Effects of planetary ball milling on AlCoCrFeNi high entropy alloys prepared by Spark Plasma Sintering: Experiments and molecular dynamics study

JOURNAL OF ALLOYS AND COMPOUNDS

卷:820

Article

Fourmont, A.¹  Le Gallet, S.¹  Politano, O.¹  Desgranges, C.²  Baras, F.¹ 

[1] Univ Bourgogne Franche Comte, CNRS, UMR 6303, ICB, 9 Ave Alain Savary,BP 47870, F-21078 Dijon, France

[2] Safran Tech, Mat & Proc Dept, Rue Jeunes Bois, F-78114 Magny Les Hameaux, France

关键词: Spark Plasma Sintering;    High energy ball milling;    High entropy alloys;    Molecular dynamics;    CALPHAD;    Mechanical activation;   

DOI  :  10.1016/j.jallcom.2019.153448

来源: Elsevier

【 摘 要 】

The elaboration of High Entropy Alloys (HEA) was investigated by means of powder metallurgy. We studied the combination of mechanical activation and reactive sintering in the case of AlCoCrFeNi. Elemental metallic powders were first processed by planetary ball milling over a long duration (28 h). The ratio K between the rotating speed of the sun wheel and the relative rotating speed of the grinding vials was set at 0.2 and 1 corresponding to medium energy milling. Given the particular hardness of chromium as compared to other elements, the effect of Cr powder size was investigated and optimized. In addition to experimental characterizations of milled powders, Molecular Dynamics simulations were carried out in order to assess the formation of solid solutions. The activated powders were then consolidated by Spark Plasma Sintering at 1000 degrees C and 1100 degrees C. A nanostructured lamellar microstructure exhibiting the coexistence of the FCC and BCC phases was synthesized by this solid-state route. The sintered materials exhibited hardness of up to 670 HV. Our final results (i.e., after optimization of the milling and sintering parameters) suggest that mechanical activation combined with reactive sintering is an efficient route to elaborate dense HEA materials. (C) 2019 Elsevier B.V. All rights reserved.

【 授权许可】

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