کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1578200 1001200 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Pseudoelasticity of Cu–Al–Be single crystals: Unexpected mechanical behavior
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
Pseudoelasticity of Cu–Al–Be single crystals: Unexpected mechanical behavior
چکیده انگلیسی

The pseudoelastic behavior of Cu–Al–Be single crystals shape memory alloys was analyzed in the temperature range from 303 K to 393 K. Tensile tests performed at slow crosshead speed show a dependence of the hysteresis associated to the stress induced β-18R transformation with temperature. The critical stresses of the β-18R transition have been determined giving a negative curvature parabolic dependence on temperature. The effect is more noticeable for the retransformation stress and a consequent increment in the stress hysteresis with temperature is observed. The deformation associated to the stress induced β-18R transition has also been found to depend on temperature. These singular features associated with the pseudoelastic behavior of Cu–Al–Be single crystals have been rationalized in terms of a structural distortion of the 18R martensite that has been found to occur in the considered temperature range. The strain associated to the structural distortion was determined as well as the dependence of its critical stress on temperature. The resulting entropy change was thus calculated, resulting fifty times smaller than the entropy change between the bcc parent phase and 18R. The possible mechanisms responsible of this structural distortion of the 18R structure are discussed.


► Cu–Al–Be single crystals show unexpected mechanical behavior.
► The stress hysteresis of the β-18R transition increases with test temperature.
► The pseudoelastic deformation increases with temperature.
► A structural distortion of the 18R martensite was detected under applied stress.
► Stresses to transform bcc into martensite do not depend linearly with temperature.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 528, Issue 27, 15 October 2011, Pages 7871–7877
نویسندگان
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