Influence of Ag and Co additions on glass-forming ability, thermal and mechanical properties of Cu-Zr-Al bulk metallic glasses

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

卷:673

Article

Escher, B.¹  Kuehn, U.¹  Eckert, J.^1,2,4,5  Rentenberger, C.³  Pauly, S.¹ 

[1] IFW Dresden, Inst Complex Mat, POB 27 01 16, D-01171 Dresden, Germany

[2] Tech Univ Dresden, Inst Mat Sci, D-01062 Dresden, Germany

[3] Univ Vienna, Fac Phys, Boltzmanngasse 5, A-1090 Vienna, Austria

[4] Univ Leoben, Austrian Acad Sci OAW, Erich Schmid Inst Mat Sci, Jahnstr 12, A-8700 Leoben, Austria

[5] Univ Leoben, Dept Mat Phys, Jahnstr 12, A-8700 Leoben, Austria

关键词: Amorphous materials;    Metallic glasses;    Mechanical properties;    Calorimetry;    X-ray diffraction;   

DOI  :  10.1016/j.msea.2016.06.081

来源: Elsevier

【 摘 要 】

In this study, the effect different amounts of Ag and Co have on thermal stability, phase formation and mechanical properties of the glass-forming alloys (Cu0.5Zr0.5)(95)-(x).-yAl5AgxCoy (2 <= x <= 5 and 0 <= y <= 2) and CU47.5-yZr47.5Al5COy (0 <= y <= 2) was investigated, respectively. The addition of Ag increases the glass forming ability (GFA) of the alloys by enhancing the stability of the undercooled melt and by simultaneously reducing the stability of the B2 CuZr high-temperature phase. Co instead, has the opposite effect. It leads to an increased thermal stability of the B2 phase, as well as a decreased stability of the under cooled melt and, consequently, lowers the GFA of the alloys. Moreover, a metastable big cube phase precipitates in some alloys stabilized by oxygen, which is introduced during casting. There is a strong interdependence between the phase formation and the tendency of the present alloys to vitrify. This correlation can be captured by the K-parameter (Song et al. 2011 [11) calculated from the respective transformation temperatures. The plastic strain of the present ternary, quaternary and quinary alloys reflects the GFA as well: the higher the tendency to form a glass, the smaller the plastic strain. Once B2 crystals precipitate in the glass, the plasticity is enhanced significantly. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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