Characteristics and Microstructure of Coatings of Ultradisperse TiB2-TiAl Electrodes with Nanosized Additives Deposited on Ti-Gr2 by Non-Contact Electrospark Deposition

The article considers issues related to improving the surface characteristics of titanium Gr2 using one of the lightest, cheapest and ecological methods - electrospark deposition (ESD) with low pulse energy and with ultradisperse electrodes TiB2-TiAl with nanosized additives of NbC and ZrO2. By means of profilometric, metallographic, XRD, SEM and EDS methods, the change in the geometric characteristics, composition, structure, micro- and nanohardness of the coatings as a function of the electrical parameters of the ESD regime has been studied. The results show that the use of TiB2-TiAl electrodes and low pulse energy allows the formation of dense, continuous and uniform coatings, demonstrating a significant reduction in roughness and inherent irregularities and structural defects of electrospark coatings, as well as the synthesis of newly formed wear-resistant phases and amorphous-nanocrystalline structures. The obtained coatings have crystal-line-amorphous structures, with newly formed intermetallic and wear-resistant phases with minimal defects, with roughness, thickness and microhardness, which can be controlled within the ranges Ra =1.8-3.5 µm, δ= 8-20 µm, HV=9-13 GPa, respectively. Energy pulse parameters have been defined to produce of coatings with a predetermined thickness and roughness, maximum increased hardness and with the most favorable characteristics in terms of abrasive and corrosion resistance.