Defects, deformation mechanisms and phase stabilities in Nb-based B2 compounds

Conference · Fri Dec 30 23:00:00 EST 1994

OSTI ID:72423

Hou, D H; Shyue, J; Yang, S S; Fraser, H L ^[1]

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1. Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

Deformation mechanisms have been determined for compounds based on Nb{sub 3}Al containing various additions of Ti. These compounds exhibit the B2 crystal structure and deform by activation of one or more of the following slip systems, namely {l_angle}111{r_angle}{l_brace}110{r_brace}, {l_angle}111{r_angle}{l_brace}112{r_brace} and {l_angle}111{r_angle}{l_brace}123{r_brace}. The dislocations are dissociated as superpartial pairs, each with Burgers vector, b, given by b=1/2{l_angle}111{r_angle}, which bound a ribbon of antiphase boundary. Attempts have been made to determine the ordering temperatures and the ordering energy of these compounds. Estimates of the site occupancy of these nonstoichiometric B2 compounds have also been determined by the ALCHEMI technique. The phase stabilities of these compounds have been determined over a wide range of temperatures and the effect of these on mechanical properties has been assessed.

• OSTI ID: 72423
• Report Number(s): CONF-9310224--; ISBN 0-87339-249-3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CHEMICAL COMPOSITION
COMPRESSION STRENGTH
CRYSTAL STRUCTURE
DEFORMATION
DISLOCATIONS
ELECTRON DIFFRACTION
INTERMETALLIC COMPOUNDS
MECHANICAL PROPERTIES
NIOBIUM ALLOYS
PHASE DIAGRAMS
PHASE STABILITY
PRECIPITATION
SLIP
TENSILE PROPERTIES
TITANIUM ALLOYS
TRANSMISSION ELECTRON MICROSCOPY