Thermal effects on the performance of ultrasonically welded CF/PPS joints and its correlation to the degree of crystallinity at the weldline

The effect of temperature on the lap shear strength (LSS) and failure mechanisms ultrasonically welded carbon fibre reinforced polyphenylene sulphide (CF/PPS) joints was investigated, correlating weld performance to crystallinity degree PPS at weldline. single-lap tests were carried out temperatures ranging from –50 °C 120 three series, one with amorphous two semi-crystalline overall trend decreasing LSS increasing largest reduction observed above glass transition temperature. Fractographic analysis revealed that main mechanism matrix fracture while fibre/matrix debonding became more pronounced It demonstrated higher weldline beneficial high (90 °C) most likely due interfacial compared PPS. shown be advantageous -50 °C, probably toughness ductility