Original Date: 04/26/2004
Revision Date: 01/18/2007

United Defense, L.P. Armament Systems Division Aberdeen switched from gas metal arc welding-pulsed to laser welding for its Mk 25 missile canisters, resulting in improved weld quality and cost savings. The use of laser welding also reduced bowing and twisting of the canisters.

Prior to 2002, United Defense, L.P. Armament Systems Division (UDLP ASD) Aberdeen used gas metal arc welding-pulsed (GMAW-P) to weld the Mk 25 missile canisters. This process resulted in distortion, bowing, and twisting due to the high heat input, which caused difficulty in assembling them into a quad pack and did not allow interchangeability of the canisters. To address the distortion issue, UDLP ASD Aberdeen changed to laser welding and adapted an existing robot cell to save time and money. Operators were already familiar with the machinery and programmed and tested the system. A laser seam finding system was also installed, which locates the joints by measuring differences in heights using a laser beam.

Laser welding is low maintenance, has a low cost of operation, and is user friendly. Additionally, it has a high divergence rate, which increases safety. A fill wire feeder was added to the system because of strict undercut requirements. The laser has nine kilojoules of heat input versus 20 to 30 kilojoules from the GMAW-P, which alleviates the distortion difficulties. The system also gives a reduced weld size and reduces the use of filler metal. The filler metal reduction resulted in saving $75,000 in the first year of use. Additional benefits for the Mk 25 canisters include overall increased weld quality and decreased filter wire usage and rework time.

For more information see the Point of Contact for this survey.