Defects and site occupancies in Nb-Cr-Ti C15 Laves phase alloys
A multiply-faulted dipole in the C15 Laves phase of composition Nb{sub 15}Cr{sub 68}Ti{sub 17} has been characterized. The dislocations all lie along [011] and show no residual contrast when imaged edge-on at B = [0{bar 1}{bar 1}] indicating that they are edge in character. Given this, the Burgers vectors for the Shockley partials are {+-} 1/6[2{bar 1}1] and those of the stair-rods are {+-} 1/6[0{bar 1}1]. This is consistent with a g {center_dot} b analysis which was performed. The stacking fault energy was determined to be 35 mJ/m{sup 2} which is higher than the experimental value of 25 mJ/m{sup 2} from NbCr{sub 2}. Simulations are currently underway to understand, given the site occupancies and observed trend in stacking fault energy, whether Ti would be expected to raise the stacking fault energy of the C15 Laves phase.
- Research Organization:
- Los Alamos National Lab., Materials Science and Technology Div., NM (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 674971
- Report Number(s):
- LA-UR--98-873; CONF-980202--; ON: DE98006298
- Country of Publication:
- United States
- Language:
- English
Similar Records
Site occupancies in ternary C15 ordered Laves phases
Defects and site occupancies in Nb-Cr-Ti C15 Laves phase alloys