High (10-3 s-1) densification rates at <0.25 homologous temperature in pressure assisted densification of nanocrystalline MgO: Effects of water absorption and grain size

SCRIPTA MATERIALIA

卷:169

Article

Dewitt, D. M.¹  Kodera, Y.¹  Garay, J. E.¹ 

[1] Univ Calif San Diego, Adv Mat Proc & Synth Lab, Mat Sci & Engn Program, Mech & Aerosp Engn Dept, San Diego, CA 92103 USA

关键词: MgO;    Water absorption;    Spark plasma sintering (SPS);    Current-activated pressure-assisted densification (CAPAD);    Cold sintering;   

DOI  :  10.1016/j.scriptamat.2019.04.020

来源: Elsevier

【 摘 要 】

We measured the real-time densification rates in the current activated pressure assisted densification (CAPAD) of nanocrystalline MgO. The rates of samples densified from powders with grain sizes similar to 40 nm are similar to those measured previously for other nanocrystalline materials while those from 29 nm powder are higher. Exposing the powders to a humid environment increases the densification rates and allows densification at lower temperatures. The densification rate curves of samples with absorbed water display two peaks implying two controlling mechanisms, while the dry samples display one. We attribute lower temperature densification to Mg(OH)(2)-MgO conversion and the higher to diffusion-controlled densification. (C) 2019 Acta Materialia Inc Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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