Thermal stability of Cu/W nano-multilayers
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- 作者：F. Mosznera ; frank.moszner@gmail.com" class="auth_mail" title="E-mail the corresponding author ; frank.moszner@empa.ch" class="auth_mail" title="E-mail the corresponding author ; C. Cancellieria ; M. Chiodia ; S. Yoona ; D. Ariosab ; J. Janczak-Ruscha ; L.P.H. Jeurgensa
- 关键词：X-ray diffraction ; Microstructure ; Morphological stability ; Kinetic analysis ; Cu/W nano-multilayers
- 刊名：Acta Materialia
- 出版年：2016
- 出版时间：1 April 2016
- 年：2016
- 卷：107
- 期：Complete
- 页码：345-353
- 全文大小：3008 K
文摘
The thermal stability of Cu/W nano-multilayers in the temperature range of 400 °C– 800 °C has been investigated by high-resolution scanning electron microcopy, X-ray photoelectron spectroscopy and X-ray diffraction. A repetition of 100 alternating nanolayers of Cu and W with individual thicknesses of 5 nm were prepared by magnetron sputter deposition on an α-Al2O3 substrate. In the as-deposited state, the nano-multilayers exhibit pronounced Cu <111> and W <110> textures with a Cu{111}<10
>||W{110}<00> orientation relationship. Annealing at T ≥ 500 °C results in the appearance of a high number of line-shaped protrusions on the outer surface, which are composed of facetted Cu particles. Annealing at T ≥ 700 °C leads to a gradual degradation of the initial layered structure towards a spheroidized nanocomposite consisting of globular W particles embedded in a Cu matrix (after annealing at 800 °C). An average activation energy of 257 ± 21 kJ/mol (2.66 ± 0.22 eV) related to this degradation process is determined by in-situ high-temperature X-ray diffraction. The experimentally obtained activation energy indicates that the morphological transformation is governed by the diffusion of W along internal interfaces such as Cu/W interphase boundaries and W/W grain boundaries.
>||W{110}<00> orientation relationship. Annealing at T ≥ 500 °C results in the appearance of a high number of line-shaped protrusions on the outer surface, which are composed of facetted Cu particles. Annealing at T ≥ 700 °C leads to a gradual degradation of the initial layered structure towards a spheroidized nanocomposite consisting of globular W particles embedded in a Cu matrix (after annealing at 800 °C). An average activation energy of 257 ± 21 kJ/mol (2.66 ± 0.22 eV) related to this degradation process is determined by in-situ high-temperature X-ray diffraction. The experimentally obtained activation energy indicates that the morphological transformation is governed by the diffusion of W along internal interfaces such as Cu/W interphase boundaries and W/W grain boundaries.