Tests of laser welding aluminium tubes to aluminium sheets have confirmed that less energy is needed compared to welding copper tubes to aluminium sheets. Process times have been reported to be reduced with as much as 20-25%. Welding aluminium to aluminium, without any bimetallic effects, means that the connection becomes significantly stronger than when welding aluminium to copper.
Ultrasonically welding copper tubes to aluminium sheets is delicate and difficult, and so far only the very best ultrasonic welders have managed to weld the two materials together. This has kept many absorber manufacturers from switching to aluminium sheets and continue to produce expensive all copper absorbers. With the introduction of aluminium tubes, absorber manufacturers with ultrasonic welding equipment may also switch to aluminium sheets without having to change welding equipment. Thus, aluminium tubing offers cost and weight savings of the entire absorber to customers who weld absorbers ultrasonically.
- Continuous step welding (CSW)
CSW is a new welding technology that uses very low amounts of energy and also deformes the tubes to introduce turbulence. Hydro's HyLife™ Solar aluminium tubes have also been tested in this joining technology, with excellent results.