Microstructure and tensile properties of hot-rolled Zr50–Ti50 binary alloy

Abstract

A series of Zr50–Ti50 (at%) alloy specimens with different treatments was prepared. Tensile test, X-ray diffraction (XRD), optical microstructure, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses were performed to investigate alloy tensile properties and microstructure. Hot-rolling process was found to have a remarkable strengthening effect. The tensile strength of hot-rolled specimens had an increase of 37% compared with solution-treated specimen (undeformed). All specimens exhibited α′-Zr structures and similar microstructures. However, a significant plasticity difference was observed in the Zr50–Ti50 hot-rolled specimens with different cooling rates. Detailed TEM microstructural analysis showed that the morphology of twins in the hot-rolled specimens was different. Most of the twins were nano-twins. It was found that the twins had effective on Zr50–Ti50 alloy plasticity, in the meantime significant effects on tensile properties due to the complicated interactions between twin boundaries and dislocations. All these findings in this work may provide a new strengthening mechanism for Zirconium-based alloys.