Strain energy criterion of martensitic transformation. Technical report. [Ti alloys]

Technical Report · Thu Apr 01 04:00:00 EST 1976

OSTI ID:7251892

Shibata, M; Ono, K

A new theory of martensitic transformation based on the minimization of total strain energy has been developed, where the plastic relaxation strain (PRS) concept is introduced in order to relieve the high internal stress due to martensitic transformation in Ti, Ti-Mn, -Cr, -Ta, and -Zr alloys. For the analysis of Ti martensite, a total of 84 glide and twin systems were evaluated as PRS. For oblate spheroids with aspect ratio less than 0.01, (1,0,-1,1) =-1,0,1,2+ twin, (1,0,-1,1) =-1,-1,2,3+ glide and (1,1,-2,2) =-1,-1,2,3+ glide or twin systems produced strain energy minima at shear strain less than 2%, although crystal plasticity data of Paton and Backofen rules out the latter twin system. Theoretical predictions on habit plane in Ti, Ti-Ta and -Zr alloys turned out to be close to (334) sub B. In Ti-Mn and -Cr alloys, both (334) sub B and (344) sub B habit planes were predicted depending on the variant of (1,0,-1,1) =-1,0,1,2+ twin. These and other predictions are in excellent agreement with experimental observations. (GRA)

• Research Organization: California Univ., Los Angeles (USA). Dept. of Materials
• OSTI ID: 7251892
• Report Number(s): AD-A-023781
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
CARBON ADDITIONS
CHROMIUM ALLOYS
ELEMENTS
IRON ALLOYS
MANGANESE ALLOYS
MARTENSITE
METALS
PHASE TRANSFORMATIONS
TANTALUM ALLOYS
TITANIUM
TITANIUM ALLOYS
TRANSITION ELEMENTS
TWINNING
ZIRCONIUM ALLOYS