Pseudo-twinning in a deformed Nb-15Al-25Ti B2 alloy
- Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering
An alloy with nominal composition of Nb 15Al-25Ti (in at.%) has been developed for high temperature structural applications. This alloy exhibits a B2 ordered structure in the as-cast form. In addition to dislocation slip, pseudo-twinning occurs in this B2 alloy when deformed in compression at room temperature at a strain rate of {approximately}10{sup {minus}4} sec{sup {minus}1} to 3% strain. The pseudo-twinning plane has been deduced to be the {l_brace}112{r_brace} planes, which is similar to that in twinning of bcc metals. The mechanism of deformation pseudo-twinning in this B2 alloy is found to be analogous to the normal twinning mechanism in bcc metals, involving glide of partial dislocations with Burgers vector (b) given by b= 1/6{l_angle}111{r_angle} on {l_brace}112{r_brace} planes. This pseudo-twinning mechanism causes a phase transformation from the B2 to an ordered orthorhombic structure.
- OSTI ID:
- 72559
- Report Number(s):
- CONF-941144--; ISBN 1-55899-265-0
- Country of Publication:
- United States
- Language:
- English
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