A synchrotron X-ray and electron backscatter diffraction based investigation on deformation and failure micro-mechanisms of monotonic and cyclic loading in titanium

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:726

Article

Ghosh, Atasi¹  Brokmeier, Heinz-Guenter^2,3  Al-Hamdany, Nowfal²  Sinha, Subhasis¹  Schell, Norbert³  Gurao, Nilesh¹ 

[1] IIT Kanpur, Dept Mat Sci & Engn, Kanpur 208016, Uttar Pradesh, India

[2] Tech Univ Clausthal, Inst Mat Sci & Engn, Agricolastr 6, D-38678 Clausthal Zellerfeld, Germany

[3] Helmholtz Zentrum Geesthacht, Max Planck Str 1, D-21502 Geesthacht, Germany

关键词: Titanium;    Texture;    Dislocation density;    Synchrotron X-ray;    EBSD;   

DOI  :  10.1016/j.msea.2018.04.036

来源: Elsevier

【 摘 要 】

Synchrotron X-ray diffraction technique has been used to estimate defect structure in terms of dislocation density, crystallite size and micro-strain in commercially pure titanium subjected to tension and cyclic deformation in stress and strain control mode. Statistical analysis of micro-texture data collected from electron backscatter diffraction approximately from the same region as that of synchrotron X-ray has been used to correlate orientation dependent micro-strain and dislocation density with deformation microstructure and microtexture. Two different orientations, namely, A with prismatic-pyramidal and B with basal orientation along the loading axis has been considered. Weak initial texture yet significant anisotropy in hardening/softening response and failure mode for monotonic tension and cyclic loading paths has been observed. Higher strain hardening response of orientation A during monotonic tensile deformation can be attributed to the evolution of lower micro-strain on basal orientation grains i.e, < 0002 > IIND along with extensive multi-variant twinning that also restricts crack propagation and delays failure in stress control mode. On the other hand, in strain control mode, orientation B shows higher fatigue life due to the generation of lower micro-strain in the basal orientation grains and single variant twinning that can undergo detwinning easily is responsible for delayed crack nucleation and subsequent failure.

【 授权许可】

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