Observations on remarkable texture in cast zinc

New experiments have shown that the texture at the surface of cast zinc is much stronger and also more complex than previously reported. An extremely sharp basal texture, ~1200 x-random, co-exists with other randomly oriented crystals. Grains of both families are similar in size. We deduce that neither oriented nucleation nor oriented growth can account for this behaviour. The basal texture grains are invariably found directly adjacent to the free surface and we propose that any initially solidified plate-like dendrites contacting the melt surface are pulled into their final orientation through the action of surface tension.