Author: Shou-Yi Chang, Bo-Jien Chen, Yu-Ting Hsiao, Ding-Shiang Wang, Tai-Sheng Chen, Ming-Sheng Leu, Hong-Jen Lai
Institute: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan
Materials Science and Chemical Research Laboratories, Industrial Technology Research Institute, Chutung, 31040, Taiwan
The preparation and nanoscopic plastic deformation of hardened quasicrystalline and vanadium multilayer coatings based on Al-Cu-Fe is an important topic in materials science, aiming to improve the mechanical properties of functional materials. These coatings, due to their unique quasicrystalline structure, exhibit outstanding properties such as high rigidity, excellent corrosion resistance and low friction coefficient.
Ductile vanadium layers were interleaved with brittle layers of quasicrystalline aluminum-copper-iron alloy to form multilayer coatings. TEM studies of the nanopillar compression sites revealed that the single-layer amorphous aluminum-copper-iron alloy deposited as a film experienced slight deformation due to shear bands. After annealing at 800 °C, brittle quasicrystalline and intermetallic components were formed, which led to cracks and coating peeling. In contrast, the multilayer structures were successfully strengthened. The nanopillars of the multilayer structure underwent lamellar deformation through dislocation motion, which contributed to their strengthening. The multilayer structures created by the deposition method showed a low flow stress (1.72 GPa), while the annealed structures showed a higher value (2.58 GPa) due to quasicrystalline strengthening, which increased their ductility.
In the process of preparing coatings, special attention is paid to the spraying technology, the choice of heat treatment conditions and composition control, which is critical for the formation of the desired microstructure. Nanoscopic plastic deformation that occurs under mechanical loads requires detailed study, since it affects the durability and performance characteristics of the coatings. Improvement of these processes opens up new prospects for the creation of highly efficient and reliable materials for use in the aerospace, electronics and automotive industries. The study of interactions between layers and deformation mechanisms is key to the development of new material plant strategies.