Structure and Properties of Coatings Obtained by Electron-Beam Cladding of Ti+C and Ti+B₄C Powder Mixtures on Steel Specimens at Air Atmosphere

Abstract

The surface layer of steel was reinforced by electron-beam cladding at air atmosphere. Two types of powder mixtures were used to receive coatings: (1) titanium and graphite, (2) titanium and boron carbide. The formation of heterogeneous structure was observed in specimens after the electron-beam treatment by the methods of optical microscopy and scanning electron microscopy. The X-ray diffraction analysis was used to analyze the phase composition of the coatings. The wear resistance level of the coatings was estimated by friction test against loosely fixed abrasive particles. It was found that surface alloying of steel with carbon containing components led to the formation of material with an enhanced wear resistance level.

SEM Studies on the Microstructure and Phase Composition Distribution in Cr₃C₂ + TiC Claddings on Low-Carbon Steel

“…Combination of the effect of the electron beam with the introduction of alloying elements enables creation of Febased coatings with hardening phases. A number of coatings on low-carbon steel have been studied up to now including claddings of titanium, carbon and molybdenum [1], iron and graphite [2,3], iron and boron [4], titanium, carbon and boron carbide [5] mixtures; boron [6], boron carbide [7] and tungsten carbide [8,9]; chromium carbides without other compounds and in combination with titanium carbide [10,11]. The thickness of the clad coatings can reach some millimeters depending on the irradiation conditions, so the structural characteristics obtained in local areas or averaged ones are usually used when the structure and phase composition of the coatings are described.…”

The Structure, Microhardness and Wear Resistance of Coatings Obtained through Non-Vacuum Electron Beam Cladding of Chromium and Titanium Carbides on Low Carbon Steel

“…The researches from Novosibirsk technical state university apply powders of pure elements which form hard, wear-and corrosion resistant phases during the heating under electron beam irradiation. They created and investigated a number of coatings on low carbon steel using cladding of boron [1], the mixtures of titanium, carbon and molybdenum [2], iron and carbon [3], iron and boron [4], titanium, carbon and boron carbide [5], Ni-Cr-Si-Fe-B [6], etc. The scientific team from Tomsk uses carbide powders to clad, including chromium carbide separately and in combination with titanium carbide [7], boron carbide [8] and tungsten carbide [9].…”

Cladding of Ni-Cr-Si-B Powder Coatings by an Electron Beam Injected into the Atmosphere

“…In addition to tradition approaches based on the use of diffusion processes, melting methods of thin surface layers and their subsequent rapid solidification were developed. In most cases these technological processes are accompanied by adding refractory compounds to a liquid melt in order to improve physical and mechanical properties of the coatings under formation [1][2][3].…”