Interaction of {11■2} twin variants in hexagonal close-packed titanium
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2019年第4期
论文作者：Xiaocui Li Jingwei Li Bo Zhou Mingchao Yu Manling Sui
文章页码：660 - 666
摘 要：As multiple{11■2}twin variants are often formed during deformation in hexagonal close-packed （hcp）titanium, the twin-twin interaction structure has a profound influence on mechanical properties. In this paper, the twin-twin interaction structures of the{11■2}contraction twin in cold-rolled commercial purity titanium were studied by using electron backscatter diffraction （EBSD） and transmission electron microscopy （TEM）. Formation of the{11■2}twin variants was found to deviate the rank of Schmid factor,and the non-Schmid behavior was explained by the high-angle grain boundary nucleation mechanism.All the observed twin-twin pairs manifested a quilted-looking structure, which consists of the incoming twins being arrested by the obstacle twins. Furthermore, the quilted-looking{11■2}twin-twin boundary was revealed by TEM and high resolution TEM observations. De-twinning, lattice rotation and curved twin boundary were observed in the obstacle twin due to the twin-twin reaction with the impinging twin. A twin-twin interaction mechanism for the{11■2}twin variants was proposed in terms of the dislocation dissociation, which will enrich the understanding for the propagation of twins and twinning-induced hardening in hcp metals and alloys.
Xiaocui Li，Jingwei Li，Bo Zhou，Mingchao Yu，Manling Sui
Institute of Microstructure and Property of Advanced Materials,Beijing University of Technology
摘 要：As multiple{11■2}twin variants are often formed during deformation in hexagonal close-packed （hcp）titanium, the twin-twin interaction structure has a profound influence on mechanical properties. In this paper, the twin-twin interaction structures of the{11■2}contraction twin in cold-rolled commercial purity titanium were studied by using electron backscatter diffraction （EBSD） and transmission electron microscopy （TEM）. Formation of the{11■2}twin variants was found to deviate the rank of Schmid factor,and the non-Schmid behavior was explained by the high-angle grain boundary nucleation mechanism.All the observed twin-twin pairs manifested a quilted-looking structure, which consists of the incoming twins being arrested by the obstacle twins. Furthermore, the quilted-looking{11■2}twin-twin boundary was revealed by TEM and high resolution TEM observations. De-twinning, lattice rotation and curved twin boundary were observed in the obstacle twin due to the twin-twin reaction with the impinging twin. A twin-twin interaction mechanism for the{11■2}twin variants was proposed in terms of the dislocation dissociation, which will enrich the understanding for the propagation of twins and twinning-induced hardening in hcp metals and alloys.
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