Papers by Keyword: Electron-Beam Cladding

Abstract: Structural and phase states of wear-resistant coatings obtained by cladding of self-fluxing nickel-based powder mixtures (77 % Ni, 15 % Cr, 2 % B, 3 % Si, 3 % Fe and others) using an electron beam injected in the atmosphere were investigated. The fabricated coatings possessed the complex gradient structure combining hard and ductile components. In the structure of coatings iron borides (Fe₂B) surrounded by the ductile matrix represented by Fe, Ni-based γ-solid solution were observed. An increase in the volume fraction of a high strength component in the coating can be reached by additional alloying of the surface by amorphous boron. In this case, microhardness of the coating increases up to 1200 HV.

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.

Abstract: Structure, microhardness and fracture features of coatings produced by atmospheric electron-beam cladding of amorphous boron were investigated. The coatings were produced by cladding of one, two and three layers of powder. Produced coatings thickness is 550, 750 and 900 μm respectively. The peak level of microhardness is 14000…16000 MPa. By the means of XRD analysis it is stated that the main phases of strengthened layers are FeB and Fe₂B borides and eutectic (α-Fe + Fe₂B). The coatings after one layer cladding have non-uniform structure with microvolumes having lack of borides. Three-layered coatings are noted for their high brittleness. The best properties are presented by two-layer coatings.