Characterization of W-Cr Metal Matrix Composite Coatings Reinforced with WC Particles Produced on Low-Carbon Steel Using Laser Processing of Precoat.

Dariusz Bartkowski,Adam Piasecki,Aneta Bartkowska,Jakub Hajkowski,Paweł Popielarski

doi:10.3390/ma13225272

Dariusz Bartkowski, Adam Piasecki + Show 3 more

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https://doi.org/10.3390/ma13225272

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Abstract

The paper presents the study results of laser processing of precoat applied on C30 steel. The precoat consisted of powder mixtures with a binder in the form of water glass. Tungsten powder, chromium, and tungsten carbide (WC) were used to produce the precoat. The laser processing was carried out using a Yb:YAG disc laser with a rated power of 1 kW. Constant producing parameters (power of laser beam, 600 W; laser beam scanning rate, 400 mm/min) were applied. Chemical composition of the precoat was a variable parameter in coating production. A mixture consisting of 50% W and 50% Cr as a metal matrix was prepared. Subsequently, WC particles in weight ratios of 25%, 50%, and 75% were added to matrix. As a result, W–Cr metal matrix composite coatings reinforced with WC particles were formed. This study focused on investigation of microstructure, microhardness, phase, and chemical composition as well as corrosion and wear resistance, of the newly formed W–Cr/WC coatings. An instrumented nanoindentation test was also used in this study. As a result of laser beam action, the newly formed coatings had an interesting microstructure and good properties which were improved in comparison to substrate material. It is anticipated that the resulting coatings, depending on the treatment parameters (e.g., W–Cr/WC powder mixture) used, can be successfully applied to metal forming or foundry tools.

Highlights

In order to characterize the properties of tool materials, the material should be analyzed in terms of its microstructure and a number of physicomechanical properties
The with a matrix of tungsten and chromium (W–Cr) metal matrix composite coatings reinforced with with tungsten carbide (WC) particles were produced on C30 steel substrate
In the case of W–Cr metal matrix composite coatings reinforced with WC particles, the high microhardness of was no lower than 500 HV0.05

Summary

Introduction

In order to characterize the properties of tool materials, the material should be analyzed in terms of its microstructure and a number of physicomechanical properties. Special attention should be paid to the material core, which must be characterized by both high hardness and high ductility, and to the condition and properties of the material’s surface layer. Metalworking tools, i.e., tools intended for use in such technologies as machining, founding, or, above all, plastic working, are exposed to intense wear due to friction and very often to dynamic loads, which may cause their cracking. The surface layer of the material should be refined with appropriate chemical elements to reduce tool wear. By extending the life of the tools, both the cost of their regeneration and the time needed for their replacement are reduced.

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