A large-scale fabrication of flower-like submicrometer-sized tungsten whiskers via metal catalysis

Tungsten powder mixed with an appropriate amount of nickel and iron powders is used as raw material to fabricate large-scale tungsten whisker-like structure. The morphology, microstructure and composition of the whisker-like tungsten are observed and tested by scanning electron microscope and FESEM, transmission electron microscopy, X-ray spectroscopy, and X-ray diffraction, respectively. The main component of the tungsten whisker-like structure is tungsten, which has the axial growth along the <100 > direction with large aspect ratio and possesses flower-like structure. Large-scale submicrometer-sized whisker-like tungsten was fabricated via vapor phase deposition approach with the aid of metal catalysts at 800°C by holding for 6 h in the appropriate atmosphere. The growth procedure of flower-like tungsten whisker is probably based on the vapor-liquid-solid mechanism at beginning of the formation of tungsten nuclei, then vapor-solid mechanism is dominant.