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Green Applications with an Advanced Manufacturing Method
Published in Catalin I. Pruncu, Jamal Zbitou, Advanced Manufacturing Methods, 2023
Koray Kılıçay, Salih Can Dayı, Esad Kaya, Selim Gürgen
With the increase in studies both in the industrial field and in the academic world, the application potential of CS technology has started to be understood more clearly, and its applicability, advantages, and disadvantages have been revealed. Research and studies related to which materials it can be applied to, optimum process parameters, postprocess performance are increasing gradually. Thanks to the repair of metallic-based materials, especially used in aviation, automotive, maritime, and other industrial areas, product lifespan increases. This situation saves the need for remanufacturing material, time, and energy. For this reason, the CS repair method is considered a green method, as it eliminates the harmful effects on the environment. At the same time, the fact that it can be used for additive manufacturing, which is an advanced manufacturing method, makes CS technology more interesting. Along with the production advantages it provides, the cold spraying method also has important advantages such as reducing environmental impacts, economic efficiency, and safety.
Composite Processing Techniques
Published in Andy Nieto, Arvind Agarwal, Debrupa Lahiri, Ankita Bisht, Srinivasa Rao Bakshi, Carbon Nanotubes, 2021
Andy Nieto, Arvind Agarwal, Debrupa Lahiri, Ankita Bisht, Srinivasa Rao Bakshi
Thermal spray is an industrial scale processing technique that can be used to produce coatings or free standing structures. In thermal spray techniques, material to be sprayed is fed into a heat source in the form of fine powder or wire, where it is converted into a molten or semi-molten state that is accelerated by a carrier gas and made to impinge on a substrate. The molten/semimolten particles strike the substrate and form splats. Accumulation of splats layer by layer results in formation of a coating. Thermal spray is a nearly 100-year-old process. Quoting from the Calendar of Patents Records published in the journal Nature, “The modern metal-spraying process for coating iron and steel is largely due to the Swiss chemical engineer, Dr. M. U. Schoop, whose first patent was applied for in Germany on April 27, 1909. The English patent was granted the following year” [62]. The technology of thermal spraying has vastly improved in the last three decades due to much research, resulting in newer applications. Thermal spray coatings are used in a variety of industries like automobile, aerospace, chemical, and heavy machinery for protection from wear, corrosion, and high temperature environments. Based on the source of heat, the techniques can be classified as wire arc, flame spray, plasma spray, high velocity oxy-fuel spray, and detonation gun spray process. In certain spray processes, there is no thermal energy input like cold spraying. A comparison of the various processes based on the gas temperatures involved and the particle velocities attained is shown in Figure 3.9.
Fluid Spreading, Film Drawing, and Surface Coating
Published in Kleinstreuer Clement, Modern Fluid Dynamics, 2018
Basic spray processes are greatly dependent on the atomizer design and function. More elaborate techniques, collectively known as thermal spraying, are surface-coating processes whereby melted (or just heated) coating material, such as metals, ceramics, or plastics in powder or liquid form, are sprayed over large surfaces, generating micrometer to millimeter thicknesses. A common variant of thermal spraying is plasma spraying, in which a high-temperature (&>10,000 K), high-velocity (&>100 m/s) fluid-particle stream is generated by mixing the coating material into a plasma jet emanating from a plasma torch (Pawlowski, 2009). In contrast, cold spraying, in which coating particles are accelerated by the carrier gas through a converging-diverging (de Laval) nozzle, has gained numerous applications. If the powder-particle impact velocity exceeds a threshold value (300–1200 m/s), these particles deform and adhere to the target surface. Using kinetic energy (rather than heat) for deposition, thermal stresses, surface-oxidation, and certain chemical reactions can be avoided (see Moridi et al., 2014 for details). More recently, simple one-step spray-coating processes have been developed, using a spraying gun loaded with stearates or silica nanoparticles, to create (artificial) super-hydrophobic surfaces. Such coated (metal or plastic) surfaces can be self-cleaning, antifogging, or anticorrosion, or can separate two fluids (Li et al., 2015).
Nanoprotection from SARS-COV-2: would nanotechnology help in Personal Protection Equipment (PPE) to control the transmission of COVID-19?
Published in International Journal of Environmental Health Research, 2023
Zhi Xin Phuna, Bibhu Prasad Panda, Naveen Kumar Hawala Shivashekaregowda, Priya Madhavan
The super hydrophobicity of copper nanoparticle surfaces discussed above was developed from conventional spraying technique (Meguid and Elzaabalawy 2020). A simpler yet advanced technique called cold spray technique can also be used to develop self-disinfecting surfaces. Hutasoit et al. (2020) has developed copper-coated surface fabrication by cold-spray technique that has shown to inactivate 96% of SARS-CoV-2 within two hours and reduce the virus lifetime to less than five hours (Hutasoit et al. 2020). Furthermore, their studies demonstrated that cold-sprayed copper coating on push plate only required approximately 17 minutes from spraying onto redeployment onto a door. However, in Meguid and Elzaabalawy (2020) studies, the copper nanoparticles surfaces fabricated from conventional spraying method required an hour of drying process at 121°C (Meguid and Elzaabalawy 2020). Cold spraying technique uses the acceleration of small particles in a solid state to high velocities, to reach rapid deposition on substrate materials. As compared to a heat source in thermal spray, the bonding of particles to a substrate is achieved using the kinetic energy of particles in cold spraying technique. This has provided an advantage for cold spray when exploiting temperature-sensitive, oxygen-sensitive, phase-sensitive as well as nano-structured materials (Zahiri et al. 2008). Thus, incorporating cold spraying technique in deposition of nanomaterials onto super hydrophobic surface can be developed as an effective self-surface disinfectant.
Substrate pre-treatment by dry-ice blasting and cold spraying of titanium
Published in Surface Engineering, 2018
During cold spraying, powder particles are accelerated to a velocity higher than its critical velocity (a velocity results in a transition from erosion of the substrate to deposition of the particle, higher than which only those particles achieving a velocity could be deposited to form a coating) by injecting into a high-velocity stream of gas accelerated through a converging-diverging nozzle and then impact upon suitable substrates. Li et al. [6] have found that two distinguishable top and inner regions exist in the titanium coating, which are characterised by the porous and dense microstructures resulting from the accumulative effect of tamping on the top porous region by the successive impact of following particles. Hussain et al. [7] have analysed the impact behaviour of titanium particles on different ferrous substrates and have found that relatively harder ferrous alloys might promote jetting of Ti particle upon impact. Gardon et al. [8] have reported that it is possible to coat biocompatible polymer implants with titanium leading to thick, homogeneous and well-adhered coatings using cold spraying.
Review on the Preparation and High-Temperature Oxidation Resistance of Metal Coating for Fuel Cladding Zirconium Alloys
Published in Nuclear Science and Engineering, 2023
Ling Sun, Yuchen Xiao, Weijiu Huang, Baifeng Luan, Baoan Wu, Huiyi Tang
Cold spraying replaces the necessary thermal energy for high-speed kinetic energy in traditional thermal spraying, which greatly reduces the influence of heat on the coating and substrate and provides a wide range of potential application. The CS process has the advantages of low deposition temperature, high deposition rate, low cost, small thermal impact on the substrate, uniform distribution, and basically no oxidation of the coating, but the coating surface still exhibits relatively high roughness.[25]