Ordered Zirconium Alloys with Intermetallic Hardening

This research article outlines a detailed study of mechanical properties of zirconium alloys in the Zr-8Al and Zr-8Al-1Nb systems using strain rate change measurements and tensile tests in a wide temperature range, to optimize their specific properties such as dislocation creep resistance, high temperature strength and low temperature ductility.In this approach, suitable combination of the innovative are melting, hot-working and annealing treatment of the Zr-8Al-1Nb alloy to produce a substantially continuous matrix of the L12 ordered intermetallic compound Zr3Al (up to 92%).A series of mechanical tests has been carried out with the Zr3Al based alloys which should consider as discontinuously reinforced composite materials by the very nature themselves.Post thermomechanical treatment of as-cast Zr3Al based alloys indicates owing to their unchangeable yield stress at 293 and 673-973 K. Mechanical properties of the essentially ordered Zr3Al based alloys are at least two times higher than that observed for solution hardened zirconium alloys (Zircaloys).The Zr3Al induced structure developed by thermomechanical treatments with subsequent annealing improves the chemical and structural homogeneity of the composite material as a whole.The formation of inhibitory jog type obstacles on the screw dislocations is assumed to be the rate controlling deformed mechanism of Zr3Al ordered alloy strengthening which is dependent on the dislocation density.The excellent combination of short-term mechanical properties at 293 K and relaxation strength at 673-773 K revealed in the Zr3Al based alloys leads to their ability for high performance applications in nuclear energetic.