In situ electron backscatter diffraction study of twinning in commercially pure titanium during tension-compression deformation and annealing. (15th February 2017)

• Record Type: Journal Article
• Authors: Sinha, Subhasis; Gurao, N.P.
• Is Part Of: Materials & design. Volume 116(2017)
• Page Start: 686
• Page End: 693
• Publication Date: 2017-02-15
• Subjects: In situ testing -- Electron backscatter diffraction -- Titanium -- Twinning; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.10.060
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Tension-compression forward and reverse loading followed by annealing at 773 K for 1 h was carried out on commercially pure titanium using an in situ heating stage with tensile testing facility in scanning electron microscope fitted with electron backscatter diffraction setup. Twins of four different variants were observed during tension in load control mode in a relatively large grain within the area of inspection. Morphology of the twins changed during subsequent deformation stages and un-indexed points within the twins decreased or increased which may be due to changes in dislocation density during unloading and compression loading stages. Reloading in tension caused barrelling of the twins. Some of the twins disappeared and new twins formed during annealing. Although all the variants show similar Schmid factor for extension twinning, there is variation in lateral thickening of different twin variants within the same grain which can be explained from variation in elastic modulus. It is also observed that twin intersections can play an important role in nucleation and growth of new twins. Graphical abstract: Highlights: Twinning-detwinning incorporates 'textural Bauschinger effect' in titanium. Multiple variant twinning is accompanied by marked increase in dislocation density in the microstructure. Previous twins disappear and new twins form during annealing of deformed titanium. Elastic modulus difference causes variation in growth of different twin variants. Twin intersections influence nucleation of new twins and growth of previous twins.