Structure and Phase Composition of Heat Treated Al – Zr Bimetal

Special features of structural and phase transformations occurring in annealing of an explosion-welded Al – Zr bimetal are considered. It is shown that heat treatment causes formation and growth of an intermetallic layer on the interface, which has a hardness of 9 GPa. The methods of microscopic x-ray spectrum analysis and of phase analysis with the use of synchrotron radiation are used to show that the intermetallic layer is represented by a ZrAl 3 phase with a D0 23 -type structure. The lattice constants of this phase vary gradually from the metal-intermetallic interfaces to the center of the layer. Quantum-chemical modeling by the method of density functional is used to show that the zirconium trialuminide is in the steadiest state at a certain distance from the interface due to the process of secondary recrystallization and the accompanying annihilation of crystal structure defects.