Influence of Powder Structure on Decarburization and Microstructure of HVOF Sprayed WC-12wt.%Co Coatings

Abstract:

In order to examine the influences of tungsten carbide particle size on decarburization behavior and microstructure of HVOF sprayed WC-Co coating, four kinds of agglomerated WC-12wt.%Co powders were deposited on mild steel substrates by using a high velocity oxy-fuel (HVOF) spray system. The phase compositions and microstructure of the feedstock powders and sprayed coatings were investigated by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM), respectively. The results showed that the decarburization became more serious with the decreasing of tungsten carbide particle size in the starting powder. W phase was detected in the as-sprayed nanocomposite WC-12wt.%Co coating. All the coatings showed very compact microstructure with the hard phases embedded in Co matrix. The microstructure of HVOF sprayed WC-12wt.%Co coatings depended on the feedstock powder structure. The shape of tungsten carbide particles was rounder and the volume fraction of carbide phase decreased in coatings as the tungsten carbide particle size decreased.

• Periodical: Advanced Materials Research (Volumes 834-836)
• Pages: 609-612
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.834-836.609
• Online since: October 2013
• Authors: Ning Ma, Zhen Xiong Cheng, Huan Tao Wu, Fu Xing Ye
• Keywords: HVOF, Process Optimization, Submicron Structure, WC-12wt.%Co

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