Vibration Welding Scale Up - A Comparison of Laboratory and Industrial Components

The objective of this study was to compare mechanical properties of lab-scale vibration welded test specimens with those of a complex automotive component using several different materials. Different laboratory specimens (butt, Tee, cup-plate with/without flash trap) were made under different vibration welding conditions (weld pressure, meltdown) and then tested in tension. The tensile properties of the specimens were then compared with the burst pressure results from a prototype air intake manifold. 30% glass reinforced nylon 66 and polypropylene compounds were used. The lab scale specimens and manifolds showed similar trends: (i) all parts failed at the weld; (ii) increased weld pressure generally caused decreased weld strength (iii) meltdown was observed to have little effect on part strength (iv) the ratio of lab specimen strength to burst strength was comparable but not equal for the materials tested. Flash traps significantly affect weld strength when over filled. At low weld pressures, over filled flash traps decrease weld strength. At high pressures, over filled flash traps increase weld strength.