High temperature plastic anisotropy in MoSi{sub 2} single crystals

Journal Article · Wed Feb 01 00:00:00 EST 1995 · Acta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-7151(94)00260-O· OSTI ID:27895

Maloy, S A; Mitchell, T E ^[1]; Heuer, A H ^[2]

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1. Los Alamos National Lab., NM (United States)
2. Case Eastern Reserve Univ., Cleveland, OH (United States)

The temperature dependence of the 0.2% yield stress in MoSi{sub 2} single crystals has been determined from 900 to 1,600 C for three specimen orientations, [001], [021] and [771]. Four different slip systems have been identified: {l_brace}013{r_brace}<100>, {l_brace}011{r_brace}<100>, {l_brace}1{bar 1}0{r_brace}1/2<111> and {l_brace}0{bar 1}3{r_brace}s1/2<331>; the critical resolved shear stresses (CRSS) of these systems differ significantly from one another. MoSi{sub 2} is especially strong in the [001] orientation at temperatures above 1,100 C, because decomposition of 1/2<331> dislocations forces slip on a fifth system, either {l_brace}12{bar 3}{r_brace}1/2<111> or {l_brace}0{bar 1}1{r_brace}1/2<111>. The CRSS of each slip system is discussed in terms of the influence of the dislocation core structure on the Peierls stress.

• OSTI ID: 27895
• Journal Information: Acta Metallurgica et Materialia, Vol. 43, Issue 2; Other Information: PBD: Feb 1995
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
MOLYBDENUM SILICIDES
YIELD STRENGTH
MICROSTRUCTURE
DISLOCATIONS
CRYSTAL STRUCTURE
SLIP
DEFORMATION
CRYSTAL LATTICES
STRESSES