Welding Aluminium Castings: Problems and Possibilities.

TIG and MIG welded joints have been tested between cast flat specimens, and between cast and sheet specimens. Cast alloys were 7% and 11% Si, 7% Mg, 5% ZnMg, 4% Cu. Sheet materials were AlSiMg, 4. 4 Mg and 4. 5 Zn plus Mg. Porous castings were prepared purposely to reproduce possible conditions encountered in practice. On sound castings, results were as good as on wrought material. On porous castings, serious defects arise in welded joints, which can only be reduced by preheating, increasing welding current and speed, and proceeding vertically from down to up.