HOT WORKABILITY OF ALUMINUM AND ALUMINUM ALLOY INGOTS WITH FEATHER CRYSTALLITE STRUCTURE.

Hot workability of feather crystallite (F. C. ) ingots and granular crystallite (G. C. ) ingots was examined by dynamic and static tests to clarify the relation between the cast structure and the workability. Load-elongation curves obtained by the tension test showed a maximum at about 0. 3% of elongation. The resistance to compressive deformation in the heat flow direction of F. C. ingot was the lowest of all directions, and that of G. C. ingot was higher than F. C. ingot. The speed of extrusion products through die bearing at a constant pressure in the heat flow direction of F. C. was the fastest and that of G. C. ingot was the slowest. When the F. C. ingot was extruded in high-pressure, the feather crystallite structure changed in to granular grain structure, and the mechanical properties of extrusion products were the same as those of G. C. ingot.