J. Mater. Sci. Technol. ›› 2020, Vol. 45: 187-197.DOI: 10.1016/j.jmst.2019.10.021

• Research Article • Previous Articles     Next Articles

Ice-templated porous tungsten and tungsten carbide inspired by natural wood

Yuan Zhanga,b, Guoqi Tana,c, Da Jiaoa, Jian Zhanga, Shaogang Wanga, Feng Liub, Zengqian Liua,c,*(), Longchao Zhuod,**(), Zhefeng Zhanga,c,*(), Sylvain Devillee, Robert O. Ritchief   

  1. a Laboratory of Fatigue and Fracture for Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    b School of Mechanical Engineering, Liaoning Shihua University, Fushun 113001, China
    c School of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China
    d School of Materials Science and Engineering, Xi’an University of Technology, Xi’an, 710048, China
    e Laboratoire De Synthèse Et Fonctionnalisation Des Céramiques, UMR3080 CNRS/Saint-Gobain CREE, Saint-Gobain Research Provence, Cavaillon 84306, France
    f Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA 94720, USA
  • Received:2019-09-14 Accepted:2019-10-18 Published:2020-05-15 Online:2020-05-27
  • Contact: Zengqian Liu,Longchao Zhuo,Zhefeng Zhang

Abstract:

The structures of tungsten and tungsten carbide scaffolds play a key role in determining the properties of their infiltrated composites for multifunctional applications. However, it is challenging to construct and control the architectures by means of self-assembly in W/WC systems because of their large densities. Here we present the development of unidirectionally porous architectures, with high porosities exceeding 65 vol.%, for W and WC scaffolds which in many respects reproduce the design motif of natural wood using a direct ice-templating technique. This was achieved by adjusting the viscosities of suspensions to retard sedimentation during freezing. The processing, structural characteristics and mechanical properties of the resulting scaffolds were investigated with the correlations between them explored. Quantitative relationships were established to describe their strengths based on the mechanics of cellular solids by taking into account both inter- and intra-lamellar pores. The fracture mechanisms were also identified, especially in light of the porosity. This study extends the effectiveness of the ice-templating technique for systems with large densities or particle sizes. It further provides preforms for developing new nature-inspired multifunctional materials, as represented by W/WC-Cu composites.

Key words: Ice-templating, Tungsten, Scaffolds, Fracture mechanisms, Bioinspired materials