The metallographic section of the fuse holder reveals a single phase, fine grain size microstructure. At the highest magnification there is evidence of cold work (deformation at around room temperature), which is shown by the parallel sets of slip bands within the grains.

The fine microstructure was achieved by cold work, annealing and recrystallisation, but the final stage of deformation was not followed by an anneal. This left the material in a cold-worked state, which increases its strength above that achieved by the alloy composition.

See also:

• Composition
• Phase Diagram