کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1575072 1514737 2014 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Microstructure and superplasticity of TA15 alloy
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
Microstructure and superplasticity of TA15 alloy
چکیده انگلیسی
Superplasticity of TA15 alloy was investigated by constant strain rate tensile method in this work. In order to enhance superplasticity, thermo-mechanical techniques were applied for refining the grains of the alloy first. The superplastic tensile tests were carried out on a SANS CMT4104 electronic tensile testing machine at temperatures ranging from 780 to 950 °C and strain rates from 3.3×10−4 to 1.1×10−2 s−1. The tensile elongation-to-failure values between 188% and 1074% were obtained. Microstructure evolution after superplastic deformation was also analyzed by optical microscope (OM) and transmission electron microscope (TEM). The micrographs show that the grains were coarsened after deformation, and α→β phase transformation took place at 950 °C, which resulted in the worst superplasticity. Extensive strain hardening stages were observed in the true stress-strain curves due to high dense dislocations in the thermo-mechanically processed alloy and dynamic grain growth during superplastic deformation. The strain rate sensitivity m and the activation energy values at various deformation conditions were calculated, respectively. Based on an analysis of the above studies, it may be inferred that grain boundary sliding (GBS) in TA15 alloy is accommodated by grain boundary diffusion at high temperatures and low strain rates, and the accommodation process involves dislocation glide creep at low temperatures and high strain rates.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 606, 12 June 2014, Pages 401-408
نویسندگان
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