No abstract

In the present work, abrasive and erosive wear of wear-resistant composite coatings with a complex structure and different phase compositions deposited on titanium surfaces was studied. The coatings were obtained by electrospark deposition (ESD) using two types of hard-alloy compositions: WC–TiB2–B4C–Co–Ni–Cr–Si–B and TiB2–TiAl reinforced with dispersed nanoparticles of ZrO2 and NbC. The influence of the ESD process parameters on the roughness, thickness, composition, structure and coefficient of friction of the coated surfaces was investigated, and their role in protecting the titanium surfaces from wear was clarified. Dense coatings with the presence of newly formed wear-resistant phases and crystalline-amorphous structures were obtained, with roughness, thickness and microhardness that can be varied by the ESD modes in the range Ra = 2.5 ÷ 4.5 µm, δ = 8 ÷ 30 µm and HV 8.5 ÷ 14.0 GPa. The new coatings were found to reduce the abrasive and erosive wear of the coated surfaces by up to four times. The influence of the geometric characteristics, composition and structure of coatings on the wear intensity and wear resistance of coatings was studied.

A B S T R A C T (10 N, 20 N, 30 N, 40 N)

According to most researchers, improving the tribological characteristics of titanium alloys at this stage is most appropriate through surface modification tribotechnologies. In the present work, the qualitative characteristics of coatings of tungsten-free hard alloy materials materials based on TiC, TiN TiCN TiB2, applied on the most popular titanium alloy Ti6Al4V by electrospark deposition with low pulse energy are investigated. The influence of the electrode materials, the process parameters, the characteristics of the coatings and the roughness parameters on their wear and abrasion resistance has been studied. It was found that the use of coatings from the studied electrodes shows an increase in abrasion resistance by 1.5 -up to 3 times compared to that of the substrate and the electrode materials and process parameters were determined, in which maximum wear resistance was obtained.

This paper examines the topography and roughness of coatings of hard alloyed materials deposited by electrospark deposition (ESD) on titanium and nickel alloys with different initial roughness. The influence of the electrode materials and the energy parameters of the ESD process on the roughness parameters Ra, Rt, Rq, Rz, Rmax, on the depth of waviness Wt, the asymmetry Rsk, the excess Rku, on the depth of core roughness Rk and the depth of the reduced picks roughness Rpk was established. The conditions for ESD are indicated, under which the traces of the previous treatment are erased and the characteristics of the initial substrate surface are improved. The numerical values of the roughness parameters for electrospark coatings from five types of hard alloys and one type of TiB2 based electrode with nanosized additives have been established.