Reduction of shear localization through structural rejuvenation in Zr-Cu-Al bulk metallic glass

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:765

Article

Meng, F.¹  Tsuchiya, K.²  Kramer, M. J.³  Ott, R. T.³ 

[1] Sun Yat Sen Univ, Sino French Inst Nucl Engn & Technol, Zhuhai 519082, Guangdong, Peoples R China

[2] Natl Inst Mat Sci, Int Ctr Young Scientist, Seagen 1-2-1, Tsukuba, Ibaraki 3050047, Japan

[3] US DOE, Div Mat Sci & Engn, Ames Lab, Ames, IA 50010 USA

关键词: Severe plastic deformation;    Structural rejuvenation;    Metallic glass;    Pair distribution function;    Nanoindentation;   

DOI  :  10.1016/j.msea.2019.138304

来源: Elsevier

【 摘 要 】

The effect of high-pressure torsion (HPT) on the structure and mechanical behavior of Zr50Cu40Al10 bulk metallic glass was investigated using calorimetry, density measurement, high-energy X-ray scattering and nanoindentation. Increase in rotation number, and thus plastic deformation, lowers the hardness and elastic modulus, as well as the critical strain rate for suppressing the shear localization. Strain-softening induced by plastic deformation is attributed to the structural rejuvenation. Wide-angle X-ray scattering (WAXS) measurements suggest that HPT deformation reduces and broadens the peaks in the pair distribution function indicative of pronounced structural disordering and enabling structural rejuvenation. Measured excess free volume of 0.8% for samples deformed by HPT with a maximum structural relaxation enthalpy of 29.5 J/g in the sample with 20 and 50 revolutions.

【 授权许可】

Free