Nanostructured Tungsten Through Cryogenic Attrition

Keywords

Cryomilling; Grain size; Microstructure; Nanocrystalline; Tungsten

Abstract

Nanostructured pure tungsten (W) powders have been fabricated through cryogenic attrition (i.e., cryomilling) in a liquid nitrogen medium for the first time. The microstructure and chemistry of W powders before and after 4 and 12 h of cryomilling were thoroughly examined by gas fusion chemical analysis, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy (TEM). Cryomilling in liquid nitrogen protected the tungsten from oxygen and hydrogen contamination while introducing nitrogen. Results showed that the W grain size decreased with cryomilling time, and reached approximately 5 nm after 12 h of cryomilling. High resolution TEM suggested that nitrogen reacted with W to form tungsten nitride (WN). Additionally, amorphous W was identified in the 12 h cryomilled W powder. Tungsten carbide (WC) contamination from the milling media and minor Fe-Cr-Ni-containing impurities from the stainless steel vessel were also documented. The WC had grain size ranging from 20 nm to 150 nm, and was homogeneously dispersed in W matrix.

Publication Date

5-30-2015

Publication Title

International Journal of Refractory Metals and Hard Materials

Volume

52

Number of Pages

70-77

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.ijrmhm.2015.05.016

Socpus ID

84930638786 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84930638786

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