Beneficial use of hyperbaric process conditions for welding of aluminium and copper alloys

Abstract

The joining of components with as few weld layers as possible is an important aspect of weld seam design due to the resulting reduced manufacturing effort and reduced influence of thermal cycles on the base material as well as reduced distortion. For materials with good thermal conductivity, this is not easily possible. The energy density of the arc has been found to be the core parameter for determining the penetration. In the present work, it is shown how the use of a hyperbaric process environment (2 to 16 bar) allows an increase of the energy density of the arc and thus an increase of the penetration depth for selected aluminium and copper alloys. Furthermore, the effects of this novel approach on weld metal metallurgy are presented. It is shown that the penetration depth can be doubled by increasing the ambient pressure. Furthermore, a statistical model for the prediction of the penetration depth depending on the welding parameters will be presented.

Beneficial use of hyperbaric process conditions on the welding of high-strength low alloy steels

“…These results and findings from studies with aluminum 17 , 28 , a local maximum for the welding depth as a function of welding voltage and welding current, can be assumed and will form beyond the test area shown, Fig. 7 .…”

“…As the pressure increases, the welding depth increases. However, the effect is not as pronounced as with the aluminum alloy presented in 17 . These results are supported by findings from Xue et al presented in 27 .…”

“…This arc also leads to a more finger-shaped bead geometry and can lead to the usage of smaller angles in weld seam preparation, which can lead to fewer layers that need to be welded for multirun welds 17 . To prove this, some single runs but welds of 15 mm sheets are presented in Sect.…”

“…The sample movement was carried out via a separately controlled linear moving table.

Figure 2 Scheme of the hyperbaric chamber 17 .

Figure 3 Welding chamber 17 .

…”

“…In addition, the range of materials included in the various investigations is also becoming increasingly broad. For example, the welding of copper or aluminum alloys 17 and duplex stainless steels 18 , 19 under hyperbaric process conditions has been investigated. For aluminum alloys, a beneficial usage of hyperbaric welding in the lower pressure ranges up to 10 bar can be assumed for the reduction of pores, a key problem regarding the welding of aluminum 17 .…”