A Novel Approach to the Rapid in situ Synthesis of Tungsten Carbide Nanopowder by Plasma Milling and Carbothermal Reduction

作者：Zeng, Meiqin; Pan, Youtao; Liu, Weifeng; Cui, Jie; Lu, Zhongchen^*; Zhu, Min

来源：ADVANCED ENGINEERING MATERIALS, 2023, 25(5): 2200175.

DOI：10.1002/adem.202200175

• plasma milling
• tungsten carbide
• WC-Co hard metal
• WO3-C precursor

This work prepares nanocrystalline tungsten carbide (WC) powder using conventional ball milling or plasma milling (P-milling) to process tungsten trioxide (WO3)-carbon (C) mixtures, with subsequent carbothermal reduction. The aim is to assess the effects of a discharge plasma on the microstructure of these materials. The results indicates that WC powders with particle sizes of less than 100 nm could be fabricated through heating at a relatively low temperature of 1150 degrees C for 1 h under vacuum after P-milling. This process is found to allow a lower processing temperature and provided more complete carburization in comparison with conventional ball milling. P-milling is determined to produce more loosely adhering WO3 nanoparticles and a higher surface area, resulting in more reactive sites and a larger contact area between WO3 nanoparticles and C atoms. This technique simultaneously generates more oxygen vacancies and defects on the surfaces of the WO3 and C, respectively, based on the use of a plasma discharge. It is evident that this new technology permits nanocrystalline WC to be readily obtained from WO3 and C in a reduced time span and at a lower cost and greater efficiency. This technique could also be used to fabricate WC nanopowders on an industrial scale.