Plastic deformation behavior and operative slip systems in Ni{sub 3}Nb single crystals
Temperature and orientation dependence of yield stress and operative slip system in Ni{sub 3}Nb single crystals were examined. Four slip systems of (010)[100], (001)[100], {l_brace}201{r_brace}(10{bar 2}) and (010)[001] and three twinning systems of {l_brace}011{r_brace}{l_angle}0{bar 1}1{r_angle}, {l_brace}211{r_brace}{l_angle}{bar 1}{bar 0} 7 13{r_angle} and {l_brace}012{r_brace}{l_angle}0{bar 2}1{r_angle} were activated depending on the crystal orientation and tested temperature. Anomalous strengthening was observed for some orientations where (010)[100] or {l_brace}201{r_brace}{r_angle}10{bar 2}{r_angle} slip was operative. A remarkable increase in the critical resolved shear stress (CRSS) for the (010)[100] slip occurred over a wide temperature range from {minus}196 to 800 C. the CRSS did not satisfy Schmid's law and the strain rate sensitivity of flow stress at a small plastic strain was negligible between room temperature and 700 C where an anomalous stress increase occurred. The anomalous strengthening mechanism in Ni{sub 3}Nb crystals deformed by [100] dislocations was discussed on the basis of anisotropy of APB energy on (010) and (001) in analogy with that in Ni{sub 3}Al with the L1{sub 2} structure.
- Research Organization:
- Osaka Univ. (JP)
- OSTI ID:
- 20034182
- Journal Information:
- Acta Materialia, Vol. 48, Issue 7; Other Information: PBD: 19 Apr 2000; ISSN 1359-6454
- Country of Publication:
- United States
- Language:
- English
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