Effects of Strain Rate and Texture on the Tensile Behavior of Pre-strained NiCr Microwires
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2018年第2期
论文作者：周秀文 QI Yidong LIU Xudong NIU Gao YANG Bo YANG Yi ZHU Ye YU Bin 吴卫东
文章页码：459 - 465
摘 要：The stress–strain behavior and strain rate sensitivity of pre-strained Ni80Cr20（Ni20Cr） were studied at strain rates from 4.8×10–4s–1 to 1.1×10–1s–1. Specimens were prepared through cold drawing with abnormal plastic deformation. The texture of the specimen was characterized using electron backscatter diffraction. Results revealed that the ultimate tensile strength and ductility of the pre-strained Ni20Cr microwires simultaneously increased with increasing strain rate. Twinning-induced negative strain rate sensitivity was discovered. Positive strain rate sensitivity was present in fracture flow stress, whereas negative strain rate sensitivity was detected in flow stress values of σ0.5% and σ1%. Tensile test of the pre-strained Ni20Cr showed that twinning deformation predominated, whereas dislocation slip deformation dominated when twinning deformation reached saturation. The trends observed in the fractions of 2°-5°, 5°-15°, and 15°-180° grain boundaries confirmed that twinning deformation dominated the first stage.
周秀文1,2，QI Yidong1,3，LIU Xudong1，NIU Gao1，YANG Bo1，YANG Yi1，ZHU Ye1，YU Bin1，吴卫东1,2
1. Research Center of Laser Fusion,China Academy of Engineering Physics2. Institute of Atomic and Molecular Physics,Sichuan University3. State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials,Southwest University of Science and Technology
摘 要：The stress–strain behavior and strain rate sensitivity of pre-strained Ni80Cr20（Ni20Cr） were studied at strain rates from 4.8×10–4s–1 to 1.1×10–1s–1. Specimens were prepared through cold drawing with abnormal plastic deformation. The texture of the specimen was characterized using electron backscatter diffraction. Results revealed that the ultimate tensile strength and ductility of the pre-strained Ni20Cr microwires simultaneously increased with increasing strain rate. Twinning-induced negative strain rate sensitivity was discovered. Positive strain rate sensitivity was present in fracture flow stress, whereas negative strain rate sensitivity was detected in flow stress values of σ0.5% and σ1%. Tensile test of the pre-strained Ni20Cr showed that twinning deformation predominated, whereas dislocation slip deformation dominated when twinning deformation reached saturation. The trends observed in the fractions of 2°-5°, 5°-15°, and 15°-180° grain boundaries confirmed that twinning deformation dominated the first stage.
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