Smart SusceptorTM for Agile Bonding Repairs

Naval composite aircraft require heating blanket technology for structural repairs. Resistive heating blankets often have non-uniform heating due to heat sinks, especially at the blanket edges, which results in improperly completed repairs and premature failure and/or damage of bonded parts. The Navy would like an improved heating blanket technology that will increase temperature uniformity during a bonding application. CRG proposes to use a Heatcon Smart SusceptorTM system to demonstrate efficient, uniform heating capabilities on a representative article simulating a radome window repair. Smart SusceptorTM blankets utilize inductive heating and have a passive self-leveling capability at selectable temperature ranges. Once the wire reaches the specified temperature, the Curie point, the wires magnetic susceptibility reduces, therefore becoming less efficient at inductive heating. Functionally, this means that the hot regions of a blanket stop heating, while the cold regions of the blanket continue heating, resulting in a much more uniform overall blanket temperature regardless of the substrate complexity. The specific temperature range can be tailored by choosing an appropriate alloy, informed by composite material chemistry. In Phase I Base, CRG will construct test articles that mimic the material class, geometry, and size of a radome window repair. CRG will source Heatcon Smart SusceptorTM blankets and resistive blankets of various sizes, as well as renting a resistive bonder. The Smart SusceptorTM blankets will be designed to utilize an alloy that targets a 400 degrees Fahrenheit cure. Using the Smart SusceptorTM rack system that CRG currently owns and the smart susceptor blankets, CRG will conduct cure trials on the representative composite article. This cure will consist of a dwell at 365 degrees Fahrenheit for up to five hours, and a dwell at 400 degrees Fahrenheit for up to four hours. The same tests will be conducted using the resistive system as a comparative baseline. During testing, temperature data and infrared images will be collected and analyzed. CRG expects the Smart SusceptorTM system will show much more uniform temperature distribution all the way out to the blankets edges. In the Phase I Option, and Phase II, CRG will refine the Smart SusceptorTM blanket designs and prepare for live demonstrations of a radome window repair at a Navy facility.