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•This article for the first time provides a critical review of the AMCs developed by cold spraying.•A summary of composite powder preparation, CS deposition behavior, microstructure, ...and properties has been made.•It reports the relevant research progress on post-treatments of the AMCs for CS additive manufacturing applications.•The challenges and perspectives on the fabrication of advanced AMCs by CS are addressed.
Cold spraying (CS), or cold gas dynamic spray (CGDS), is an emerging solid-state powder deposition process, allowing fast and mass production and restoration of metallic components. CS of metal matrix composites (MMCs) has attracted increasing attention from academia and industry over the last decades, especially in the area of Al matrix composites (AMCs), which have demonstrated a high potential for applications in aerospace, automotive, and electronics industries. This article aims to summarize the recent development of CS-processed AMCs in terms of composite powder preparation, deposition processing, microstructure evolution, mechanical and corrosion properties. Furthermore, this review also reports the relevant research progress with the focus on post-treatments of the AMCs for CS additive manufacturing applications including heat treatment, hot rolling, and friction stir processing. Finally, the challenges and perspectives on the fabrication of advanced AMCs by CS are addressed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cold spraying (CS) is a solid-state coating technique that has been applied as a novel additive manufacturing (AM) method to fabricate freestanding metal components. Recent advances in cold spray ...additive manufacturing (CSAM) technology call for new process implementation to improve manufacturing accuracy and flexibility. In this study, a concept of modular systems is presented to design and implement a new CSAM framework. The current CSAM system is an open framework system composed of different modules. The flow of the proposed CSAM system is explained to understand the physical and functional relationships between the key elements of the entire system. This physical and functional modularity is useful to promote hybrid AM processes. In addition, based on the smart manufacturing concept of Industry 4.0, a novel approach is proposed to bring the perception and the decision-making abilities into the traditional CS system. Here, a 3D profiler is used to measure the morphology of deposited coatings online and to transfer data to the robot controller. The developed algorithm compares the obtained results with a theoretical model to ensure an adaptive adjustment of the robot trajectory. The experimental validation shows that this approach achieves closed-loop control for CSAM with high-precision by optimizing kinematic parameters in real time.
Applications in thermal and kinetic spraying increasingly aim for coating of parts with complex geometries. So far, respective robot programming for the required path during deposition is usually ...adjusted individually in time-consuming procedures. Thus, it is essential to develop methods that allow a fast adaptation to part geometries and production conditions as well as possible quality control. To tackle these problems, this work addresses novel strategies for robot programming and post-spray analyses. Here, the developed application can handle complex parts of arbitrary geometry in the form of CAD files to generate precise spray paths. Robot offline programming allows for process simulation, analysis and optimization. Robot kinematics was employed to evaluate the effect of the planned spray paths on the spraying process. By optical scanning profilometry, the layer-by-layer deposit build-up could be monitored for quality control, as well as for the determination of the final overall coating thickness. To validate the capability of the proposed strategy, the entire procedure was tested by cold spraying onto a complex workpiece. The results show that the proposed method enables a fast generation of the required paths and allows for accurate transfer to the spray procedures. Different path planning ways influenced the robot performance and thus the deposition. Based on the universal layout of the applied methods, the strategies can also be applied for thermal spraying in general, considering individual boundary conditions. With respect to cold spraying, the implementation framework of this study provides a good basis for part repair and additive manufacturing.
•A new fast, universal, and accurate implementation strategy for thermal and kinetic spraying processes.•Computerized spray path planning and generation method for complex parts.•Online monitoring of the deposit allows for non-destructive measurement and control.•Applying robot kinematics to evaluate the effect of spray path on the spraying process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
During cold dynamic gas spray additive manufacturing, the thermal field within particles is generally simplified by a state of an instantaneous uniform distribution over the particle's media at any ...position inside and outside the De-Laval nozzle. This paper addresses critical discussions using analytical and computational analysis of the transient heat transfer within the solid particles due to the convective exchange with the flowing gas. An analytical criterion depicts conditions of instantaneous uniform temperature over the range of typical cold spray data including various particle thermal conductivity, particle size range, dragging velocities, gas nature and gas setting conditions. The analytical depiction draws the conclusion that, during cold spraying, the temperature field within particles is mostly instantaneously uniform. The notion of instantaneousness is further investigated via computational analysis of the transient thermal gradient regimes within particles. The phenomenological computations enable to characterize the duration of the transient stage prior to the state of uniform temperature. Comparisons with analytical particle's residence time using various scales of travelled distance give a more relevant notion of instantaneousness. The particle temperature is not strictly instantaneously uniform. However, such instantaneousness prevails for a covered distance unit of 1 mm which is widely enacted in the literature to compute the particles temperature during cold spraying. As conclusive remarks, issues due to this instantaneousness of the particle temperature are reviewed and suitable alternatives for efficiently heating the particles during cold spraying are reported.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
This paper investigates the effect of laser scanning velocity on the structural changes and mechanical properties of a H13 steel part treated by laser surface remelting. A high energy ...density laser with a large laser beam was used to improve the processing efficiency. The room temperature phases are dominated by martensite, retained austenite, and carbides. The laser treatment effects under various exposition conditions are compared in terms of heat affected depth, surface topography, and mechanical properties. The strengthening mechanisms include grain refinement, dislocation and precipitation strengthening, which act simultaneously during the laser remelting process to confer a high hardness at the surface of the H13 steel workpiece. Due to its higher yield strength and lower elongation, failure in the remelting zone occurred at the grain boundaries of the dendrites and in between the heat affected zone (HAZ) and the parent metal (Base Metal). These results can support the mass production of surface hardened H13 steel moulds using a laser treatment (high laser density and large laser heat source) with apprehensible changes of properties.
Achieving high deposition efficiency (DE) is a current challenge of cold spraying metallization of polymers for developing surface function such as a conduction performance. Low-pressure cold ...spraying (LPCS) has been explored for that purpose but meets DE limitation less than 50% generally. This paper focuses on the possibility to overcome this issue, but using high-pressure cold spraying (HPCS). The anchoring of the copper powders onto the PEEK substrate is not difficult, but the deposition can fail during the coating build-up. A high pressure of 2.5 MPa without a gas preheating does not produce a coating build-up. Higher chamber pressures are required, but this implies to increase the gas temperature up to 400 °C to reach high deposition efficiency up to 70%. However, the absorption of the impact energy by the PEEK substrate during the collision of the powders generates an intermediate weakly bonded layer which is characterized by a decohesion between weakly deformed powders. This structure impairs the integrity of the coating during the additive deposition. Spalling damage occurs. Therefore, the deposition becomes very sensitive to delamination issues to overcome.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper investigates a current challenge that enables the hybridization of different materials using a solid-state additive principle. We investigate the suitability of such a principle to easily ...and efficiently grow a metallic electrically conductive coating on a polymer substrate. The additive principle is obtained using the high-pressure cold spraying (CS) method whose literature does not include an achievement as suggested in this paper, that is, to obtain a good conductive copper coating onto polymer with a very high deposition efficiency by tuning the effect of the stand-off distance, transverse speed of the nozzle, and temperature of the carrier gas on the deposition efficiency (DE) in order to overcome delamination and erosion, and thus to improve the DE. A good coating formation up to 400 µm can be obtained, which implies that a standoff distance higher than 100 mm is needed, since both a high gas temperature (400–500 °C) and high gas pressure (30 bars) are required. A nozzle scanning velocity in the range of 200–300 mm/s gives the highest DE. The results reveal that the Cu coating on PEEK reaches a DE up to 91%, leading to an electrical conductivity up to 60% IACS (International Annealed Copper Standard). Thus, parametric analysis, along with the deposition optimization, promises to be feasible for the future in terms of DE improvement along with a good electrical conductivity in CS.
Cold gas dynamic spraying is a solid-state processing technique that is particularly attractive for surface coatings, 3D near-net shape additive manufacturing, and component repairs with an advantage ...of high-deposition efficiency. This technique has the sustainable potential to change the future industrial and manufacturing environment, especially in the fabrication process of complex flight-critical components that are made of aluminum. This paper investigates the microstructure of aluminum coatings generated onto a commercial Al plate called FORTAL (Al 7075-T6) via cold spraying using helium as the propellant gas. Three Al coatings (pure Al, AlSi10Mg, and Scalmalloy) are compared under a similar deposition condition. The top view of the coating revealed the highest deformation (high flattening) in the case of pure Al powders, whereas both the AlSi10Mg and Scalmalloy powders exhibit less flattening. The cross sections show fine equiaxed grains within the pure Al coating and extremely fine grains for both the AlSi10Mg coating and the Scalmalloy coating, with more extremely refined grains within the Scalmalloy coating. These results suggested an onset of recrystallization within the Al coating that is attributed to the heat generated by the strong plastic deformation. Less thermally activated recrystallization occurred within both AlSi10Mg coating and Scalmalloy coating due to their stronger mechanical properties. The structure rather resulted from the dynamic due to the high strain rate collision. The extremely fine structure is mostly at the powder/powder interface within the Scalmalloy coating and is developed towards the powder region which is also within the AlSi10Mg coating. Better plastic deformation occurred within the AlSi10Mg powder compared to the Scalmalloy powder that have a higher mechanical resistance. Together, these results evidence a limited thermally activated recrystallization within the Al alloys despite the highest deposition condition being used. The pure Al powders can also achieve a state of equiaxed fine grain due to the better plastic deformation.
Magnetic pulse welding (MPW) is a solid state joining process, successfully utilized to join dissimilar metals. This advantage attracted manufacturing industries to fabricate hybrid materials to ...attain materials with a combination of multiple attributes. The high speed impact during the welding process causes various interfacial phenomena, which have been reported in previous research studies. Combined high speed collision, Joule heating due to eddy current and plastic heat dissipation cause noticeable heating in the workpiece. The heating from the plastic work and collision energy could particularly be significant at the vicinity of the interface compared to other regions of the workpiece. The Joule heating due to eddy current affects the entire workpiece that is prominent before the collision. There is a sharp increase of the temperature at the onset of weld formation due to dissipation of plastic work during the collision. 3D simulations of coupled electromagnetic-mechanical-thermal were carried out to investigate the heating due to the combined Joule heating and plastic dissipation. A case study of MPW, consist of a one turn coil combined with a field shaper, is used to investigate the welding process. The simulations were performed using LS-DYNA®, which has the capability of using both finite and boundary elements to solve the thermo-mechanical problem during electromagnetic forming. The predicted temperature distributions from numerical simulations show expected phenomena of Joule heating and plastic heat dissipation while the analytical approach used to estimate the localized increase in temperature due to supersonic gaseous compression. Minimizing the heating effect by identifying the influencing factors could help to optimize and control the quality of the magnetic pulse welded parts.
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