TEM characterization of invariant line interfaces and structural ledges in a Mo-Si alloy
- Lawrence Berkeley Lab., CA (United States)
- Los Alamos National Lab., NM (United States)
- Case Western Reserve Univ., Cleveland, OH (United States)
Two distinct <1{bar 1}0> lath morphologies of Mo{sub 5}Si{sub 3} precipitates observed in MoSi{sub 2} differ in their cross-sectional shape and lattice orientation. Type I laths exhibit a rectangular cross section, with interfaces parallel to low-index planes, while Type II laths are parallelogram-shaped, with their major interface at 13{degree} to the Type I precipitate. The corresponding orientation relationships differ by a 1.8{degree} rotation around the lath axis. In this study, the difference between the two characteristic morphologies and orientation relationships is shown to be the formation of an invariant line strain for Type II precipitates. On an atomic scale, both interfaces have a terrace and ledge structure but differ in the stacking sequence of interfacial ledges associated with partial dislocations. The structural unit model and the invariant line model predict identical interface geometries which agree closely with the observations.
- Research Organization:
- Lawrence Berkeley Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 132769
- Report Number(s):
- LBL--37619; CONF-9506281--1; ON: DE96002444
- Country of Publication:
- United States
- Language:
- English
Similar Records
The invariant line and precipitate morphology in fcc-bcc systems
Structure and morphology of S-phase precipitates in aluminum