The dislocation sub-structure evolution during hot compressive deformation of Ti-6Al-2Zr-1Mo-1V alloy at 800 °C

Hot compressive behaviors of Ti-6Al-2Zr-1Mo-1V alloy at 800 °C, as well as the evolution of microstructure during deformation process, were investigated. The experimental results show that flow stress increases to a peak stress followed by a decease with increasing strain, and finally forms a stable stage. Dislocations are generated at the interface of α/β phase, and the phase interface and dislocation loops play an important role in impeding the movement of dislocation. As strain increasing, micro-deformation bands with high-density dislocation are formed, and dynamic recrystallizaton occurs finally. XRD Fourier analysis reveals that dislocation density increases followed by a decrease during compressive deformation, and falls into the range from 10¹⁰ to 10¹¹ cm⁻².     

Precise determination of theα → α+β phase transformation temperature of Zr-1.0Sn-0.3Nb-0.3Fe alloy

In this investigation,differential scanning calorimetry(DSC) and metallographic experiments were performed to study α→α +β phase transformation temperature in a Zr-1.0Sn-0.3Nb-0.3Fe alloy.The deconvolution and extrapolation methods to determine the α→α+β phase transformation temperature in DSC experiment were appropriate for the Zr alloy.Moreover,precise determination of α→α+β phase transformation temperature was carried out by back-scattered electron imaging(BSEI) and electron back-scattered diffraction(EBSD) characterization techniques.The α→α+β phase transformation temperature of the Zr-1.0Sn-0.3Nb-0.3 Fe alloy was determined to be 765-770°C.