The dendrites in the weld zone are found to be very fine and equiaxed in the weld interior and to be slightly coarser and columnar at regions adjacent to the weld line.
These differences in dendrite morphology can be seen more clearly in the higher magnification micrographs shown in Fig. 14b. Laser spot welds are found to be free from Heat Affected Zone (HAZ) micro-fissuring. It is observed from the figure that the HAZ is extremely narrow with no significant grain growth