Understanding the influence of high velocity thermal spray techniques on the properties of different WC-based coatings

For decades, coatings have been used all over the world because of its applications versatility in industry for machinery and tools preservation, surfaces protection and corrosion prevention. The main reason for coating materials is the improvement of material functional performance by increasing its resistance to extremely aggressive conditions. Hard metals are a mixture of metal and ceramic materials, where the metallic matrix is ductile enough to act as a binder between ceramic particles. These composites combine the hardness and resistance of a carbide phase, i.e WC, TiC, SiC... with the tenacity and plasticity of a metallic binder (mainly Co, Ni, Cr). This makes possible to obtain materials, which mechanical properties directly dependent on the composition, shape and size of the raw materials.

Thus, the aim of this work is to carry out a comprehensive study of the properties of different hard metal coatings (WC-Co, WC-NiFeCrMo, WC-WB-Co-Cr and WC-Co-Cr) obtained by high velocity thermal spray techniques (HVOF & CGS) onto different metallic substrates. This study will try to get a direct correlation between coatings composition and microstructure, and their functional performance by analysing coatings properties like hardness, toughness, wear resistance and/or corrosion behavior.