Review of Factors Influencing Porosity in Aluminium Arc Welds

TWI Industrial Member Report Summary 625/1997

By A B D Gingell and T G Gooch

Background

It is well recognised that aluminium alloys are highly sensitive to the development of weld metal porosity, and indeed the problem may be more acute than in most other structural metals. The occurrence of weld metal porosity may directly affect the service properties of the completed joint and further may render it difficult or impossible to undertake reliable non-destructive testing for other types of weld flaws. It is therefore important to identify the controlling factors in order to minimise its occurrence in practice, and this review was undertaken to define the present understanding of the problem. Relevant published literature was surveyed with attention being paid to the mechanism of pore formation and to the influence of welding parameters.

Objective

To review published literature on porosity in aluminium alloy arc welds and assess the present level of understanding, so that recommendations can be made to minimise its occurrence during fabrication.