores in the core of the propellant grain were identified leading to an increased burn rate by so called porous burning mechanism. Additional investigations focused on characterization of moisture intrusion into the inflator and replication of moisture intrusion by environmental simulation programs used for product validation.