Metallurgical phenomena play a profound role in the manufacture and application of zirconium and zirconium alloys. Very strong anistropy resulting from the hexagonal crystallization and a tendency for a preferred orientation of the crystals in wrought forms combine with an allotropic transformation at about 1600°F to make the metallurgy quite interesting. The common alloys are of the alpha plus intermetallic compound type and feature large two-phase regions with properties very much dependent on the thermomechanical working sequence used to make the product.