Abstract
Measurements of the ultraviolet radiation from gas tungsten arc welding (GTAW) and gas metal spray arc welding (GMAW) of various alloys of aluminum and magnesium were made using a microcomputer controlled rapid scan spectroradiometer. Low concentrations of magnesium in aluminum were found to yield radiation of considerably greater biological activity than non-magnesium alloys and, at a distance of one meter from the arc, up to a thousand times that of sunlight at the earth's surface. The use of GMAW consumable electrode wire containing 5% magnesium led to an order of magnitude greater biological activity than non-magnesium wire. “Biological activity” in this regard refers to the effectiveness in producing skin-shielded DNA response, and as such may be related to the potential for carcinogenicity. Magnesium in small concentrations was found to be important to radiation emission owing to the ease of vaporization into the arc and to the existence of magnesium emissions in the ultraviolet. Emission dependencies on process, shielding gas, gap, and magnesium concentration in the base metal and consumable electrode wire were determined.