Optimizing ductility and fracture of amorphous metal thin films on polyimide using multilayers
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- 作者：Hai T. Tran ; Hesham Mraied ; Sina Izadi…
- 关键词：Al–Mn alloy ; Thin film ; Polymer substrate ; Multilayer ; Fracture toughness ; Finite element simulation
- 刊名：International Journal of Fracture
- 出版年：2017
- 出版时间：April 2017
- 年：2017
- 卷：204
- 期：2
- 页码：129-142
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Characterization and Evaluation of Materials; Classical Mechanics; Civil Engineering; Automotive Engineering; Mechanical Engineering;
- 出版者：Springer Netherlands
- ISSN：1573-2673
- 卷排序：204
文摘
Aluminum–manganese (Al–Mn) thin films with manganese concentration up to 20.5 at.% were deposited on polyimide (PI) substrates. A variety of phases, including supersaturated fcc (5.2 at.% Mn), duplex fcc and amorphous (11.5 at.% Mn), and completely amorphous phase (20.5 at.% Mn) were obtained by adjusting alloying concentration in the film. Tensile deformation and subsequent fracture of strained Al–Mn films on PI were investigated experimentally and by finite element simulations. Compared with crystalline and dual phase counterparts, amorphous thin film exhibits the highest fracture stress and fracture toughness, but limited elongation. Based on the fracture mechanism model, a multilayer scheme was adopted to optimize the ductility and the fracture properties of the amorphous film/PI system. It was found that by sandwiching the amorphous film (20.5 at.% Mn) between two ductile Cu layers, the elongation can be improved by more than ten times, and the interfacial fracture toughness by more than twenty times. This design provides important guidelines to obtain optimized mechanical properties of future flexible electronics devices.