EVALUATION OF MATERIALS FOR COMPOSITE REPAIR APPLICATIONS

There are many adhesives and resins available for repair of composite aircraft structures. The selection of repair materials is based on sev eral requirements, including the type of structure being repaired, str uctural loads, thermal stability, and process limitations of the mater ial and structure. The Navy's requirement for performing repair action s at remote locations has placed a number of additional constraints on materials being developed for repair applications. Specifically, Navy field repair requirements impose the need for materials that are stor able at ambient temperatures, processable with vacuum bag/heat blanket repair equipment, similar in mechanical properties to production mate rials, and compatible with field-level maintenance personnel capabilit ies and training. Developmental efforts at the Naval Air Warfare Cente r supporting naval aircraft in the fleet led to the evaluation of seve ral materials for repair of complex shaped graphite/epoxy structures. The repair applications include structural bonding, wet lay-up patches , honeycomb core splicing, back side sealing, and filling small scratc hes. A series of materials supplied by Magnolia Plastics, including Ma gnobond 6362, 6367, 6371, 6391, 6392, 6396 and 6398, was tested to det ermine compatibility with repair procedures, mechanical strength, and thermal stability in an 82 degrees C (180 degrees F) hot-wet environme nt. Results of the evaluation and potential applications for the mater ials are presented.