Size Effect on Flow Behavior of a Zr55Al10Ni5Cu30 Bulk Metallic Glass in Supercooled Liquid State

作者：Wang X Y^*; Deng L; Tang N; Jin J S

来源：Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science, 2014, 45A(8): 3505-3511.

DOI：10.1007/s11661-014-2299-9

Size effect on the flow behavior of Zr55Al10Ni5Cu30 bulk metallic glass in its supercooled liquid state was investigated by compression tests with specimen diameters varying from 1 to 3 mm. It was found that the smaller the specimen, the higher flow stress exhibits. Strain gradient theory considering friction effect is validated to be suitable to rationalize this size effect. The more geometrical-necessary flow sites needed to be created in smaller specimens, the higher stress it may result in. Considering the efficiency of power dissipation and instability condition, processing maps of different specimens were constructed. With the specimen size decreasing, the processing condition corresponding to low temperature or high strain rate becomes disadvantageous to the thermoplastic forming of Zr55Al10Ni5Cu30, which is closely related to the local stress concentration and strain gradient induced by friction.

• 出版日期2014-7
• 单位华中科技大学