Weld ability of dissimilar material of 304 stainless steel and polyethylene terephthalate

ABSTRACTGas tungsten arc welding was used to join dissimilar materials: 2-mm-thick plate of 304 stainless steel and 1.5-mm-thick polyethylene terephthalate (PET) plastic sheet. The joints of 30 mm in width possessed strong tensile shear loads of approximately 2.1 kN at the maximum and the tensile strength is 47.6 Mpa, which is almost the similar to shear load and tensile strength of the pure PET (the strength of PET is about 45 Mpa). The effect of main process parameters on the joint strength was investigated through experiments. It is found that appropriate amount of small bubbles is helpful to improve the strength of the joint. The infrared spectra analysis and energy-dispersive spectrometer results of the joints demonstrated that 304 and PET were bonded together through the reaction of carbonyl and metallic element in the joint, which lead to the, the chemical bond formation and the resulted in significantly improved joint strength.