Cold Gas Dynamic Spray Research Articles

Study of coatings of the Ni–Ti–(SiC, WC, B4C) system applied to the surface of titanium alloy plates using cold gas dynamic spraying and laser processing

The technology of applying composite intermetallic coatings of the Ni–Ti system reinforced with carbides based on powders (SiC, WC, B4C) on the surface of titanium alloy plates with the sequential use of the CGDN method and laser processing is considered. The technological parameters of the laser-thermal processing, ensuring the production of composite coatings of the Ni–Ti–(SiC, WC, B4C) system of high hardness, are determined.

Cold gas dynamic additive spraying of functionally graded Cu matrix composites reinforced by high entropy oxides

Cold gas dynamic spraying was attempted as a new technique to additively fabricate functionally graded Cu-matrix composites reinforced by BaFe12O19 and its corresponding BaFe6(AlCrTiGaCo)6O19, BaFe2(AlCrTiGaCo)10O19 and BaFe6(AlCrSnGaCo)6O19 high entropy oxides (HEOs) particles. The BaFe12O19 and HEOs reinforcement particles, prepared by solid-phase sintering and ball milling, exhibited a single BaFe12O19-type structure and homogenous microstructure. Cu-matrix composites with a gradient lamellar microstructure were successfully deposited, in which the coarse Cu layers formed at the bottom of the samples gradually transformed to a more refined microstructure along the deposition direction. The reinforcement particles were incorporated between and within the Cu lamellas. The samples exhibited a gradient microhardness pattern that increased from bottom to the surface of the samples along the deposition direction. Cu-20% BaFe6(AlCrSnGaCo)6O19 composite exhibited the highest microhardness value of 195 HV at its top surface which decreased to about 142 HV at its bottom. Second phase strengthening is considered as the main strengthening mechanism. The as-sprayed Cu alloy exhibited an electrical conductivity of 86%IACS, and this value was about 68.7, 78.8, 64.3 and 69.3%IACS for the composites samples reinforced by 20wt.% BaFe12O19, BaFe6(AlCrSnGaCo)6O19, BaFe6(AlCrTiGaCo)6O19, and BaFe2(AlCrTiGaCo)10O19 respectively. Finally, cold gas dynamic spraying is introduced as an effective additive manufacturing method to fabricate free-standing functionally graded Cu-matrix composites reinforced by different oxide particles.

Development of technology for obtaining nanostructured composite coating of Kh20N80–Cr–TiC

The paper presents results of a comprehensive study on the development of technology for the production of composite nanostructured functional coatings based on the Kh20N80 – chromium – TiC system using the supersonic cold gas dynamic spraying method. Composite coating powders are obtained by chromium plating of a matrix powder made of alloy Kh20N80 followed by the application of a reinforcing coating of TiC nanoparticles. The resulting coating has a high level of microhardness, modulus of elasticity and resistance to wear. A distinctive feature of the resulting coating is its reliable operation without destruction for a long time (more than 4800 hours).

ИССЛЕДОВАНИЕ ИЗНОСОСТОЙКОСТИ ГИЛЬЗ ЦИЛИНДРОВ, ВОССТАНОВЛЕННЫХ КЕРАМИЧЕСКИМ ПОКРЫТИЕМ

The results of the study of the workability and wear resistance of the combined coating of the restored cylinder liners obtained by applying a layer of aluminum powder to the cast-iron base by cold gas-dynamic spraying with subsequent treatment by microarc oxidation were presented. (Research purpose) The research purpose is a comparative analysis of the tribotechnical properties of the conjugations "sleeve coated with cold gas-dynamic spraying and treatment with microarc oxidation-counter-sample 100Cr6" and "sleeve (SH25 in the delivery state)-counter-sample 100Cr6" (reference pairing). (Materials and methods) Conducted a study of the workability of materials of the reference and reconstructed conjugations according to RD 50-662-88 "Guidelines. Methods of experimental evaluation of frictional compatibility of materials of friction conjugations". Comparative bench tests were performed on the wear resistance of the reference and restored conjugates according to GOST 23.224-86 "Ensuring the wear resistance of products. Methods for assessing the wear resistance of restored parts". (Results and discussion) The optimal modes of long-term operation and the limits of the interface operability were determined during the stepwise loading of the reference and restored tribo-couplings. The run-in coefficient and the wear factor of the couplings were calculated. It was found that the restored coupling "sleeve coated with cold gas-dynamic spraying and microarc oxidation treatment-counter-sample 100Cr6" has similar run-in rates with the reference coupling, and its wear resistance exceeds the wear resistance of the reference coupling by more than two times. (Conclusions) High indicators of workability and wear resistance of the restored interface "sleeve coated with cold gas-dynamic spraying and microarc oxidation treatment-counter-sample 100Cr6" in comparison with the reference sleeve (from SCH25 in the state of delivery) provide an increase in its durability and indicate the expediency of using the combined method in the restoration of cylinder liners.

Properties of ceramic coatings in engine cylinder liners restoration using combined technology

In the course of vehicle operation with internal combustion engines, due to various reasons, defects occur on the cylinder mirror, resulting in the need for repair work to eliminate them. For non-cylinder blocks most often requires replacement with a new block, which is economically very costly. The technologies of liner restoration are very diverse and their application depends on the available equipment and material of the liner. The aim of the work is to develop a new combined technology for the restoration of liners and cylinder blocks regardless of the material for their manufacture. As a technology of restoration of the geometry of the mirror of the liner the method of cold gas dynamic spraying with the use of aluminum powder is considered. Subsequent application of the plasma electrolytic oxidation (PEO) technology makes it possible to obtain on the mirror a ceramic coating with thickness of 80-100 microns, which is sufficient for long-term operation of the internal combustion engine. On the basis of GZ-195N liner the technology of cylinder mirror restoration was worked out and the process of plasma electrolytic oxidation (PEO) was carried out. Research has shown that the hardening of the coating occurs to the depth of 100 microns required by the technology. The wear resistance of the coating exceeds the wear resistance of the reference sample, its wear factor is 1.27 times less than that of the reference pair. The possibility of using the technology of aluminum coating by cold spray on any metal makes the combined technology of cylinder liner repair applicable to achieve the desired result - to restore the performance of the cylinder block or liner and increase their wear resistance. The obtained positive results require the development of industrial technology of combined coating and experimental testing on a running engine.

Repair of radiators of the engine cooling system of agricultural machinery: use of cold gas-dynamic spraying

Repair of radiators of the engine cooling system of agricultural machinery: use of cold gas-dynamic spraying

Fabrication of a Ti-based 3D porous transport layer for PEMWEs using ShockWave-induced spraying and cold spray

Cost-effective production of green hydrogen is contingent upon reducing the capital cost of Polymer Electrolyte Membrane Water Electrolysers (PEMWE). Currently, 17 to 25 % of the production cost of a PEMWE stack depends on components related to the Porous Transport Layer (PTL). PTLs are usually made of compressed and sintered titanium powders/fibers to provide them with structural and chemical integrity with carefully controlled interconnected porosity. Herein, we report on the preparation of Ti-based PTLs produced by Shock-Wave Induced Spray (SWIS) and Cold Gas Dynamic Spray (CGDS), two deposition processes that does not require any subsequent heat treatment. This report investigates the effect of using porogens to control the porosity of the Ti-based PTLs. Two porogens, Cu and Al, were used to investigate the effect of porogen density on the deposition efficiency and porosity of the resulting coatings. The Al porogen allowed for the production of Ti-based PTLs coatings with ca. 60 % porosity, which is a very desirable feature for producing PTLs with high gas permeability.

Enhancing the Microhardness of Coatings Produced by Cold Gas Dynamic Spraying through Multi-Reinforcement with Aluminum Powders Containing Fullerenes and Aluminum Nitride

Coatings with high hardness were successfully obtained using low-pressure cold spray (LPCS) technology from nanocrystalline powders based on the aluminum alloy AlMg6, which were multi-reinforced with 0.3 wt.% fullerenes and 10–50 wt.% AlN. The powders were synthesized through a two-stage high-energy ball milling process, resulting in a complex mechanical mixture consisting of agglomerates and micro-sized ceramic particles of AlN. The agglomerates comprise particles of the nanocomposite material AlMg6/C60 with embedded and surface-located, micro-sized ceramic particles of AlN. Scanning electron microscopy and EDS analyses demonstrated a uniform distribution of reinforcing particles throughout the coating volume. An X-ray diffraction (XRD) analysis of the coatings revealed a change in the predominant orientation of matrix alloy grains to a more chaotic state during deformation over the course of cold gas dynamic spraying. A quantitative determination of AlN content in the coating was achieved through the processing of XRD data using the reference intensity ratio (RIR) method. It was found that the proportion of transferred ceramic particles from the multi-reinforced powder to the coating did not exceed ~65%. Experimental evidence indicated that LPCS processing of mono-reinforced nanocrystalline powder composite AlMg6/C60 practically did not lead to the formation of a coating on the substrate and was limited to a monolayer with a thickness of ~10 µm. The microhardness of the monolayer coating obtained from the deposition of AlMg6/C60 powder was 181 ± 12 HV. Additionally, the introduction of 10 to 50 wt.% AlN into the powder mixture contributed to the enhancement of growth efficiency and an increase in coating microhardness by ~1.4–1.7 times. The obtained results demonstrate that the utilization of agglomerated multi-reinforced powders for cold gas dynamic spraying can be an effective strategy for producing coatings and bulk materials based on aluminum and its alloys with high microhardness.

Cold spray coating: A review of material systems and future perspectives

Spraying solid powders onto a substrate at high velocity with a de Laval nozzle characterizes cold spray, also known as a cold gas dynamic spray (CS). Particles will stick to a surface if the impact velocity is high enough to create a plastic deformation. Metals, ceramics, composites, and polymers are just some materials that may be deposited utilizing CS, opening up a world of interesting possibilities for specialized harvesting applications. CS has some technological advantages compared to thermal spray due to using kinetic energy for deposition. There has been a proliferation of material combinations that can be sprayed utilizing cold spray technology due to the emergence of new material systems with superior properties in disciplines as disparate as internal combustion engines and biotechnology. The need to provide a concise summary of the state of the art increases as the amount of research into a topic grows in line with the breadth of its potential applications. This overview will discuss the various material systems studied for potentially revolutionary uses. Polymer is considered in two contexts: as a substrate and a layer, allowing us to discuss metal incorporation. CS has shown promise in depositing nanostructured materials, unlike many traditional consolidation processes, without significantly altering their microstructure. Relevant material systems, which may include nanostructured powders, are also considered. It examines microstructural bonding techniques for those relatively new material systems and discusses their potential future uses. Examples of suitable materials include ceramics, polymers, MMCs, and nanostructured powders. More study is required, particularly to quantify the relationship between process parameters and the effective behaviour of the targeted material systems.

Development of technology for obtaining functional coatings from Kh15Yu5 steel powders

The paper presents the results of research on the development of technology for the application of functional coatings with high values of adhesion strength, microhardness and wear resistance using the method of supersonic cold gas dynamic spraying. Oxidized powder from X15Yu5 steel was used as a starting material for obtaining such coatings.

Recovery technology by combiningthe rods elektroiskro-hand processing and cold gas dynamic spraying of powder

The results of studies mikrometrazhnyh repair fund crank engine JAMZ-238, JAMZ-236 and Raba-MAN. We describe a new technology diesel engines of recovery of rods with an oblique slot-ism by combining the methods of electrical discharge machines and cold n-zodinamicheskogo spray powders. According to the results of experimental studies identifi ed the physical and mechanical properties and corrosion resistance of fretting in the recovery of rods used coating

Wear Mechanisms of Cold-Sprayed Stellite-6 During Reciprocated Dry Sliding Under Different Sliding Speeds

Cobalt–chromium alloys are often employed in those environments that require reliable wear and friction properties. Cold Gas Dynamic Spray offers the opportunity to obtain good quality deposits of Stellite-6, that can be successfully used in harsh environments, where good surface performance, in terms of wear resistance, is required. It is also well-known that Stellite-6 is subjected to several physical changes at the interface during dry sliding, that are often related to the loading conditions. As a consequence, wear behavior of this alloy can undergo some variations that linear models are not able to capture, since micro-structural modifications occur during operation. To better understand the wear mechanisms of cold-sprayed Stellite-6 coatings together with the occurring physical phenomena, a systematic experimental study was performed, in fact, to date, no such in-depth tribological studies have been performed. Tests were conducted under combinations of two sliding speeds (0.1 and 0.5 m/s) and four contact pressure in the range of 2-5 MPa. In low-speed tests, abrasive wear is evident, where detachment and pull-out phenomena mainly affect the worn surface of coatings. On the other hand, subsurface cracking was observed in high-speed tests, as well as evidence of plastic deformation on the wear surface. These results suggest that observed wear mechanisms are more likely a consequence of adhesive wear. Unique to this study, the cross-sectional nano-indentation tests showed how the stiffness of the coating, near to wear interface, increases significantly in the case of the lowest value of sliding speed (i.e., v = 0.1 m/s), whereas tends to decrease at high speeds, i.e., v = 0.5 m/s, as a consequence of the formation of subsurface cracks into the coating.

Sustainable development in cold gas dynamic spray coating process for biomedical applications: challenges and future perspective review

Sustainable development in cold gas dynamic spray coating process for biomedical applications: challenges and future perspective review

Development of technology for obtaining nanostructured composite powders by high-speed mechanosynthesis

The results of the development of technology for obtaining nanostructured composite powders in two ways – surface reinforcement and cladding are presented. The possibility of manufacturing functional coatings based on the obtained powders by the method of supersonic cold gas-dynamic spraying is shown. The characteristics of the resulting coatings (adhesive strength, microhardness, wear resistance, low porosity) were studied. The real prospect of using the created functional protective coatings for precision engineering is shown.

Calculation and investigation of the phase composition of a composite intermetallic layer synthesized on the surface of VT6 titanium alloy from Cu–SiC and Al–SiC powders

The physical and chemical foundations of the technology of cold gas-dynamic spraying of coatings on titanium for two types of charge are considered, in one of which chemically inactive copper is used as a ductile metal in combination with abrasive silicon carbide powder, in the other – chemically active aluminum in combined with silicon carbide. A thermodynamic modeling technique has been developed to select the composition of the coating charge and predict the change in its phase composition at high temperature.

Cold Spray Aids Development of Decentralized Energy Harvesters

Abstract Moisture-electric energy transformation (MEET) technology is being developed to further expand the utilization of environmental energy sources like thermal power, wind power, hydropower, and solar energy. The goal of the MEET technology is to extract power from environmental moisture with as few conversion processes as possible to satisfy the ever-growing demand for new and more portable energy sources The use of cold spray to produce MEET devices results in a greener process. While the suitability of polyether ether ketone as a MEET material was proven and the deposition of PEEK using cold gas dynamic spray (CGDS) was achieved, additional work is needed to fully characterize the manufacturing of PEEK-based MEET devices via CGDS.

An Attempt to Understand Stainless 316 Powders for Cold-Spray Deposition

Cold gas dynamic spray (CS) is a unique technique for depositing material using high-strain-rate solid-state deformation. A major challenge for this technique is its dependence on the powder’s properties, and another is the lack of standards for assessing them between lots and manufacturers. The motivation of this research was to understand the variability in powder atomization techniques for stainless steel powders and their subsequent properties for their corresponding impacts on CS. A drastic difference (~30%) was observed in the deposition efficiencies (DEs) of unaltered, spherical and similar sized stainless steel (316) powders produced using centrifugal (C.A) and traditional gas atomization (G.A) techniques. The study highlights more the differences on a precursor level. Using recent advancements in large scale statistical measurements, such as laser diffraction shape analysis and µCT scanning; and traditional methods, such as EBSD and nanoindentation, an attempt was made to understand the powder’s properties. Insights on powder size and shape were documented. Significant differences were observed between C.A and G.A powders in terms of grain size, fraction of high-angle grain boundaries (HAGBs) and nanohardness. The outcomes of this study should be helpful for understanding the commercialization of the cold-spray process for bulk manufacturing of powder precursors.

A Study of the Neutron Absorbing Properties of Al + B4C and Al + B Coatings Formed by Cold Gas-Dynamic Spraying

For the first time, the efficiency of thermal neutron absorption by composite coatings deposited by cold gas-dynamic spraying from mechanically activated mixtures of Al + B4C and Al + B powders on the surface of stainless steel samples has been compared with a reference standard. The comparison with the standard, which was boron steel plates, showed that the resulting coatings are somewhat inferior in terms of neutron absorption efficiency. To estimate the required thickness of the coatings, an approach based on the processing of the experimental data obtained is proposed that, in particular, takes into account the dependence of the absorption cross section on the distance traveled by the neutron flux. As well, the analysis has shownthat the existing undulation (periodic inconstancy of the thickness) of the coating has virtually no effect on its protective properties (namely, on its neutron absorption coefficient).

A Study of the Neutron Absorbing Properties of Al + B4C and Al + B Coatings Formed by Cold Gas-Dynamic Spraying

A Study of the Neutron Absorbing Properties of Al + B4C and Al + B Coatings Formed by Cold Gas-Dynamic Spraying

SUBSTANTIATION OF THE CHOICE OF COATING MATERIAL WHEN RESTORING PARTS OF AGRICULTURAL MACHINERY BY COLD GAS-DYNAMIC SPRAYING

Based on the method of cold gas-dynamic spraying, technologies are being created to solve problems of energy and resource saving in various industries and non-traditional and effective methods of production, repair, restoration, anti-corrosion protection, obtaining electrical and heat-conductive, anti-friction and other coatings of functional units, and as well as elements of a wide variety of machinery and equipment. The main feature of cold gas-dynamic spraying is the absence of high temperatures during the formation of metal coatings, therefore, the absence of oxidation of particle and base materials, non-equilibrium crystallization processes, and high internal stresses in the workpieces. Coatings created in this way are a metal matrix with ceramic particles embedded in it. They are characterized by high strength, good performance properties and can be applied in any thickness. One of the important characteristics of coatings is the adhesion strength. Before spraying on any part, it is necessary to find out which coating material will give the best strength characteristics between the two materials. Therefore, before spraying, it is important to study the specifics of the formation of a durable coating for a given part, as well as to compare the strength characteristics of the cold gas-dynamic spraying method with other methods for restoring parts. In this paper, an analysis of various coating materials used in the restoration of parts by the method of cold gas-dynamic spraying is carried out. The strengths and weaknesses of various coating technologies are determined, as well as recommendations for choosing a material when restoring parts by cold gas-dynamic spraying.