Figure P7.3 (a) Ni ingot (b) Ni ingot Figure P7.4 welding direction pulsed arc weld Figure P7.5 7.3 Gutierrez and Lippold (23) made a preweld in aluminum alloy 2195 and then a test weld perpendicular to it, as shown in Figure P7.3. (a) Do you expect to see a nondendritic equiaxed zone near the fusion boundary of the test weld in the overlap region and why or why not? (b) Same as (a) but with the workpiece and the preweld solution heat treated before making the test weld. 7.4 Part of a pure Ni ingot with large columnar grains is welded perpendic ular to the grains, as shown in Figure P7.4. Sketch the grain structure in the weld. 7.5 A pulsed arc weld is shown in Figure P7.5. Sketch the grain structure in the area produced by the last pulse.