An Investigation into the Microstructural Response to Flexural Stresses of a Metastable -Phase Ti Alloy produced by Blended Elemental Powder Metallurgy

A Ti-10V-3Al-3Fe metastable & beta; Ti alloy is strained under three-point bending conditions according to the ASTM E290-14 standard. A combination of electron backscatter diffraction (EBSD) mapping and high-resolution scanning transmission electron microscopy (STEM) is used to investigate the microstructural response to flexural stress. Results reveal a delayed formation of the deformation products, due to the load-bearing capacity of the constituent voids. The deformation products are confined in narrow bands on either side of the fracture surface. {332}& LeftAngleBracket;113 & RightAngleBracket; twinning system is identified as the primary deformation mode followed by the formation of & alpha;& DPRIME; martensite both in & beta; matrix and & beta; twins. Accommodation of the microscopic strain arising from the development of & alpha;& DPRIME; structure and & beta;-twinning triggers the formation of fine deformation-induced & omega; plates, which are observed predominantly at the interfacial plane of & beta;/& beta;(twin) and & beta;/& alpha;& DPRIME;, and also in the interior of the & beta; twins.