Investigation of Elastic Deformation Mechanism in As-Cast and Annealed Eutectic and Hypoeutectic Zr–Cu–Al Metallic Glasses by Multiscale Strain Analysis

Metals

Hiroshi Suzuki⁵  Rui Yamada¹  Shinki Tsubaki⁴  Muneyuki Imafuku⁴  Shigeo Sato³  Tetsu Watanuki²  Akihiko Machida²  Junji Saida¹ 

[1] Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan;Quantum Beam Science Center, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148, Japan;Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan;Faculty of Engineering, Tokyo City University, Setagaya, Tokyo 158-8857, Japan;;Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195, Japan

关键词: hypoeutectic Zr–Cu–Al bulk metallic glass;    structural relaxation;    X-ray scattering;    pair distribution function;    elastic modulus;   

DOI  :  10.3390/met6010012

来源: mdpi

【 摘 要 】

Elastic deformation behaviors of as-cast and annealed eutectic and hypoeutectic Zr–Cu–Al bulk metallic glasses (BMG) were investigated on a basis of different strain-scales, determined by X-ray scattering and the strain gauge. The microscopic strains determined by Direct-space method and Reciprocal-space method were compared with the macroscopic strain measured by the strain gauge, and the difference in the deformation mechanism between eutectic and hypoeutectic Zr–Cu–Al BMGs was investigated by their correlation. The eutectic Zr₅₀Cu₄₀Al₁₀ BMG obtains more homogeneous microstructure by free-volume annihilation after annealing, improving a resistance to deformation but degrading ductility because of a decrease in the volume fraction of weakly-bonded regions with relatively high mobility. On the other hand, the as-cast hypoeutectic Zr₆₀Cu₃₀Al₁₀ BMG originally has homogeneous microstructure but loses its structural and elastic homogeneities because of nanocluster formation after annealing. Such structural changes by annealing might develop unique mechanical properties showing no degradations of ductility and toughness for the structural-relaxed hypoeutectic Zr₆₀Cu₃₀Al₁₀ BMGs.

【 授权许可】

CC BY   
© 2016 by the authors; licensee MDPI, Basel, Switzerland.