Deformation and failure by weaving dislocation networks in body-centered-cubic tungsten

Cao，Hailin1; Lu，Wenjun1; Yi，Min2; Wang，Shuai1

2022-11-01

10.1016/j.matdes.2022.111182

Materials and Design   Impact Factor & Quartile

0264-1275

1873-4197

Dislocation is the primary carrier for accommodating plastic deformation in metals. It is generally envisaged that metals with low initial dislocation density have high strain-to-failure and good formability, and vice versa. However, contrary to most metals, body-centered-cubic pure tungsten becomes brittle after reducing its dislocation density by recrystallization, while its formability increases after heavy deformation. To elucidate the mechanism of this counterintuitive mechanical behavior, by combining ex-situ indentation tests and dislocation reconstruction techniques, we find that tungsten's deformation and failure processes are accompanied by the formation of a specific dislocation pattern. Dislocation networks are governed by a mechanism similar to the weaving process of the spider's orb web. After heavy deformation, subgrains are generated due to the weaving process. The recurring weaving of dislocations reduces the mean free path for crack propagation, which is considered as the main reason for the increased formability of tungsten after deformation.

Dislocation Fracture Subgrain boundary Tungsten Weaving mechanism

SCI

English

First ; Corresponding

[KQTD2 019 092 917 250 571] ; [GJHZ20200731095213039]

Materials Science

Materials Science, Multidisciplinary

WOS:000868293800002

ELSEVIER SCI LTD

2-s2.0-85139072605

Scopus

1.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,1088 Xueyuan Blvd,518055,China
2.State Key Lab of Mechanics and Control of Mechanical Structures & College of Aerospace Engineering & Institute of Frontier Science,Nanjing University of Aeronautics and Astronautics,Nanjing,210016,China

Cao，Hailin,Lu，Wenjun,Yi，Min,et al. Deformation and failure by weaving dislocation networks in body-centered-cubic tungsten[J]. Materials and Design,2022,223.

Cao，Hailin,Lu，Wenjun,Yi，Min,&Wang，Shuai.(2022).Deformation and failure by weaving dislocation networks in body-centered-cubic tungsten.Materials and Design,223.

Cao，Hailin,et al."Deformation and failure by weaving dislocation networks in body-centered-cubic tungsten".Materials and Design 223(2022).