Friction welding of polyamides

Abstract

Results from different experiments on friction welding are used to characterize the behavior of polyamide over a wide range of welding conditions. Several types and grades of polyamide were joined using the vibration and spin welding processes. The quality of the welds was evaluated by short time tensile tests and microscopy. In addition to the geometry of the parts being joined, the process parameters and the material were found to affect the quality of the weld, so that associated with each application is a different set of optimum welding parameters.

Welding and Joining of NiTi Shape Memory Alloys: A Review

“…Friction welding has several variants which are dependent on the processes and equipment involved: linear friction welding [60]; rotary friction welding [61]; spin welding [62]; inertia friction welding [63]; and friction stir welding [25]. From these, friction stir welding is the most recent and, as such, special attention has been devoted to this technique.…”

Fusion Bonding/Welding of Thermoplastic Composites

“…Fusion Bonding/Welding of Thermoplastic Composites strength of the joint can be attributed to the re-orientation of short glassfibers to the perpendicular direction of the load path during the weld process (see Figure 6) [12,20]. Re-orientation of the fibers to the perpendicular direction of the load path decreased the load transfer through the weld zone, resulting in the dramatic drop in strength.…”

“…By changing the material to a short glass-fiber reinforced PA composite, the weld strength dropped considerably in comparison with that of the corresponding parent material. A maximum weld strength of 44 MPa was achieved, which was 56% of the strength of the parent material (i.e., 79 MPa) and even less than the strength of un-reinforced PA (i.e., 55 MPa) [20]. The low weld Control System Figure 5.…”

“…For example, for un-reinforced polyamide (PA) at a welding pressure of 3-4 MPa and welding time of 4 seconds a maximum butt weld strength of 80-90% of corresponding parent material (i.e., 55 MPa) was achieved [20]. The same butt weld strength was obtained at the constant welding pressure of 7 MPa but with a welding time of 2 seconds [20]. Note that although the optimum welding pressure of 3-4 MPa was not applied, the same weld strength was obtained by adjusting the welding time for the second scenario.…”

“…By adjusting amplitude and frequency appropriately, the desired steady-state condition will be attained more rapidly, thereby, resulting in a shorter welding time. It should be noted that the selection and variation of welding frequency and amplitude depend on the limitations of the vibration machine and geometry of the parts [20].…”