An X-ray diffraction study of RST AlTiV alloys

Two phases were identified in both the binary and ternary alloys: fcc Al and bct Al sub 3 (Ti sub x V sub 1--x ). No other phases were observed despite the binary Al--V phase diagram having three phases of greater thermodynamic stability at temperatures < 736 deg C, i.e. Al sub 10 V, Al sub 7 V, and Al sub 6 V. Ostensibly, either Ti stabilizes the DO sub 22 structure or, the inherently sluggish kinetics of these peritectic reactions prevent their formation. Vanadium additions to binary Al--Ti alloys were found to produce dimensional changes in the crystal structure of the intermetallic phase. The lattice parameters of the intermetallics's bct unit cell were found to bary along a path connecting Al sub 3 Ti to Al sub 3 V. Therefore, V is believed to substitute for Ti and form Al sub 3 (Ti sub x V sub 1--x ). This ability to vary the unit cell of the intermetallic suggests the possibility of altering chemistry to effect changes in Al--intermetallic coherency. 9 ref.--AA