The PIS (plastic instability stress) values for V, Nb, Mo, and Zr were about 390, 370, 510, and 170 MPa, respectively.

Plastic instability behavior of bcc and hcp metals after low temperature neutron irradiation

T. S. Byun^, , K. Farrell and N. Hashimoto

Oak Ridge National Laboratory, Metals and Ceramics Division, P.O. Box 2008, MS-6151, Oak Ridge, TN 37831-6151, USA

Available online 7 June 2004. 

Abstract

Plastic instability in uniaxial tensile deformation has been investigated for the body centered cubic (bcc) and hexagonal close packed (hcp) pure metals, V, Nb, Mo, and Zr, after low temperature (60–100 °C) neutron irradiation up to 0.7 dpa. Relatively ductile metals, V, Nb, and Zr, experienced uniform deformation prior to necking at low doses and prompt plastic instability at yield at high doses. Mo failed in a brittle mode within the elastic limit at doses above 0.0001 dpa. V showed a quasi-brittle failure at the highest dose of 0.69 dpa. In the ductile metals, plastic instability at yield occurred when the yield stress exceeded the plastic instability stress (PIS), which was nearly independent of dose. The PIS (plastic instability stress) values for V, Nb, Mo, and Zr were about 390, 370, 510, and 170 MPa, respectively. The coincidence of plastic instability at yield and dislocation channeling cannot be generalized for all metallic materials.

D0200; N0100; R0300

Article Outline

1. Introduction

2. Experimental

3. Result and discussion

3.1. Engineering stress–strain curve and plastic instability

3.2. Dose dependence of plastic instability stress

3.3. Channel deformation and plastic instability in V

4. Conclusions

Acknowledgements

References

Corresponding author. Tel.: +1-865 576 7738; fax: +1-865 574 0641

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Journal of Nuclear Materials Volumes 329-333, Part 2, 1 August 2004, Pages 998-1002 Proceedings of the 11th International Conference on Fusion Reactor Materials (ICFRM-11)