Achieving ultra hard refractory multi-principal element alloys via mechanical alloying

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

卷:763

Article

Smeltzer, Joshua A.¹  Marvel, Christopher J.¹  Hornbuckle, B. Chad²  Roberts, Anthony J.²  Marsico, Joseph M.²  Giri, Anit K.²  Darling, Kristopher A.²  Rickman, Jeffrey M.¹  Chan, Helen M.¹  Harmer, Martin P.¹ 

[1] Lehigh Univ, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA

[2] US Army Combat Capabil Dev Command Army Res Lab, Weap & Mat Res Directorate, Ceram & Transparent Mat Branch, Aberdeen Proving Ground, MD 21005 USA

关键词: Multi-principal element alloys;    Mechanical alloying;    Thermal stability;    Hardness;    Scanning transmission electron microscopy;   

DOI  :  10.1016/j.msea.2019.138140

来源: Elsevier

【 摘 要 】

Mechanical alloying was employed to produce a nanostructured Mo25Nb25Ta25W25 multi-principal element alloy (MPEA) with enhanced mechanical properties. Overall, a 400% increase in hardness was achieved, as compared to similar cast alloys, via mechanical alloying and optimized long-term annealing treatments. Furthermore, advanced characterization, including aberration-corrected scanning transmission electron microscopy, was conducted to elucidate processing-structure-property relationships in which it was determined that, although the introduction of impurities via mechanical alloying is common and thought to be deleterious, impurities can lead to an impressive enhancement of mechanical properties. More specifically, in this study, Fe and N impurities resulted in the formation of nanoscale, ceramic secondary phases. The observed strengthening was attributed, at least in part, to the ceramic impurity phases. Overall, we suggest that a deliberate doping strategy may be employed in the future to tailor MPEA chemistry and thereby achieve superior mechanical properties.

【 授权许可】

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