The Structure and Properties of Laser-Cladded Inconel 625/TiC Composite Coatings

Abstract

This article presents production results concerning metal matrix composite-coatings made using the laser-cladding technology. The enhancement of the wear resistance of the material surface is the one of the main goals accompanying the manufacturing of composite coatings. Nickel-based superalloys are used in several industries because they are characterized by a number of desirable properties including high tensile and fatigue strength as well as resistance to high-temperature corrosion in aggressive environments. One of the most interesting materials from the group of superalloys is Inconel 625, used as a matrix material in tests discussed in this article. However, nickel-based superalloys are also characterized by an insufficient wear resistance of the surface, therefore, in relation to the tests discussed in this article, Inconel 625-based composite coatings were reinforced by adding 10%, 20% and 40% of titanium carbide particles. The addition of hard phases, i.e., TiC, WC or SiC particles can have a positive effect on the erosion resistance of cladded specimens. The aim of the experiment was to determine the impact of the titanium carbide content on the structure of the alloy and its resistance to corrosive wear, enabling the extension of the service life of Inconel 625/TiC composite coatings. The investigation included microhardness tests, corrosion resistance analysis, penetrant tests, macrostructure and microstructure analyses and X-ray diffraction (XRD) tests. The TiC particles increased the hardness of the coatings and, in general, had a negative impact on the corrosion resistance of pure Inconel 625 coatings. However, the increased homogeneity of composite coatings translated into the improvement of corrosion resistance.

Laser Cladding of NiCrBSi/WC + W2C Composite Coatings

“…The chemical composition of the nickelbased powder used as the metal matrix is given in Table 1. The chemical composition of the matrix powder was selected so as to ensure good technological properties during laser cladding, especially reduction of surface tension and fluidity of the melt pool in order to ensure good wettability of the carbide particles and thus good bonding of the metal matrix with the carbides [1,[7][8][9][10]18]. The powder was gas atomised in argon atmosphere and the spherical particle size range was mainly 45 ÷ 150 µm (Durum, Willich, Germany).…”

“…In industrial production conditions, the NiCr type coatings are deposited mainly by thermal spraying processes, while the composite coatings with Ni-based matrix reinforced by WC carbides mainly by Plasma Tungsten Arc cladding (PTA) [13][14][15][16][17][18].…”

Structure and Hardness Analysis of Inconel 625 Nickel Superalloy Welded by Tig Method

“…For this reason, in nickel superalloys, grain boundaries are reinforced with carbide precipitates, mainly of the M23C6 type [1][2][3][4][5][6]. Researches on nickel and nickel alloys are currently continued in a wide range [7][8][9][10][11][12][13][14][15][16]. They concern welding technologies, such as: soldering, welding of construction elements operated in high temperature and aggressive environment [10], welding of Ni alloys with non-alloy steels and structural analysis of welded joints, as well as joining bimetal with a layer clad with Ni alloys [12,16], or laser welding of finned tubes with Inconel 625 superalloy [13] and formation of surface layers by thermal spraying and welding [7][8][9][10].…”

“…Researches on nickel and nickel alloys are currently continued in a wide range [7][8][9][10][11][12][13][14][15][16]. They concern welding technologies, such as: soldering, welding of construction elements operated in high temperature and aggressive environment [10], welding of Ni alloys with non-alloy steels and structural analysis of welded joints, as well as joining bimetal with a layer clad with Ni alloys [12,16], or laser welding of finned tubes with Inconel 625 superalloy [13] and formation of surface layers by thermal spraying and welding [7][8][9][10]. However, it seems that the research issues of welded joints of thin sheets of Inconel alloys are presented in the available literature only as a contribution [7][8][9][10][11][12][13][14][15][16].…”

“…They concern welding technologies, such as: soldering, welding of construction elements operated in high temperature and aggressive environment [10], welding of Ni alloys with non-alloy steels and structural analysis of welded joints, as well as joining bimetal with a layer clad with Ni alloys [12,16], or laser welding of finned tubes with Inconel 625 superalloy [13] and formation of surface layers by thermal spraying and welding [7][8][9][10]. However, it seems that the research issues of welded joints of thin sheets of Inconel alloys are presented in the available literature only as a contribution [7][8][9][10][11][12][13][14][15][16]. The main aim of the research was to determine the structure and the hardness of the base material, the heat effected zone and the weld of butt joints of thin sheets with thickness of 1,0 mm made of Inconel 625 nickel superalloy weld by TIG method.…”