Deformation twinning of non-stoichiometric Ti{sub 3}Al alloy

Technical Report · Sun Dec 31 04:00:00 EST 1995

DOI:https://doi.org/10.2172/201768· OSTI ID:201768

Lee, J W; Hanada, S ^[1]; Yoo, M H ^[2]

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1. Tohoku Univ., Sendai (Japan). Inst. for Materials Research
2. Oak Ridge National Lab., TN (United States). Metal and Ceramics Div.

Non-stoichiometric Ti{sub 3}Al polycrystals with DO{sub 19} structure have been deformed in compression to a true strain of about 8% at temperatures ranging from 973 K to 1,373 K and at an initial strain rate of 1.3 x 10{sup {minus}4}/s. Deformation modes are observed focusing on twinning. It is found that deformation twinning of non-stoichiometric Ti{sub 3}Al occurs in the temperature range of 1,073 K to 1,373 K. Crystallographic characteristics of deformation twinning systems are revealed by optical and transmission electron microscopy and X-ray Laue method. it is shown that most deformation twins are macroscopically lens-shaped and their width is increased with increasing temperature. Also, the volume fraction of deformation twins is increased with increasing strain at 1,273 K and temperature in the range of 1,073 K to 1,273 K. A dominant deformation twinning system observed in the samples deformed at temperatures from 1,073 K to 1,373 K is identified as (11{bar 2}2)[11{bar 2}{bar 3}]. {l_brace}11{bar 2}4{r_brace} and {l_brace}10{bar 1}1{r_brace} twins are also operative with a low density.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 201768
• Report Number(s): CONF-9506209--2; ON: DE96005648
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CRYSTAL STRUCTURE
DEFORMATION
EXPERIMENTAL DATA
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 1000-4000 K
TITANIUM BASE ALLOYS
TWINNING
X-RAY DIFFRACTION