کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1580086 | 1645418 | 2009 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Structural inhomogeneity of metallic glass observed by ultrasonic and inelastic X-ray scattering measurements
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Structural inhomogeneity of metallic glass observed by ultrasonic and inelastic X-ray scattering measurements Structural inhomogeneity of metallic glass observed by ultrasonic and inelastic X-ray scattering measurements](/preview/png/1580086.png)
چکیده انگلیسی
The structural stability of metallic glasses is frequently deteriorated under ultrasonic perturbation at relatively low temperatures, e.g., near the glass transition temperature Tg, even for thermally stable Pd- and Zr-based metallic glasses. By a mechanical spectroscopy analysis, it is suggested that such an instability, i.e., crystallization, is caused by atomic motions associated with the (slow) βrelaxation, that are resonant with the ultrasonic-strain field. Furthermore, such atomic motions below Tg are considered to occur at weakly bonded regions in a nanoscale inhomogeneous microstructure of glass, which was intuitively inferred from a partially crystallized microstructure obtained by annealing a Pd-based metallic glass just below Tg under ultrasonic perturbation. On this basis, we proposed a structural model of metallic glasses that consists of strongly bonded regions surrounded by weakly bonded regions. To reveal the validity of the model, we have also employed the inelastic X-ray scattering technique to measure the sound velocity of nanometer wavelength of longitudinal acoustic phonons. We have found in a completely frozen Pd-based metallic glass that the velocity of nanometer wavelength exceeds ultrasound velocity of millimeter wavelength, which suggests that elastically harder nanoscale regions exist in the glass matrix.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volumes 521â522, 15 September 2009, Pages 236-242
Journal: Materials Science and Engineering: A - Volumes 521â522, 15 September 2009, Pages 236-242
نویسندگان
T. Ichitsubo, E. Matsubara,