SBIR-STTR Award

Joining of thermoplastic matrix composites to form large panelsin structures by fastening, adhesive bonding or resistance inductionwelding produces joints that can be the "weak link" resulting in failure. Ahybrid technique involving a laser beam will be studied in this Phase Ieffort. The objective of this research is to metallurgically jointhermoplastic matrix composites such as PEEK reinforced with AS4, or IM7/IM 8 fibers using a rapid thermal processing (RTP), active-metal alloytechnique. These composites are expected to be used in several modules andcomponents such as fenders, doors, structural panels in automobiles andpackage housings for the electronics in many commercial and defensesystems. The joints produced using these methods are expected to be soundand result in components with high structural integrity. Destructive testsare proposed in Phase I to evaluate the joint quality and performance. Thismethod would allow for the introduction of intelligent manufacturingsystems that could facilitate the rapid production of large sizedpanels/joints at low costs. In Phase II, further refinement of theprocessing parameters is expected so that scale up to commercializationwould be feasible.

Joining of polymer matrix composites, such as carbon fiber/epoxy, to aluminum in order to form large panels in structures by fastening, adhesive bonding or resistance induction welding produces joints that can be the most challenging aspect of preparing such structures. The primary objective of this research is to formulate and customize a room temperature curing adhesive for specific use in mounting composite structures to aluminum. This will necessitate the experimentatian required to achieve a balance between adhesion, structural strength and shock-damping capability. In order to make such an adhesive ideally suited for in-field use, surface treatment evaluation with manual corona discharge preparation of the bond surfaces as well as ultrasonic non-destructive evaluation of such joints will be developed. By yhe end of Phase II, we plan to have a room curing adhesive as well as a customized NDE technique for measuring integrity of the adhesive bonds. This Phase II Project will result in the creation of an application-specific structural adhesive coupled with a surface preparation protocol for the optimization of the bonding, strength, impact resistance and ease of use for both in-field CAV repair and optimal performance. The OEM advantages of this adhesive will be its use in allowing for adhesive joints to be prepared between polymer composites and metals such as aluminum alloys where high impact is an anticipated hazard. This Phase II effort will provide a general methodology for the end-user to apply this adhesive system and simple surface preparation approaches without the constraint of specialized application and curing.