HVOF spraying of a new generation of high-energy ball milled TiC-FeCr powders as alternative to conventional cermets and hard chromium

Nowadays, it is estimated that a 3% of the global energy consumption is related to repairing tasks due to wear issues. For many decades, hard chromium and carbide coatings have been accepted as the main option for enhancing hardness and wear resistance of materials. In case of carbide coatings, also hardmetals, this phase is alloyed with a metal matrix, frequently nickel and/or chromium but also cobalt, which brings toughness to the material. In spite of the high properties of these coatings, nowadays, there is a big concern about the toxicity and environmental impact of both materials, hard chromium and carbides. Thus, the aim of this work is to study the opportunities of a new generation of materials, “green carbides”, as an alternative to conventional cermet coatings. For this study, two new materials, prepared by high-energy ball milling (HEBM), with FeCr-based metallic matrix and TiC as carbide phase have been sprayed by HVOF onto different substrates. In this powder, the FeCr matrix improves the corrosion resistance of the material whilst, replacement of carbide phase by TiC leads to obtain a lighter coating. Morphology, microstructure, wear resistance or hardness are some the properties tested in order to optimize the spraying parameters.