2002 Volume 20 Issue 1 Pages 32-37
In order to enable that butt welding of 0.3 mm ultra thin aluminum sheets by using commercially available TIG welders, the authors has conducted a series of experiments. In the experiments 2%ThO2-W electrode of small diameter in DCEN polarity and two thick copper plates contact with base metals are used. The welding speed of 1500-6000 mm/min was attained. The effects of the remodeled nozzle are also studied at the speed higher than 6000 mm/min in the previous papers. This paper describes the new type of electrode shapes and the inclination of the torch. First the experiment with the electrode tip of conical shape with angle from 45° to 120° are conducted and the welding speed up to 6000 mm/min can be obtained, but the welding speed of 12000 mm/min can be done only for the electrode of conical angle 30°. The experiments with the electrode tip of conical and hemisphere shape show that the shape with a certain ratio of conical and spherical shape is suitable for the high spped 12000 mm/min welding. For the inclination of the torch we found it is better to decline so that the tip comes backward. By the combination of inclined torch and the electrode with a small spherical shape, high speed welding can be attained for the wide range of welding current.