{l_angle}111{r_angle} Slip in NiAl single crystals between 4.2K and 100K
- Univ. of Oxford (United Kingdom). Dept. of Materials
- GE Aircraft Engines, Cincinnati, OH (United States). Engineering Materials Technology Labs.
- UES Inc., Dayton, OH (United States). Materials Research Division
Slip in {l_angle}111{r_angle} directions is a deformation mode found in many intermetallic compounds ordered into the B2 (CsCl) structure, but in NiAl it is active only under the limiting conditions of uniaxial loading along {l_angle}100{r_angle} and low testing temperatures. This paper investigates the deformation characteristics of {l_angle}100{r_angle} oriented NiAl tested between 4.2K and 300K. Compression tests have shown that below about 100 K, deformation takes place by slip in {l_angle}111{r_angle} directions without kinking, whereas between 100K and 300K kinking in the form of shearing on {l_brace}100{r_brace} becomes the dominant mode of plastic deformation, occurring usually near one or both ends of the compression samples. The yield stress has been found to exhibit a normal decrease with temperature, but at a rate that is smaller than most bcc metals. The sensitivity of the flow stress to strain-rate changes is also characteristically small, giving activation volumes around b{sup 3}, b being the Burgers vector of a{l_angle}111{r_angle} superdislocation. Both slip line observations and transmission electron microscopy have shown slip mainly on {l_brace}110{r_brace} near 80K, but with increasing activity on {l_brace}112{r_brace} and cross-slip between {l_brace}110{r_brace} and {l_brace}112{r_brace} with the lowering of temperature to 4.2K.
- OSTI ID:
- 78330
- Report Number(s):
- CONF-941144-; ISBN 1-55899-265-0; TRN: IM9531%%383
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 28 Nov - 9 Dec 1994; Other Information: PBD: 1995; Related Information: Is Part Of High-temperature ordered intermetallic alloys VI: Part 1. Materials Research Society symposium proceedings Volume 364; Horton, J. [ed.] [Oak Ridge National Lab., Oak Ridge, TN (United States)]; Baker, I. [ed.] [Dartmouth College, Hanover, NH (United States)]; Hanada, Shuji [ed.] [Tohoku Univ., Sendai (Japan)]; Noebe, R.D. [ed.] [NASA Lewis Research Center, Cleveland, OH (United States)]; Schwartz, D.S. [ed.] [McDonnell Douglas Aerospace, St. Louis, MO (United States)]; PB: 713 p.
- Country of Publication:
- United States
- Language:
- English
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