Cladding Methods Research Articles

Enhancing high-temperature wear resistance of cladded Inconel 718 through hybrid of directed energy deposition with ultrasonic nano-crystal surface modification

We present an innovative method for achieving highly durable and finely controllable internal microstructures within cladded 718 layers utilizing a hybrid cladding approach. This process alternates between two methods: laser directed energy deposition in which four layers of Inconel 718 built up using a laser power of 350 W and a scanning speed of 800 mm/min, and ultrasonic nanocrystal surface modification (UNSM), applied to every fourth deposited surface at elevated temperatures of 300 and 600 °C, with a frequency of 20 kHz and an interval of 0.05 mm, respectively. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) are used to analyze the effect of grain refinement and concentrated dislocation distribution induced by the hybrid cladding. Through the employment of high temperature UNSM treatment between the cladded Inconel 718 layers, profound grain refinement and dislocation enhancement occur, significantly bolstering the wear resistance of the intermediate layer under high temperature conditions. We conducted thorough analyses, employing finite element analysis and experiments, to investigate the diverse temperature conditions of UNSM treatment and their impact on increasing the affected depth of UNSM treatment. Furthermore, we closely examined the changes in microstructure and mechanical properties within the remelted and UNSM-treated zone of the internal layers. Our study confirms that the high temperature hybrid cladding process, operating below 600 °C, resulted in a 27 % reduction in overall material wear-loss compared to conventional cladding methods. Notably, even in high temperature wear tests ranging from 200 to 800 °C, the proposed method significantly mitigated wear amounts in each case, indicating its potential to enhance the mechanical integrity of various components operating under elevated temperature conditions.

A variable diameter spiral path planning strategy for large eccentricity variable curvature rotating parts with focus on thickness and performance control in cladding

When laser cladding rotating parts that have large eccentricity and variable curvature, first-order discontinuities in the cladding path and fluctuations in the real-time scanning speed are common problems. These issues cause significant inhomogeneities in the cladding thickness and localized excessive material accumulation. This not only leads to unstable mechanical properties of the cladding layer but also results in a significant waste of cladding materials during subsequent precision machining. In response, this paper introduces a cladding method that employs a variable diameter constant linear velocity spiral path and establishes models for dynamic vector and angle conversion, constant linear velocity optimization, and cladding path data conversion. This approach enables consistent control over the real-time scanning speed and defocus distance during laser cladding of parts with large eccentricity and variable curvature. A comparison of the experimental results from spiral path cladding, variable linear velocity and variable diameter spiral cladding, and constant linear velocity variable diameter spiral cladding revealed that the latter method achieves a more uniform cladding layer thickness, with a maximum deviation of only 0.036 mm. The microstructure primarily consists of cellular structures, demonstrating improved consistency. Samples were taken from three different cladding methods, and hardness tests were performed on the cross-sections of the cladding layers.

Comparison of the microstructure and properties of 19Al–24Cr–19Ti–37Ni–1Y high-entropy alloy fabricated through conventional and ultrahigh-speed laser cladding methods

Compared with conventional laser cladding (CLC), ultrahigh-speed laser cladding (UHSLC) can dramatically increase cladding efficiency. In this study, a new 19Al–24Cr–19Ti–37Ni–1Y eutectic high-entropy alloy coating was prepared through CLC and UHSLC, tested, and characterized. Results showed that the dilution rate of the UHSLC-HEA coating was 20.2 %, which was only half that of the CLC-HEA coating. The UHSLC-HEA coating had a lamellar spacing of 100 nm and an average grain size of 2.2 μm, which was only one-third of the average grain size of the CLC-HEA coating. The microhardness of the UHSLC-HEA coating was 210 HV0.5 higher than that of the CLC-HEA coating. The coefficient of friction and wear rate of the UHSLC-HEA coating had reduced by 43 % and 34 %, respectively, relative to those of the CLC-HEA coating. UHSLC enhances the wear resistance of coatings by reducing dilution rate, refining grain size, and promoting the formation of a second phase.

Rapid preparation of nanocrystalline high-entropy alloy coating with extremely low dilution rate and excellent corrosion resistance via ultra-high-speed laser cladding

Ultra-high-speed laser cladding (UHSLC) not only offers an efficient solution to the limitations of conventional laser cladding but also aligns with the contemporary objectives of material conservation and efficiency enhancement in metal protective coatings. This study investigates the fabrication of CrFeCoNiMo0.2 high-entropy alloy (HEA) coatings using UHSLC and traditional laser cladding (TLC) methods. Key aspects such as macroscopic forming quality, element distribution, dilution rate, grain morphology, hardness, and electrochemical corrosion properties of both UHSLC and TLC coatings are thoroughly examined. Notably, UHSLC-produced coatings, with their significantly reduced thickness ranging from 100 to 300 μm, demonstrate an impressively low substrate dilution rate compared to the 2–3 mm thickness of TLC coatings. The rapid solidification inherent in UHSLC leads to smaller grain sizes in the coating, resulting in enhanced hardness. Moreover, the UHSLC coating exhibits superior corrosion resistance, characterized by a lower maintaining-passivity current density in 1 mol/L H2SO4 and a higher self-corrosion potential relative to TLC coatings. This work presents a novel approach, employing high-efficiency and low-cost laser-cladding technology, to minimize dilution in the matrix and improve the coating properties of HEAs.

Усунення ливарного браку деталей методами мікроплазмового наплавлення

Усунення ливарного браку деталей методами мікроплазмового наплавлення

Scaling laws for the additive manufacturing of the AISI 316 L deposited by laser surface cladding and direct metal deposition methods

This study presents a comparative analysis of the shape and microstructure of individual tracks formed from AISI 316 L stainless steel using laser surface cladding (LSC) and direct metal deposition (DMD) methods. The research aims to identify the relationship between laser radiation parameters (laser spot size, radiation power, scanning speed) and geometric characteristics of created tracks. The result shows that the change in the geometric characteristics of single tracks (depth, width, and height) can be related to two dimensionless parameters: normalized enthalpy H and Peclet number Pe. Based on the experimental data summary, the limiting values of the conditions for realizing keyhole melting (H > 2, Pe < 10) and heat conduction (H < 2, Pe > 10) were determined.

High-efficiency fabrication of Inconel 625 coating for AISI 1045 carbon steel through laser cladding with hot wire: Microstructure and wear resistance

Laser cladding has been widely used to prolong the service life of components by preparing wear-resistant coatings on the surfaces of engineering parts. However, the efficient fabrication of large-area coatings with desired properties remains a challenge for traditional laser cladding methods. In this paper, based on laser cladding with hot wire, the Inconel 625 single track with desirable geometrical characteristics was first prepared under the stable liquid-bridge transfer mode of the filler wire. Then, defect-free multi-track Inconel 625 cladding layers were fabricated on the surface of the AISI 1045 steel shaft and plate with a higher wire deposition rate of 1.72 kg/h and lower deposited line energy of 61.3 J/mm. The microstructure, phases formed, microhardness, and wear resistance of the cladding layer were investigated. The results indicated that the microstructure of the Inconel 625 cladding layer was mainly composed of a large number of columnar dendrites, with an average grain size of 12 μm. The growth direction of the columnar dendrites in the single deposited track was perpendicular to the substrate surface while it was between 50° to 90° in the multi-track cladding layer. γ-Ni (FCC) was the main phase presented in the Inconel 625 cladding layer. The dilution ratio of Fe was 6 % because of the lower line energy applied in the deposition process. The average microhardness of the Inconel 625 cladding layer was 262 HV1, which was 27.8 % higher than that of the substrate. Inconel 625 cladding layer experienced adhesive wear with a lower friction coefficient of 0.572 and a minimal wear loss of 0.442 × 10−3 g. Similar to microhardness, Inconel 625 cladding layer exhibited better wear resistance than the AISI 1045 steel substrate at room temperature under dry sliding conditions.

Influences of the cladding method and overlapping rate on the multi-channel overlapping of composite coatings

Composite surface coatings had poor flatness rates and unmelted gaps in the multi-channel overlapping process. The mathematical prediction models of the overlapping rate, flatness rate, and defect rate were established based on the single factor test to reveal the coupling effect of the overlapping rate on the flatness and defect rates (pore area and unmelted gaps) of coatings under different cladding methods. The large flatness rate and small defect rate were optimized to obtain the optimal overlapping rate under different cladding methods based on grey correlation analysis. Finally, the cladding efficiency was used as an index to determine the optimal cladding method. The model had a certain prediction ability. The flatness rate first increased and then decreased with the increased overlapping rate; the defect rate first decreased and then increases with the increased overlapping rate. The optimal overlapping rate was obtained with 30 % circular sequence overlapping to derive maximum surface flatness and the minimum defect rate. The coating could reach 13.986 mm2, and the cladding efficiency could reach 69.930 mm3/s at this time. Results showed that the multi-index grey correlation analysis had certain feasibility for the optimization of laser cladding process parameters. The work provides references for the multi-objective optimization of the surface properties of laser cladding composites as well as a theoretical basis for the comprehensive comparison of coating performance under different cladding methods and overlapping rates.

Microstructure and Properties of Nickel-Based Gradient Coatings Prepared Using Cold Spraying Combined with Laser Cladding Methods

A cold spray-laser cladding composite gradient coating (CLGC) was successfully formed on a Cu substrate. In comparison with traditional laser cladding gradient coatings (LGC), cold spraying the pre-set Ni-Cu alloy's intermediate transition layer not only mitigates the negative impacts due to the high reflectivity of the copper substrate but also helps to minimize the difference in the coefficients of thermal expansion (CTE) between the substrate and coating. This reduces the overall crack sensitivity and improves the cladding quality of the coating. Besides this, the uniform distribution of hard phases in CLGC, such as Ni11Si12 and Mo5Si3, greatly increases its microhardness compared to the Cu substrate, thus resulting in the value of 478.8 HV0.5 being approximately 8 times that of the Cu substrate. The friction coefficient of CLGC is lowered compared to both the Cu substrate and LGC with respective values of 0.28, 0.54, and 0.43, and its wear rate is only one-third of the Cu substrate's. These results suggest CLGC has excellent anti-wear properties. In addition, the wear mechanism was determined from the microscopic morphology and element distribution and was found to be oxidative and abrasive. This approach combines cold spraying and laser cladding to form a nickel-based gradient coating on a Cu substrate without cracks, holes, or other faults, thus improving the wear resistance of the Cu substrate and improving its usability.

An overview of recent trends and challenges of post treatments on magnesium alloys

The rise in manufacturing and operating expenses in the oil and gas sector, especially in the impact of corrosive environments and wear influences, has triggered technologists to concentrate more on effectual surface modification strategies on the machines and equipment being produced in recent days. Magnesium alloys are attractive metals in the lightweight materials group due to their lower density and higher specific strength. Even though the corrosion and tribological performance of magnesium alloys are not satisfactory and surface modification techniques are adopted with various coating methods such as electroplating, thermal spray, arc spray, and plasma spray methods to overcome these limitations. Recently, post-spraying technologies have been extensively used to enhance the whole performance of coatings, particularly those developed through the electro deposition, plasma spraying technique, high-velocity oxygen fuel spraying, PVD coatings, electro plating, laser cladding, anodizing, metal cladding, and friction stir processing methods. The development of lightweight components is one of the primary concerns of the automobile, aerospace, and electronics industries. Even though most efficient design procedures contribute to lightweight component development, the usage of lightweight materials plays a significant role. The current review investigates the enhancement of various type of coatings by the various types of post treatments. The purpose of this article is to quickly address future developments, the rising use of magnesium alloys with consideration of explosive environments, and post-treatment effects. Thus, it was concluded that the magnesium-based alloys clearly demonstrate a substantial improvement in their performance in terms of mechanical and corrosion resistance, creating a potential for their use in advanced production techniques for the automotive and aerospace industries. In addition, friction stir process was suggested as a novel post treatment method for metals and alloys. This comprehensive review has been motivated by these advantages of all the post-treatments methods.

Excellent thermal shock resistance of NiCrAlY coatings on copper substrate via laser cladding

• NiCrAlY layers were prepared on copper substrate via laser cladding technology. • Metallurgical bonding and excellent thermal shock resistance are obtained. • Lifetime of this NiCrAlY layers is much longer than NiCrAlY by other methods. Coatings are widely used to protect substrates in extreme thermal environments (e.g., arc heaters), and thermal shock resistance is a crucial parameter for the coatings, which requires tight interlayer bonding between coatings and substrates. In this work, NiCrAlY coatings were highly required for the pure copper substrate to restrict the electric arc in arc heaters. To overcome the bonding difficulty of coating on the copper surface, the NiCrAlY coatings were prepared by two laser cladding methods: conventional laser cladding (CLC) and high-speed laser cladding (HSLC). The microstructure, composition, and thermal shock resistance of NiCrAlY cladding layers prepared by both methods were investigated. Benefitting from the high cooling rate and high energy density, the HSLC-layer has better composition uniformity and tighter interlayer bonding than the CLC-layer, achieving a 30%–45% improvement in thermal cycling lifetime. Besides, the NiCrAlY layers prepared on copper substrate by both laser cladding methods exhibit 3–10 times better thermal shock resistance than those NiCrAlY layers prepared by conventional spraying methods. It further confirms the great effects of metallurgical bonding and composition uniformity on the thermal shock resistance of coatings. The NiCrAlY layers fail in the form of internal cracking and interface peeling, and the corresponding failure mechanism is discussed.

The in-situ re-melting post-treatment on properties of atmosphere plasma-sprayed FeCoCrMoCBY amorphous alloy coating

PurposeThis paper aims to verify weather atmospheric plasma spray (APS) in situ remelting posttreatment is effective for densifying the porous FeCoCrMoCBY amorphous alloy (FAA) coating and improving the antiabrasion and anticorrosion performances or not.Design/methodology/approachAPS was used to deposit and in situ densify FAA coating on the 40Cr substrate. Scanning electron microscope, X-ray diffractometer, energy dispersive spectroscopy, neutral salt spray, hardness and wear behavior test were used to evaluate the densifying effects.FindingsAPS remelting technology can effectively improve the hardness of the coating by reducing the porosity. After remelting at 30 kW power, the hardness of the coating increased by about 260 HV0.2 and the porosity decreased to 2.78%. The amorphous content of the coating is 93.9%, which is about 3.5% lower than original powders. The electrochemical impedance spectrum and neutral salt spray test results show that APS remelting can reduce the corrosion rate by about 62.7%.Originality/valueAPS remelting method is firstly proposed in this work to replace laser remelting or laser cladding methods. APS remelting method can effectively improve the corrosion and abrasion resistance of the FAA coating by increasing the densification with much low recrystallization, which is big progress for application of FAA coatings.

An overview of recent advancement in grade cladded surface using overlay techniques and various materials

In this review paper, previous studies on effect of cladding on surface of welding using overlay was discussed. The Research papers up to 2021 related with various cladding methods, effect on mechanical properties and overlay methods were discussed. Also, paper discussed the effect on tribological behavior. This paper reported the various metal and its alloy, recent development in advanced materials for cladding in various high temperature applications. The merits, demerits, limitations and future development and possible area of research in welding cladding methods were discussed.

Microstructures, Corrosion Resistance and Wear Resistance of High-Entropy Alloys Coatings with Various Compositions Prepared by Laser Cladding: A Review

Nowadays, high-entropy alloys (HEAs) have become a hot research topic in the field of coating materials. However, HEAs have a large wide range of compositional systems, and the differences in their composition inevitably lead to the significant variations in the matching process parameters of laser cladding and post-treatment methods, which in turn give the coatings a broad range of microstructures and protective properties. Therefore, it is crucial to review and summarize the research progresses on laser cladding HEA coatings to provide a reference for obtaining high-performance HEA coatings and further expand the application of HEA coatings. This work describes the working mechanism of laser cladding and illustrates the advantages and drawbacks of laser cladding in detail. The effects of the addition of alloying elements, process parameters and post-treatment techniques on the microstructures and properties of the coatings are thoroughly reviewed and analyzed. In addition, the correlations between the chemical compositions of HEAs, process parameters of laser cladding, post-treatment techniques and the microstructure and protective properties of the coatings are investigated and summarized. On this basis, the future development direction of HEA coatings is outlined.

The Comparative Analysis of the Fe–Cr–C–Ti–Al Coatings Synthesized by Laser, Arc and Hybrid Cladding Methods

The Comparative Analysis of the Fe–Cr–C–Ti–Al Coatings Synthesized by Laser, Arc and Hybrid Cladding Methods

Mechanical Properties of White Metal on SCM440 Alloy Steel by Laser Cladding Treatment

The bearing is a machine element that plays an important role in rotating the shaft of a machine while supporting its weight and load. Numerous bearings have been developed to improve durability and life, depending on the functions and operating conditions in which they are desired. White metal is one of method to improve durability that is soft and bonded to the inner surface of the bearing to protect the bearing shaft. Currently, the centrifugal casting process is used as a white metal lamination method, but it involves problems such as long processing times, high defect rates and harmful health effects. In this paper, a laser cladding treatment is applied to bond powdered white metal to SCM440 alloy steel, which is used as bearing material in terms of replacing the risks of a centrifugal process. In order to understand whether laser cladding is a suitable process, this paper compares the mechanical properties of white metal produced on SCM440 alloy steel by centrifugal casting and the laser cladding process. The laser power, powder feed rate and laser head speed factors are varied to understand the mechanical properties and measure the hardness using micro Vickers and conduct field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and friction testing to understand the mechanical properties and surface characteristics. Based on the results, the hardness values of the cladding (white metal) layer ranged between 24 and 26 HV in both the centrifugal casting and laser cladding methods. However, the hardness of the white metal produced by laser cladding at about a depth of 0.1 mm rose rapidly in the cladding process, forming a heat-affected zone (HAZ) with an average hardness value of 200 HV at a laser power of 1.1 kW, 325 HV at 1.3 kW and 430 HV at 1.5 kW. The surface friction testing results revealed no significant differences in the friction coefficient between the centrifugal casting and laser cladding methods, which allows the assumption that the processing method does not significantly influence the friction coefficient.

Influence of laser remelting on organization, mechanical properties and corrosion resistance of Fe-based amorphous composite coating

Laser cladding and laser remelting methods were adopted to prepare Fe-based amorphous coating on H13 steel surface. And the organization and properties after laser cladding and laser remelting were compared. The results show that, the amorphous content of the coating decreased after laser remelting, and arc crystalline band was formed in the coating, at the same time, after laser remelting, the elements were in ladder-shaped distribution in the amorphous region and crystalline region. After laser remelting, defects on the coating like cracks or pores decreased obviously, but there was a transcrystalline crack extending to the matrix through the crystalline region in the remelting laser beam . The hardness of the crystalline region after remelting increased by about 200 HV compared with that in the amorphous region, and the overall corrosion resistance of the remelting layer was higher than the cladding layer. • Amorphous coating without obvious defects on the upper surface was prepared. • The laser-remelted coating hardness was increased for existence of large amount of hardening phases in the crystalline region • The overall corrosion resistance of the laser-remelted coating was improved due to the elimination of cracks and other defects.

Advanced welding and cladding methods using auxiliary cold and hot wires

The paper presents the features of various fusion welding and cladding methods using auxiliary cold and hot wires in order to increase productivity and improve the quality of welded joints and deposited layers. The introduction lists the various methods of welding that use an additional wire is heated as well as cold. The section “Theoretical and experimental results” presents a method for calculating heat input into a base metal using a heated filler wire and shows the dependence of heat input on its relative amount. The effect of different amounts of filler wire on the shape and size of the welds is shown. A comparative assessment of the effectiveness of using various schemes for introducing an additional heated filler wire into the weld pool was made. The article discusses the use of standard equipment for welding with an additional inverter source for heating filler wire. The influence of automation of the TIG process with cold and hot wire on the lateral shrinkage of 0.8%C-15%Cr-5%Ni-2%Cu-1%Ti-0.7%Si heat resistant steel was studied. The optimal heating conditions were determined to reduce the concentration of Fe in the third layer of deposited metal in the nodes operating in the underwater production of hydrocarbons. The findings present the results achieved in the course of this study, as well as its theoretical and practical significance. The general patterns of the use of arc-free heating of the wire, including in the extended overhang of the electrode, are revealed. Methods have been developed for calculating the heating modes of additional filler wires of various diameters and chemical compositions.

Microstructures and mechanical properties of FeCoCrNi high entropy alloy/WC reinforcing particles composite coatings prepared by laser cladding and plasma cladding

FeCoCrNi HEA coatings with 20% mass fraction of WC reinforcing particles were prepared by two different cladding methods, laser cladding (LC) and plasma cladding (PC). The microstructure of HEA matrix and WC particles of LC and PC coatings were discussed respectively. For HEA matrix, dendritic morphology was observed in both coatings. For WC particles, a few granular (Cr,W)2C carbides around WC particles in LC coatings, and a large number of crystal and fishbone Fe3W3C carbides around WC particles in PC coatings. Mechanical properties as hardness and wear resistance of the two kinds of coatings were also investigated. The interstitial solution strengthening effect of C element is stronger in PC coating, and the hardness of HEA matrix in LC coatings is twice that of in PC coating, which shows a strong retention force on WC particles. The friction coefficient of LC coating is lower and stable, with the volume wear rate of 0.7 × 10−5 mm−3/N·m, showing high wear resistance. PC coatings have poor wear resistance due to decarbonization and oxidation of WC particles and reduction of retention force of HEA matrix, with the volume wear rate of 8.29 × 10−5 mm−3/N·m. The wear mechanism of both coatings were also discussed.

Microstructure investigation of Inconel 625 coating obtained by laser cladding and TIG cladding methods

The purpose of this study was to investigate the microstructure of the Ni base Inconel 625 coatings that were fabricated on the Inconel 738 substrate with two processes of laser cladding and TIG cladding. For this purpose, single-pass samples were precipitated to obtain optimal parameters. In the laser cladding method, laser power, laser scanning rate and powder feed rate were considered as variables, and current and its type were considered as variables for the TIG method. Based on the results, using the parameters of optimum single-pass samples that were free of porosity, crack and had minor geometric dilution, coatings were applied in both methods with 50% overlap. In order to microstructural, elemental and phasic characterization, field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used. Based on the results, the microstructure of coatings from surface to interface of coating/substrate consists of coaxial, columnar and cellular structure dendrites, respectively, and the laser coating has a finer microstructure due to the higher cooling rate. In addition, the austenite, carbide and Laves phases were observed in both coatings.