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A combination of experimental and numerical studies was carried out to understand the microstructure and formation mechanism of kink bands in α / β two-phase titanium alloys. A deformation kink band was introduced in a Ti-9Cr alloy after uniaxial compression test. The strength changes of the α and β phases inside and outside the kink band were evaluated by nanoindentation tests. A potential hardening effect was revealed in the α phase inside the kink band, while a possible softening effect was located in the β phase at the kink boundaries. Microstructural examination of the kink band was conducted by electron backscatter diffraction measurement. The crystal rotation axis was found to be perpendicular to both the (0001) basal plane of the α phase and one of the (110) planes of the β phase. The crystallographic features were characterized by transmission electron microscopy observation, revealing a prismatic 〈 a 〉 slip that occurred during the compression to accommodate the rotations around the c-axis. Nanoindentation tests were performed on an undeformed specimen to calibrate the crystal plasticity model. A crystal plasticity finite element model was developed and {110} β -rotation-type kink bands were reproduced in the simulation and confirmed the prismatic slip activity. • During the uniaxial compression test, kink deformation was revealed in the α/β titanium two-phase alloy Ti-9Cr. • EBSD measurements, nanoindentation tests, and TEM observations were carried out on the deformed grain. • The rotation axis was found normal to the (0001) basal plane and one of the common (110) β planes. • The kink deformation was initiated by an intragranular crystal rotation accommodated by prismatic dislocations. • In the CPFEM simulation, the deformation kink bands were reproduced and confirmed the prismatic slip activity. [ABSTRACT FROM AUTHOR]

The plastic deformation of an α / β two-phase Ti-10Cr alloy with fine lamella microstructure was investigated under uniaxial compression. The material was composed of coarse equiaxed β grains with { 332 } 〈 113 〉 twins introduced by cold rolling and α precipitates after aging. The crystallographic relationship between the matrix, the twin, and the precipitates was analyzed. A combination of optical microscopy, scanning electron microscopy, and electron backscatter diffraction with energy-dispersive X-ray spectroscopy analyses was carried out to investigate the microstructure and plastic deformation behavior of the Ti-10Cr alloy. During uniaxial compression tests, { 110 } β - rotation-type kinks were located in the Ti-10Cr alloy. The crystallographic and kinematical relationships among the formed deformation bands were clarified with the rank-1 connection theory. [ABSTRACT FROM AUTHOR]