Parametric Studies on Thermoplastic Composite Welding for Aerospace Applications

The major limitations of thermoset polymers are their inability to be re-melted or recycled, shorter shelf-life, higher storage costs, and longer curing times thereby opening up opportunities for using thermoplastic based composites. Industries have turned their focus to thermoplastic composite materials because of their benefits such as Superior processability, Form freedom, Excellent mechanical performance at elevated temperatures, Excellent toughness, Very low moisture absorption, Outstanding chemical and solvent resistance, Indefinite shelf life at ambient temperature storage, and Excellent FST performance. Due to these benefits many airframe manufacturers and research institutes are initiated more research work on these high-performance thermoplastic composites. Using low melt PAEK (Poly Aryl Ether Ketone) polymer with carbon fiber (T700) prepreg the present experimental investigation was carried out to optimize process parameters for the autoclave consolidation and ultrasonic welding process for aerospace standard. Autoclave consolidated laminates were subjected to ultrasonic C Scan for the anomalies present in the laminates and qualified. Further, the manual hand-held ultrasonic gun was used for the fabrication of single lap joints (SLJ) specimens and similar configuration SLJ were fabricated by co-consolidation process using autoclave vacuum bag technique. These specimens were subjected to non-destructive evaluation of ultrasonic ‘C' scan. Subsequently these laminates were cut into specimens as per the ASTM standards and single lap shear strength was computed and presented here