In-situ TiB2 and Fe2Ti intermetallic assisted hard coatings by Fe-Ti-B based hardfacing electrodes

• Published in: Journal of alloys and compounds 2022-04, Vol.900, p.163478, Article 163478
• Main Authors: Kocaman, Engin, Kılınç, Bülent, Şen, Şaduman, Şen, Uğur
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Arc welding; Coated electrodes; Coefficient of friction; Composition; Corrosion; Corrosion effects; Corrosion potential; Corrosion resistance; Corrosive wear; Electrode polarization; Fe2Ti; Ferroalloys; Hard surfacing; Hardfacing; Hardness; Hardness tests; Intermetallic phases; Low carbon steels; Microstructure; Nanoindentation; Protective coatings; Solidification; Substrates; Surface properties; TiB2; Titanium; Titanium diboride; Wear; Wear resistance; Wear tests
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.163478

•Coating on Fe(18−x)TixB2 (x = 3–5) based hardfacing steel surface with different titanium content.•The effect of titanium content on the microstructure of Fe-Ti-B based coatings.•Determination of the mechanical properties of the hard surface alloy layer depending on the titanium content. [Display omitted] The aim of this study was to form Fe2Ti and TiB2 phases on the steel surface in-situ using ferroalloy starting materials and to investigate the changes in the surface properties such as microstructural, hardness, wear and corrosion behavior. To this end, Fe(18−X)TiXB2 (x = 3–5) based hardfacing electrodes were produced and coated on AISI 1010 steel substrate using electric arc welding method. The development of the substrate-coating interface, solidification behavior and microstructural conditions of the samples were examined using a variety of characterization methods. In the coating microstructures, intermetallic phases such as TiB2 and Fe2Ti, α-Fe + Fe2Ti eutectic structure and trace amounts of non-equilibrium phases were detected. It has been understood that these phases formed in the microstructure have important effects on the hardness, wear and corrosion resistance of the coating. In the hardness test performed by nanoindentation method, very high hardnesses such as 3254 (± 26) HV in TiB2 phase and 1130.1 (± 13) HV in Fe2Ti phase were measured. As a result of the ball on disc reciprocal wear test performed against Al2O3 ball at different loads, it has been observed that titanium has an effect on the friction coefficient, and the wear resistance increases with the increasing amount of titanium in the electrode cover composition. In addition, according to the potentiodynamic polarization test results carried out in 3.5% NaCl solution, it has been determined that the corrosion potential increased with increasing titanium in the electrode cover composition, there was no linear change detected in the current density.