Ni-based Alloy Composite Coatings Research Articles

The effect of ultrasonic power on high temperature wear and corrosion resistance for Ni based alloy composite coatings

TiO2-reinforced Ni-W co-depositions are successfully produced by ultrasonic-assisted pulse electrodeposition. The effect of ultrasonic powers and concentration of TiO2 on the surface morphology, surface roughness, nano-mechanical, anti-corrosion, high-temperature wear, and friction behavior of the Ni-W co-depositions were systematically investigated. The experimental results indicate that (1) there is an optimal incorporating amount (about 20 g L−1) of TiO2 in the plating bath and ultrasonic power (50 W) for achieving the highest high-temperature wear, corrosion resistance and excellent nanomechanical properties (hardness of ∼8 GPa and elastic modulus of ∼209 GPa), maximum TiO2 incorporation rate (24.4 wt% TiO2); (2) the composite coating refined the microstructure and reduced crystallite size of the coatings, and obtained dense microstructure. TiO2-reinforced Ni-W co-deposition produced by optimal conditions open up new avenues in alternative to hard chromium and is expected to be widely applied in defense industry, automobile and electronic systems.

The Effect of Ultrasonic Power on High Temperature Wear and Corrosion Resistance for Ni Based Alloy Composite Coatings

The Effect of Ultrasonic Power on High Temperature Wear and Corrosion Resistance for Ni Based Alloy Composite Coatings

Microstructure and Wear Behavior of NbC-Reinforced Ni-Based Alloy Composite Coatings by Laser Cladding

This work aims to evaluate the influence of laser power and reinforcement feeding rate on the microstructure, hardness, and wear behavior of NbC-reinforced Hastelloy C276TM alloy composite coatings. From a dual feeding system, one-step metal-matrix composite coatings were deposited with 10, 30, and 50% mass feeding of NbC powder with laser powers of 1.5 and 3.0 kW. Coatings deposited with 1.5 kW and 30% NbC showed some degree of porosity due to a combination of NbC feeding rate and melting pool temperature. Laser power and NbC feeding rate altered the melting efficiency and substrate burn-in shape, remarkably influencing the dilution. The composite microstructure was comprised of Ni-γ (FCC) dendrites with interdendritic network carbide which, in turn, ranged from lamellar-like M6C to blocky-like conjugated MC-M23C6 carbide. Primary petaloid-like MC [Nb] carbide was formed from a 30% reinforcement rate on, whilst a considerable number of unmelted particles was observed for 50%. The higher the reinforcement feeding rate, the higher the carbide fraction and better wear performance of low heat-input specimens. Synthesis with high heat-input sheds a light on the deleterious effect of the dilution and is not an option to enhance the wear performance.

Characteristics Study on in-situ NbC Particles Reinforced Ni-based Alloy Composite Coating by Laser Cladding

The in-situ synthesized NbC particles reinforced Ni-based alloy composite coating was successfully fabricated by laser cladding a precursor mixture with a mass percentage of 80%Ni-based alloy powder (Nb10 powder) and 20% Cr3C2 powder on Q235 steel substrate. Another composite coating was also produced by laser cladding using 100% Ni-based alloy powder as cladding material for comparison. X-ray diffraction (XRD), scanning electron microscopy(SEM), energy spectrum analysis(EDS), microhardness measurement and wear resistance test were performed on the cladding coating. The results show that Ni-based alloy composite cladding coatings are homogeneous and free from cracks, the cladding coating and the substrate exhibit excellent metallurgical bonding. The main phases of the composite coating were (Fe,Ni) solid solution, NbC and Cr23C6 reinforced phases. Abundant NbC particles can be uniformly formed via in-situ reaction between niobium and Cr3C2 in the molten pool during the laser cladding process, and they are commonly precipitated in three kinds of morphologies: granular, quadrilateral and petaloid shape. However, the comparative coating was only composed of (Fe,Ni) solid solution, without the formation of any carbides. The microhardness and wear resistance of composite coating of NbC particle reinforced composite cladding coating were improved significantly, the results indicate that the existence of NbC particles plays a crucial role in enhancing the performance of the cladding coating.

Wear Behaviors of TiN/WS2 + hBN/NiCrBSi Self-Lubricating Composite Coatings on TC4 Alloy by Laser Cladding

TiN and WS2 + hBN reinforced Ni-based alloy self-lubricating composite coatings were fabricated on TC4 alloy by laser cladding using TiN, NiCrBSi, WS2, and hBN powder mixtures. Energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffractometry (XRD), and optical microscopy (OM) were adopted to investigate the microstructure. The wear behaviors of the self-lubricating composite coatings were evaluated under large contact load in room temperature, dry-sliding wear-test conditions. Results indicated that the phases of the coatings mainly include γ-Ni, TiN, TiNi, TiW, WS2, and TiS mixtures. The average microhardness of the composite coating is 2.3–2.7 times that of the TC4 matrix. Laser cladding TiN/WS2 + hBN/NiCrBSi self-lubricating composite coatings revealed a higher wear resistance and lower friction coefficient than those of the TC4 alloy substrate. The friction coefficient (COF) of the coatings was oscillating around approximately 0.3458 due to the addition of self-lubricant WS2 + hBN and hard reinforcement TiN. The wear behaviors testing showed that the wear resistance of the as-received TC4 was significantly improved by a laser cladding TiN/WS2 + hBN/NiCrBSi self-lubricating composite coating.

Microstructure and Properties of NiFeCrBSi/WC Composite Coatings Fabricated by Vacuum Cladding

Abstract—In this study, WC-reinforced Ni-based alloy composite coatings were fabricated on the surface of ASTM 1045 steel by vacuum cladding. The microstructure, hardness, and wear resistance of coatings with different tungsten carbide (WC) content and dissolution mechanisms for WC at different cladding temperatures were studied. The bonding phase was mainly composed of austenite (Ni2.9Cr0.7Fe0.36, FeNi), and the reinforced phases consisted of WC, carbides (Cr7C3, (Cr,Fe)7C3), borides, and silicides. The dissolution of WC became severe with increasing cladding temperature, and the reaction products mainly included rounded block-shaped WC particles, lath-shaped rich tungsten carbide, and fine granular carbides. The Ni-based coating with 30% WC sintering at 1225°C performed better wear resistance, six times greater than that of matrix steel.

Strategy of incorporating Ni-based braze alloy in cold sprayed Inconel 718 coating

Ni-based superalloy (Inconel 718) and Ni-based braze alloy (MAR-M 002) composite coatings were deposited on Inconel 718 substrates via a high-pressure cold spray process. The effects of post heat treatment on microstructural evolution and chemical diffusion of the composite coatings were systematically investigated. The microstructures of the powders and composite coatings were investigated using scanning electron microscopy, electron backscatter diffraction, energy-dispersive X-ray spectroscopy and nanoindentation. After cold spray deposition, it was found that MAR-M 002 particles were uniformly distributed within the as-sprayed composite coatings. During the heat treatment process, it was noted that the diffusion of chemical species occurred across the Inconel 718 and MAR-M 002 particulate interfaces with the width of the diffusion zone being around 10 μm. The enhanced chemical diffusion between Inconel 718 and MAR-M 002 particles could effectively heal out the splat boundaries and reduce coating porosity, which was proved with the microstructure analysis. The effect of chemical diffusion on interparticle bonding strength was investigated through tensile testing. The heat-treated Inconel 718/MAR-M 002 composite coating had a tensile strength of about 810 MPa that was about 17% higher compared to the heat-treated pure Inconel 718 coating. From the SEM observations, the fractured surface of the heat-treated IN718/MAR-M 002 composite specimen was characterized by the presence of more dimples, which indicated a higher fraction of metallurgically bonded interparticle boundaries. These results demonstrated that the proposed methodology for the formation of Inconel 718/MAR-M 002 composite deposits was beneficial for improving the interparticle bonding strength in the deposits.

Tribological properties and wear prediction model of TiC particles reinforced Ni-base alloy composite coatings

TiC particles reinforced Ni-based alloy composite coatings were prepared on 7005 aluminum alloy by plasma spray. The effects of load, speed and temperature on the tribological behavior and mechanisms of the composite coatings under dry friction were researched. The wear prediction model of the composite coatings was established based on the least square support vector machine (LS-SVM). The results show that the composite coatings exhibit smaller friction coefficients and wear losses than the Ni-based alloy coatings under different friction conditions. The predicting time of the LS-SVM model is only 12.93% of that of the BP-ANN model, and the predicting accuracies on friction coefficients and wear losses of the former are increased by 58.74% and 41.87% compared with the latter. The LS-SVM model can effectively predict the tribological behavior of the TiCP/Ni-base alloy composite coatings under dry friction.

Microstructure and wear properties of Al 2 O 3 -CeO 2 /Ni-base alloy composite coatings on aluminum alloys by plasma spray

Abstract Al2O3 and CeO2 particles reinforced Ni-base alloy composite coatings were prepared on aluminum alloy 7005 by plasma spray. The microstructure, microhardness, fracture toughness, critical bonding force and the wear behavior and mechanisms of the composite coatings were investigated. It is found that CeO2 particles can refine crystal grains, reduce porosity and unmelted Al2O3 particles in the composite coatings. The microhardness, fracture toughness, critical bonding force and wear resistance of the composite coatings are enhanced due to synergistic strengthening effects of Al2O3 and CeO2 particles. The friction coefficients and wear losses increase as loads increase. At the loads of 3–6 N, the composite coatings experience local plastic deformation and micro-cutting wear. At the loads in the range of 9–12 N, the calculated maximum contact stress and maximum tensile stress on friction surfaces increase leading to plastic deformation induced working hardening. The wear mechanisms change into micro-brittle fracture wear and slight oxidative wear.

Tribological properties of laser cladding TiB2 particles reinforced Ni-base alloy composite coatings on aluminum alloy

To improve the wear resistance of aluminum alloy frictional parts, TiB2 particles reinforced Ni-base alloy composite coatings were prepared on aluminum alloy 7005 by laser cladding. The microstructure and tribological properties of the composite coatings were investigated. The results show that the composite coating contains the phases of NiAl, Ni3Al, Al3Ni2, TiB2, TiB, TiC, CrB, and Cr23C6. Its microhardness is HV0.5 855.8, which is 15.4 % higher than that of the Ni-base alloy coating and is 6.7 times as high as that of the aluminum alloy. The friction coefficients of the composite coatings are reduced by 6.8 %–21.6 % and 13.2 %–32.4 % compared with those of the Ni-base alloy coatings and the aluminum alloys, while the wear losses are 27.4 %–43.2 % less than those of the Ni-base alloy coatings and are only 16.5 %–32.7 % of those of the aluminum alloys at different loads. At the light loads ranging from 3 to 6 N, the calculated maximum contact stress is smaller than the elastic limit contact stress. The wear mechanism of the composite coatings is micro-cutting wear, but changes into multi-plastic deformation wear at 9 N due to the higher calculated maximum contact stress than the elastic limit contact stress. As the loads increase to 12 N, the calculated flash temperature rises to 332.1 °C. The composite coating experiences multi-plastic deformation wear, micro-brittle fracture wear, and oxidative wear.

Microstructure and Tribological Properties of WC-CeO2/Ni- base Alloy Composite Coatings

The Ni-base alloy composite coatings synergistically reinforced by WC and CeO2 particles were prepared on the surface of 7005 aluminum alloy by the plasma spray technique. The microstructures and the tribological properties of the composite coatings were researched. The results show that with the addition of CeO2 particles, the microstructure of the composite coating is refined; meanwhile, the WC reinforcing particles change from round to irregular polygon and their decarburization are alleviated. The friction coefficients and the wear losses of the composite coatings are lower than those of the WC/Ni-base alloy composite coatings and the Ni-base alloy coatings at different PV values. When the PV values are smaller than 3.36 N·m/s, the maximum contact stress of the composite coating is lower than its elastic limit contact stress, the wear mechanisms of which are mainly micro-cutting wear and fatigue wear. As the PV values are bigger than 3.36 N·m/s, the maximum contact stress exceeds the elastic limit contact stress of the composite coating and the contact temperature sharply increases to 648 °C, obvious plastic deformation and desquamation traces appear on the worn surface and the wear mechanisms turn into multi-plastic deformation wear, abrasive wear and adhesive wear accompanied with oxidative wear.

Dissolution of Tungsten Carbide in Remanufacturing Coating by Plasma Spray Welding

The tungsten carbide reinforced Ni-based alloy composite coatings are prepared on the surface of 45 steel by plasma spray welding in back feeding method. The dissolution of Ni-based WC composite coatings was investigated. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy diffraction spectrum (EDS) were used to examine the microstructure and composition of the coatings. The results show that the WC particles are well-distributed in the matrix. The WC particles have a good wettability with Ni-based substrate. In the spraying process, the WC particles have been dissolved obviously, and the diffusion occurs between the WC particles and Ni-based substrate. The surface of the coatings has a microstructure consisting of WC, W2C, Fe7C3, Cr7C3 and γ- (Fe, Ni) solid solution. The hardness increases from the matrix to the surface of coatings and is up to 2311 HV.

Tribological properties of nanostructured Al2O3-40%TiO2 multiphase ceramic particles reinforced Ni-based alloy composite coatings

The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and tribological properties of the composite coatings were researched. The results show that the composite coatings mainly consist of γ-Ni, α-Al2O3, γ-Al2O3 and rutile-TiO2 etc, and exhibit lower friction coefficients and wear losses than the Ni-based alloy coatings at different loads and speeds. The composite coating bears low contact stress at 3 N and its wear mechanism is micro-cutting wear. As loads increase to 6–12 N, the contact stress is higher than the elastic limit stress of worn surface, and the wear mechanisms change into multi-plastic deformation wear, micro-brittle fracture wear and abrasive wear. With the increase of speeds, the contact temperature of worn surface increases. The composite coating experiences multi-plastic deformation wear, fatigue wear and adhesive wear.

Tribological properties of TiC particles reinforced Ni-based alloy composite coatings

The TiC particles reinforced Ni-based alloy composite coatings were prepared by plasma spray. The microstructure and tribological properties of the composite coatings were investigated. The results show that the composite coatings are mainly composed of γ-Ni, CrB, Cr7C3 and TiC. A transition layer of 9.4 μm in thickness forms at the interface, indicating the metallurgy bond between the composite coating and the substrate. When the content of TiC particles is 30% in volume fraction, both of the friction coefficient and wear rate of the composite coatings reach the lowest values. The friction coefficient is 0.33 which is reduced by 30% compared with the pure Ni-based alloy coating; the wear rate is 0.3×10−3 mm3/m which is about 1/3 that of latter. Under the load of 6-10 N, the composite coatings are in a slight wear stage and their wear mechanisms are mainly adhesive wear. Under the high load of 12 N, the composite coatings suffer from severe wear, and the wear mechanisms change into the desquamation of the hard phases and the delamination of the transferred layer.

Tribological behavior and mechanisms of graphite/CaF2/TiC/Ni-base alloy composite coatings

In order to reduce the friction coefficients and improve the wear resistance of mechanical parts, which work in the severe friction and wear conditions at heavy loads, the graphite/CaF2/TiC/Ni-base alloy composite coatings were prepared by plasma spray and their tribological behavior and mechanisms were investigated. The results show that the friction coefficients of the composite coatings are in the range of 0.22–0.288, which are reduced by 25.9% to 53% compared with those of the pure Ni-base alloy coatings, and the wear rates of the former are 18.6%–70.1% less than those of the latter. When wear against GCr15 steel balls, a transferred layer mainly composed of ferric oxides, graphite and CaF2 may gradually develop on the worn surface of the composite coatings, which made the friction and wear between GCr15 steel ball and the composite coatings change into that between the former and the transferred layer. So the friction coefficients and the wear rates of the composite coatings are greatly reduced because of the solid lubrication effect of the transferred layer. The main wear mechanism of the composite coatings is delamination of the transferred layer in friction process.

Tribological properties of Ni-base alloy composite coating modified by both graphite and TiC particles

In order to reduce the friction coefficient of Ni-base alloy coating and further improve its wear resistance, Ni-base alloy composite coatings modified by both graphite and TiC particles were prepared by plasma spray technology on the surface of 45 carbon steel. The results show that friction coefficient of the composite coating is 47.45% lower than that of the Ni-base alloy coating, and the wear mass loss is reduced by 59.1%. Slip lines and severe adhesive plastic deformation are observed on the worn surface of the Ni-base alloy coating, indicating that the wear mechanisms of the Ni-base alloy coating are multi-plastic deformation wear and adhesive wear. A soft transferred layer abundant in graphite and ferric oxide is developed on the worn surface of the composite coating, which reduces the friction coefficient and wear loss in a great deal. The main wear mechanism of the composite coating is fatigue delamination of the transferred layer.

Microstructure and properties of laser clad TiC+NiCrBSi+rare earth composite coatings

TiC particle reinforced Ni-based alloy composite coatings were clad to AISI 4140 chromium molybdenum alloy steel substrate using a laser. The microstructure and tribological behavior of coatings were studied experimentally by means of scanning electron microscopy, transmission electron microscopy and wear tests. Partial solution of TiC particles occurs in the laser melting pool during the heating stage. Twins and dislocations were observed at the interface of TiC particles and the matrix. The wear resistance was found to correlate with the load and amount of the TiC particles present in the clad layer. By adding La 2O 3, the hardness of clad coatings was significantly increased, and the wear resistance of clad coatings was enhanced.

Laser clad ZrO 2Y 2O 3 ceramic/Ni-base alloy composite coatings

A laser cladding technique was used to produce ZrO 2Y 2O 3 ceramic/ Ni-base alloy composite coatings on stainless steel 4Cr13. The microstructure and hardness of the composite coatings are analyzed by XRD, SEM, EPMA, TEM and microhardness testing techniques. A stratification is observed in the laser clad zone. The upper region of the clad is a pure ZrO 2 ceramic layer, and the lower region is an excellent transition layer of Ni-base alloy. The ZrO 2 ceramic layer exhibits equiaxed grains and columnar structure of t' phase and a tiny network structure of m phase along the t' boundaries. The transition layer of Ni-base alloy shows the multi-phase structure of primary γ-Ni dendrites and dendritic eutectic, at interdendritic regions, of (Fe, Cr) 23C 6 carbide plus γ-Ni phase.