Anomalous thermal expansion in the deep super-cooled liquid region of a ZrCuAlAg bulk metallic glass

作者：Hu, Q.; Wang, J. M.; Yan, Y. H.; Luo, F. F.; Guo, S.; Liu, J.; Chen, S. S.; Huang, B.; Lu, D. P.; Zou, J. Z.^*; Zeng, X. R.^*

来源：Materials Research Letters, 2018, 6(2): 121-129.

DOI：10.1080/21663831.2017.1408713

• Bulk metallic glasses
• super-cooled liquid
• viscous flow
• nano-crystals
• grain boundary

Bulk metallic glasses (BMGs), like other glasses, soften in the super-cooled liquid region (SCLR). Here in this work, surprisingly, a large expansion is reported occurring in the deep SCLR of a Zr47Cu37Al8Ag8 BMG. Nano-crystals (NCs) are found precipitated during the anomalous expansion of Zr47Cu37Al8Ag8, but also in the SCLR of Zr43Cu41Al8Ag8 that exhibits a conventional softening. It is found that there is a steep composition and density change at the NCs/amorphous matrix transition region in the former alloy, and this transition region exerts a thermal stress of about 0.15 MPa to the surrounding super-cooled liquid (SCL) and drives the soft SCL to expand severely.
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• 出版日期2018
• 单位江西省科学院; 西北工业大学; 深圳大学; 凝固技术国家重点实验室