YIELDING to recent intensive efforts of aircraft and equipment engineers, spotwelding - an old process - is being developed and refined to embrace new materials, higher speeds, stronger welds.
Results of these efforts will benefit not only aircraft manufacturers themselves, but will reach out into many industries entirely outside of the automotive field.
Four years ago spotwelding in aircraft construction was limited to one or two thicknesses of one or two materials. Today a modern landplane may have 15,000 to 20,000 welds in a dozen different thicknesses of twenty or more materials; a seaplane with spotwelded floats may have even more. Welding currents of 1000 to 50,000 amp. may be required, with welding pressures of 50 to 1500 lb. per sq. in. and accurately controlled periods of current duration from 0.01 to 0.10 sec. Welding set-ups may have to be changed several times per day, or even per hour. Unusual range and extreme flexibility are required to meet such production requirements.
This paper briefly outlines the fundamentals of spotwelding of aluminum alloys and corrosion-resistant steels, presents various examples of production-welded assemblies, discusses welding equipment, and touches upon production tooling.