Control of 3003-H18 Aluminum Ultrasonic Consolidation

Ultrasonic consolidation of 150 mu m thick 3003-H18 aluminum foil to a 3003-H18 build plate has been investigated. The effects of the normal load, vibrational amplitude, and sonotrode velocity on consolidation quality as characterized by the total linear weld density (LWD) including both edge and edge defects were examined utilizing two sequential three-level full factorial design of experiments at a constant build plate temperature of 150 degrees C. These showed that the normal load and the vibrational amplitude have a significant influence on LWD, while the sonotrode rotational velocity has only a marginal effect. The formation of edge defects at the foil-build plate interface has been attributed to the nonuniform strain state across the foil width, while the central defects were related to sonotrode-foil contact pressure variations following the sonotrode pattern. In addition, LWD variations in +/- 10-20% were attributed to a nonuniform sonotrode-foil contact pressure distribution. Finally, representation of the total LWD as a function of the control parameters indicates that high total linear weld densities can be achieved with a control space bounded by high normal loads and intermediate to high vibrational amplitudes. Consideration of only central defects expands this control space allowing utilization of lower normal loads and vibrational amplitudes to achieve similar linear weld densities.