Browse Topic: Coating processes
Cold spray deposition is a kinetic-based deposition method that uses an inert gas flow to accelerate particles, where kinetic energy causes plastic deformation upon impact with a substrate, as discussed in Reference 1. Cold spray has been investigated as a method to deposit metal coatings on polymer-based composites, such as aerospace carbon-fiber-reinforced plastics (CFRP's), as discussed in Reference 2. These methods also exhibit low deposition efficiency (15-45%) as shown in Reference 3. In this work, to achieve high deposition efficiency and create an erosion-resistant coating, we use metal-polymer composite powders for cold spray, to make polymer-on-polymer bonding the dominant and effective bonding mechanism; this method lowers impact velocities relative to pure metal deposition to avoid substrate damage. The polymer can also lower the effect of material mismatch, while the nickel can help enhance the erosion performance of the final coating above that of pure polymer. This paper discusses the development of the cold spray deposition process, sample post-processing, erosion testing, and characterization of the samples. The results validate that this method successfully creates a method of depositing a coating with erosion resistance approaching that of bulk titanium without substrate damage on PEEK substrates. Further work is needed to address the issues with depositing on CF-PEEK substrates.
In the design of Rechargeable Energy Storage System (RESS) structures, including battery trays, module side plates, and end plates, there are multiple conflating factors, including: Mechanical requirements necessitating the use of electrically conductive materials (steel and aluminum); proximity between battery module structure and battery cells, necessitating the use of electrical isolation coatings; and, module and pack designs that retain cells via the use of Structural Adhesive Material (SAM). Inherently, with this design approach, organic coatings are placed in a new and perilous position. In a sense, the coating becomes a supplement to an adhesive. As Computer-Aided Engineering (CAE) virtual analysis tools become more sophisticated, there is increasing reliance on these tools to predict the occurrence of structural failures in various load cases. Factors in test method, paint pretreatment, and topcoat affecting adhesion of organic coatings in structural adhesive joints are discussed, including: Adhesive sample preparation; adhesive selection, coating film pretreatment; age of pretreatment bath; acid cleaning; substrate material type (steel vs. aluminum); substrate product form effects within aluminum, and coating thickness. This information is useful for organic coating process development on metallic substrates. It is especially useful for material constructions requiring paint in contact with structural adhesives, as in these joints, paint adhesion is often a limiting factor on the performance of the structural adhesive. The characterization and optimization of this interface is especially important for EV battery modules & packs.
Maintaining the operational readiness of military helicopters demands repair solutions that are fast, reliable, and adaptable. This paper presents the integration of Gamma Alloys' advanced metal matrix composites (MMCs) into additive manufacturing (AM) techniques - specifically Cold Spray and Friction Stir Additive Manufacturing (FSAM) - as a transformative approach to helicopter repair and replace for the US Army.
The solar-based hybrid automotive vehicle represents a trend marked by technological excellence, offering an efficient, cost-effective, and eco-friendly solution. Besides, the enhancement of solar absorption due to poor weather is influenced by poor solar power with reduced photocurrent density. This research focuses on enhancing the solar power and photocurrent density of conventional solar cells featuring aluminium-doped zinc oxide thin films (AZO) using the Mist Chemical Vapor Deposition (MIST CVD) process with a zinc acetate precursor solution processed at temperatures ranging from 200 to 400°C. To investigate the effect of AZO on the functional behaviour of solar cells, microstructural studies utilizing scanning electron microscopy and X-ray diffraction reveal the concentration of AZO and the alignment of Al/ZnO peaks as even. As a result, this research demonstrates a 21% increase in solar power output compared to conventional Cadmium Telluride (CdTe) cells, with an improvement in photocurrent density of 1.24 mA/cm2. This advanced solar cell technology is recommended for use in electric vehicle (EV) applications.
As “point of need” additive manufacturing emerges as a priority for the Department of Defense (DoD), Australian 3D printing provider SPEE3D is one of several companies demonstrating that its machines can rapidly produce castings, brackets, valves, mountings and other common replacement parts and devices that warfighters often need in an on-demand schedule when deployed near or directly within combat zones. DoD officials describe point of need manufacturing as a concept of operations where infantry and squadron have the equipment, machines, tools and processes to rapidly 3D print parts and devices that are being used in combat. Based in Melbourne, Australia, SPEE3D provides cold spray additive manufacturing (CSAM) machines that use a combination of robotics and high-speed kinetic energy to assemble and quickly bind metal together into 3D-printed parts without the need for specific environmental conditions or post-assembly cooling or temperature requirements. Over the last two years, the company has participated in military point of need manufacturing challenges and demonstrations with military units from the U.S., UK, Australia and Japan among others.
Graphene has been called “the wonder material of the 21st century.” But graphene has a dirty little secret: it’s dirty. Now, engineers at Columbia University and colleagues at the University of Montreal and the National Institute of Standards and Technology are poised to clean things up with an oxygen-free chemical vapor deposition (OF-CVD) method that can create high-quality graphene samples at scale. Their work, published in Nature, directly demonstrates how trace oxygen affects the growth rate of graphene and identifies the link between oxygen and graphene quality for the first time.
University of Wisconsin–Madison engineers have used a spray coating technology to produce a new workhorse material that can withstand the harsh conditions inside a fusion reactor.
This study delves into the innovative realm of synthesizing surface alloyed materials by utilizing copper-based metamorphic powders subjected to high-intensity electron beam irradiation. The process involves depositing metamorphic particles onto a stainless-steel substrate, and subsequently exposing the assembly to a powerful electron beam, resulting in the development of distinct surface alloyed layers. A notable advancement was achieved by introducing a second layer of metamorphic powders over the existing alloyed layer, followed by further treatment with the electron beam. The alloyed layers, characterized by a volumetric concentration ranging from 60 to 67%, exhibited a fascinating phenomenon— the formation of abundant borate crystals with the chemical formula Al2.56Fe1.75Ni0.84. This crystal presence significantly elevated the hardness of the surface alloyed layers, showcasing an impressive five to sevenfold increase compared to the substrates. Importantly, the alloyed layers demonstrated remarkable thermal stability, successfully enduring a rigorous test at 450 degrees Celsius. The subsequent Vickers hardness measurement, registering at 300 VHN, underscores the substantial and enduring hardness achieved. Beyond these core findings, this study sheds light on the potential of alloyed-surface materials in demanding applications requiring robust heat resistance and exceptional wear resistance. The methodological synergy of metamorphic powders and electron beam irradiation serves as a promising avenue for the development of advanced materials with heightened mechanical properties. Furthermore, this research opens avenues for future investigations into the specific structural and compositional attributes contributing to the observed material enhancements.
Naval Air Systems Command Naval Air Station North Island, CA (619) 545-3415
Simulation tools play a significant role in the automotive industry due to their cost-reducing capabilities in new model development. Computational Fluid Dynamics (CFD) is extensively utilized in various applications, such as vehicle aerodynamics and engine thermal management. However, its application in manufacturing engineering is not yet widespread. One crucial process in automotive manufacturing is the application of the base coat, which provides protection for the final paint layer. This process involves three key steps: bodywork immersion, electrophoretic deposition (E-coat), and bodywork removal from the bath. Each of these steps can be evaluated using appropriate CFD models. During the immersion step, the primary objective is to minimize the presence of trapped air. In the E-coat step, the focus is on controlling the paint layer thickness on the Body-in-white (BIW). Lastly, the drainage analysis aims to minimize the retention of bath fluid, thereby preventing contamination in subsequent baths. In this study, we propose a methodology utilizing Simcenter STAR-CCM+ as the CFD code and a generic car geometry to evaluate these three painting stages. Our methodology demonstrates the effectiveness of Simcenter STAR-CCM+ in predicting the behavior of the BIW throughout the painting process. By simulating the evolution of physical phenomena, our methodology provides valuable information regarding the presence of trapped air during the dipping stage, the thickness of the paint layer during E-coat, and the volume of retained liquid during drainage. This approach offers a promising means to reduce prototype investments by anticipating the behavior of the BIW during the virtual painting process. As a result, potential quality issues can be identified and rectified by making necessary component changes. Moreover, this methodology can be employed to optimize the painting process itself, including the adjustment of parameters related to the generated electric field and the movement of the BIW within the bath. These optimizations aim to enhance energy efficiency and accommodate changes in line speed, maintenance of anodes, and alterations in chemical characteristics of the bath. In conclusion, the use of CFD simulations, specifically employing the presented methodology with Simcenter STAR-CCM+, proves to be highly beneficial in evaluating and optimizing the three critical stages of the automotive painting process. This approach enables the identification and mitigation of quality problems, offers cost savings in prototype development, and facilitates process adjustments for improved efficiency and adaptability.
Graphene is a two-dimensional carbon material made of carbon by covalent bonds, where carbon atoms are arranged in a honeycomb lattice. Graphene has promising electronic and mechanical properties. There are many processes available for the formation of the graphene. CVD (Chemical Vapor Deposition) process for the formation of graphene over the metal surface is most compatible. Graphene is being investigated for its application in space electronics. In space, there are many irradiation particles and waves like x-rays, gamma rays, alpha particles, and beta particles. Single particle like neutron can create single event upset in electronic devices. Graphene can work as a radiation shielding material. Graphene-metal, graphene and epsilon near zero metamaterials structure can be used for electromagnetic wave absorbent.
NASA instrumentation is at risk for contamination from dusty space environments. Additionally, contamination from water and ice buildup can affect instrumentation function. Researchers at the Goddard Space Flight Center have developed a viable dust, water, and ice mitigation optical coating for space flight, aeronautical, and ground applications. The innovation of the LOTUS coating prevents contamination on sensitive surfaces, like optics, that cannot be cleaned during space missions.
Engineers, managers, technicians and other automation professionals at most manufacturers understand the value of pretreating metal surfaces of parts to remove corrosion, grease, residue, old coatings, or to roughen the surface of metals prior to coating. By ensuring the items are cleaned down to bare metal, manufacturers can avoid costly warranty issues that result when coatings peel, flake, bubble, or otherwise fail prematurely.
Chemical Vapor Deposition (CVD) and Atomic Layer Deposition (ALD) processes deposit material on all surfaces in a process chamber. Over time, the thickness of these deposits increases to the point that material begins to delaminate, producing gas-phase particulates that negatively impact process yield. Remote and in situ chemical etching processes are used to periodically remove these deposits from chamber walls, maintaining chamber cleanliness.
Electroplating is a process whereby an object is coated with one or more relatively thin, tightly adherent layers of one or more metals. It is accomplished by placing the object to be coated on a plating rack or a fixture, or in a basket or in a rotating container in such a manner that a suitable current may flow through it, and then immersing it in a series of solutions and rinses in planned sequence. The advantage to be gained by electroplating may be considerable; broadly speaking, the process is used when it is desired to endow the basis material (selected for cost, material conservation, and physical property reasons) with surface properties it does not possess. It should be noted that although electroplating is the most widely used process for applying metals to a substrate, they may also be applied by spraying, vacuum deposition, cladding, hot dipping, chemical reduction, mechanical plating, etc. The purpose for applying an electroplate and the metals used for various applications follow.
This specification establishes requirements for pressure-sensitive adhesive tape designed for masking and color separation during aircraft painting operations.
Items per page:
50
1 – 50 of 429