Experimental investigation of the effect of ultrasonic welding parameters on the strength and weldability of GF/PA6 thermoplastic composites

In this article, ultrasonic welding of thermoplastic composites has been studied with an emphasis on weldability and joint quality evaluation, heat generation and joint formation, and the effect of welding force, vibration amplitude, fiber direction, horn displacement has been investigated. In this research, composites including PA6 and unidirectional pre-impregnated glass fibers, in two types of lay-outs (90/90/0/0)s and (0/90/-45/45/90/0)s with an energy director of flat shape with a thickness of 0.14 mm. Three vibration amplitudes of 51.8, 74.5 and 86.2 μm and welding force of 300, 500 and 1000 N with three welding times of 300, 500 and 900 ms are considered. The results of the test show that the highest welding strength of 25.5 MPa was obtained, which occurs in the vibration amplitude of 86.2 μm and the welding force of 500 N and the welding time of 500 ms. It can also be seen that the amount of maximum power consumption is affected by vibration amplitude and welding force, and by changing the direction of the fibers of the first layer of the composite from 90 degrees to 0 degrees, the welding strength increases more than twice.