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Phase change materials are the category of materials that release or absorb enough energy during phase change transformation to provide heating or cooling. Divided into two principal classes of organic and inorganic, these materials find a wide range of uses in commercial applications of casting where stable temperature and heat storage are a requi...
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... The other half of the wooden component kept just over the levelled surface embedded other half of the wooden component sample over the one embedded in the cope sandbox. Similarly put the sand over the component in the drag box like previously [58]. After putting sand up to a level where it can see the wooden sample component, the use of a sprue pin for the riser and the pouring cup is employed. ...
... Gating systems are highly important to minimize the turbulence, erosion of the internal sand walls, and removal of inclusions are also major factors why gating systems are emphasized in sand casting just before the final process. Metal wastage is also a major issue that can occur if there is no appropriate Fig. 2 a Sand casting process, b sand casting setup [58] gating system; a faulty one may also lead to the same. The gating system is responsible to initiate directional solidification, and also appropriate gating systems avoid the defect which is usually experienced in sand casting also known as misrun; due to an instant decrease in temperature of the pouring molten metal at the entrance point in the pouring cup, it may experience freezing at an early point and not filling the mold cavity [59]. ...
... The next task is to melt the metal in a furnace until it becomes liquid. Take care of the gating system, and also, this will be useful to avoid mixing sand [58] particles into the molten metal and also will avoid misrun. The next step is putting the molten metal through the pouring cup. ...
The sand-casting process is predominantly used worldwide, especially in small-scale industries. It is very important for small component manufacturing and is one of the simple metal casting methods. However, the sand-casting process has some flaws, which also sometimes lead to a higher cost in some cases, especially the disadvantages like the surface finishing and the porosity add up to higher cost in the cases of complicated castings and their machining. This review investigates various research works done in and around the sand-casting process and tries to implement the parameters to obtain an appropriate final product from the sand-casting process, focusing on the intermediaries involved during the sand process casting and using them efficiently. These intermediaries may include the components used during the sand-casting process, predominantly sand, the metal used, the mold used for making the cavity, the chill used for promoting homogeneous nucleation, etc. Another focus is on decreasing the wastage of resources during the process. The discussed parameters will attempt to provide future directions to maximally control the disadvantages to some extent in the current process.
... A fundição é muito importante para a reciclagem de metais, pois toneladas são fundidas todos os dias nas fábricas (Chadha et al., 2022). O alumínio é um metal que possui uma ligação forte com o oxigênio, formando, quando submetido a altas temperaturas (acima de 700°C), uma camada de óxido de alumínio (Valentim; Oliveira, 2011). ...
O alumínio tem sido na atualidade um dos metais, de fácil acesso, versáteis para aplicações e desenvolvimento de diversos produtos. Suas propriedades físicas e químicas o tornam uma escolha segura para situações que exigem resistência mecânica, leveza, boa condutividade elétrica e baixa suscetibilidade à corrosão. A partir de uma revisão de literatura, este artigo tem por objetivo fazer uma retomada do seu contexto histórico entregando ao leitor uma clara ambientação do seu desenvolvimento, ao passo que demonstra seus processos de transformação, além de seus usos e potencialidades. A partir de sua caracterização teórica, o alumínio de segunda geração, pós-reciclagem, tenta competir em igualdade com o alumínio de primeira geração, tendo ao seu favor a economia energética. O alumínio está claramente tomando o lugar do cobre, fato que ambientalmente é saudável levando-se em consideração a disponibilidade global de ambos os metais. Infelizmente, os processos de reciclagem não têm acompanhado a crescente evolução, deixando seus atores à margem da sociedade em muitos casos. Tornar estes processos eficientes, rápidos e agregar valor ao reciclado pode ser uma oportunidade para melhorar o contexto social de várias comunidades de catadores e recicladores. Como resultado desta pesquisa, conseguiu-se observar que: em função da necessidade do aumento da reciclagem e seu funcionamento em circuitos fechados para uma melhor qualidade do reciclado disponibilizado; além da necessidade do aumento da disponibilidade do alumínio de segunda geração; as novas tecnologias como: o reconhecimento visual eletrônico automático, voltado para a etapa da reciclagem; atomização e processos de manufatura 3D, voltados para as etapas de produção; e a soldagem laser, voltada para a parte de união dentre partes, ou filamentos, podem propiciar, ao alumínio de segunda geração, qualidades técnicas muito próximas ao metal original.
... In recent decades, phase change materials (PCMs) have emerged as an attractive alternative for thermal control and energy storage in many applications [1], ranging from manufacturing [2], renewable energy [3] or net-zero energy buildings [4,5], to food storage [6] and electronics [7,8]. Another specialized area of application is space exploration [9,10], with the unique operational constraints of reduced gravity, which leaves conduction as the principal mechanism for heat transport [11], and the cyclic exposure to solar radiation, which may lead to extreme temperature fluctuations [12]. ...
In this work, we analyze the thermocapillary-enhanced melting of n-octadecane driven by a constant heat flux, applied at the free surface, in microgravity. The material is enclosed in an open rectangular container of dimensions 2𝐿 × 𝐻, and its solid-to-liquid transition is described using an enthalpy-porosity formulation of the Navier–Stokes equations, assuming laminar and incompressible flow. We study the influence of key governing
parameters, including the effect of the heated lengtĥ ∈ (0, 1], the applied flux 𝜙 ∈ (0, 8], and the container aspect ratio 𝛤 ∈ [1.5, 22.8]. Heat transport is analyzed by comparing the thermocapillary-enhanced process with that driven solely by conduction, and quantified by the enhancement ratio G, which simply compares melting times in each scenario. We find that G increases with 𝜙 and 𝛤, and is maximum at an optimal heated
length ≃ 0.5. Compared to previous works on the melting of n-octadecane in microgravity, the associated enhancement G is more moderate in this system, and oscillatory thermocapillary convection is not observed over the range of parameters explored.
... Nowadays, PCMs are widely used to minimize the waste of heat and maximize efficiency in many systems, playing a fundamental role in the fight against climate change. Manufacturing [4], food storage [5], netzero energy buildings [6,7], renewable energy [8], or electronics [9,10] are just a few examples of application. ...
... Then, ̄is applied as a constant lateral flux via the boundary condition (4). In addition, we use the liquid fraction L: ...
... Recall that, the energy absorbed by the PCM is primarily stored in the form of latent heat; the absorption via sensible heat is somewhat limited, given that the maximum temperature in the PCM is bounded by . With lateral flux, on the other hand, the heat absorbed by the PCM is constant and equal to ( ), as imposed by the boundary condition (4). Consequently, the quantity of energy stored increases steadily with time, fact that is reflected in a linear increase of L and the associated progression of the solid/liquid front; see Figs. 3 and 4, respectively. ...
We numerically investigate the melting dynamics of n-octadecane in a rectangular container that is subjected to a constant lateral flux and is open to air in microgravity. As the melting progresses, the temperature gradient existing at the open boundary drives thermocapillary flow within the liquid phase and modifies the phase change dynamics. We conduct a parametric study varying key dimensionless parameters-the Marangoni and Stefan numbers, and the aspect ratio-and compare the associated temporal dynamics with those observed in the (so-called) reference case, where heat is transferred solely by conduction, and with those driven by isothermal boundary conditions [1,2]. Compared to the isothermal case, where the overall effect of thermocapillary flows is to accelerate melting by a factor up to 20, the analogous contribution with lateral flux is about one order of magnitude smaller, with values up to 2.8. Finally, we perform spectral analyses of the oscillatory standing wave and hydrothermal traveling wave modes that eventually appear during melting for large applied flux. The critical Marangoni number (Ma_cr) is estimated considering the characteristic dependence ∝ (Ma − Ma_cr)^0.25 of the (so-called) oscillatory mode contribution.
... The sand mould is split open to release the casting after the metal has cooled to room temperature. The schematic illustration of sand casting is shown in Fig. 1 [6]. ...
Casting is an especially flexible process that can be utilized by foundries for production on a large scale. Due to their importance as a source of castings, foundries now play a significant role in the industrial sector. The production of excellent castings at the lowest possible cost is the ultimate aim of the manufacturing sector. Undesirable imperfections in the metal casting process are known as defects. A number of issues that are process-related are the reason for the defects. A few defects can be tolerated while others can be fixed, or they can even be eliminated with good moulding technique. These imperfections develop as a result of a few production cycle processes that are not effectively monitored. Sand casting company efficiency is negatively affected by poor casting. For strong castings, the challenging casting defect conditions must be identified and reduced. By reducing casting defects throughout manufacturing, the foundry sector can improve its level of quality. The primary objectives of this study are to identify the significant sand casting defects and analyze the preventative measures to reduce the defects. In this work, efforts are undertaken to identify technically feasible remedies for minimizing a variety of casting weaknesses and improving casting quality.
... Melt undergoes various phase transformations over time during the casting process [1-2]. Since these processes are accompanied by significant temperature differences in the volume of the casting produced, depending on the casting method, taking into account the type of material, phenomena such as shrinkage, heterogeneity of the structure and other casting defects are possible [3][4][5][6][7]. These undesirable phenomena may be the result of non-compliance with the casting process. ...
The process of phase transition of a liquid metal to a solid state during cooling was modeled in the article. Dependences of the change in the Peclet number, enthalpy, phase transition between liquid and solid phases and the temperature gradient of melt at casting speeds of 5, 50 and 200 mm/s were obtained. It is noted that at higher casting speeds, the investigated process parameters practically do not change at the temperature transition zone half width of 75 and 150 K.
... The use of PCMs, therefore, opens the possibility of new passive thermal control devices and energy storage applications. Examples of current relevance can be found in different technological fields ranging from manufacturing [2], food storage [3] and net-zero energy buildings [4,5] to renewable energies [6], electronics [7,8] and space exploration [9,10]. ...
We explore the preliminary design of a space habitat thermally controlled using phase change materials (PCMs). The PCM is used to maintain a suitable, habitable temperature inside the habitat by isolating it from the external solar radiation. The system is studied numerically considering only diffusive heat transport (conduction), a scenario with practical application to microgravity or reduced gravity environments. The system dynamics are explored for a wide range of governing parameters, including the length of the PCM cell L, the thermo-optical properties-absorptivity α and emissivity ε-at the external boundary of the habitat wall exposed to solar radiation, the eclipse (illumination) fraction τ e (τ i) of the solar cycle, and the PCM used. We find that the thermo-optical properties at the external radiated boundary, characterized by the absorptivity-emissivity ratio (α/ε), play a key role in the system response and largely define the optimal design of the habitat. This optimum balances the heat absorbed and released by the PCM during repeated illumination and eclipse cycles.
... Compared to a convex (T1) tool using a tool with three concave arcuate grooves (T3 and T4), the grooves (T3 and T4) reduce material mixing throughout the intersections, especially at the edges. Encourage [29,39]. The basis for the two-layer, friction-stirred, one-pass additive build made using T3 and T4 is asymmetric. ...
Friction stir welding (FSW) is a method used to weld together materials considered challenging to weld by fusion welding. FSW is primarily a solid-phase method that has been proven efficient due to its ability to manufacture low-cost, low-distortion welds. The heat build-up is usually the result of friction between the workpiece and the tool in friction stir welding process. The integration of the process in the space welding is a boon, because of not reaching the melting temperature of the metals and not involving any foreign material, unlike TIG/MIG processes, give it an edge over other processes. This research will utilise assumed space and on-ground parameters using 4 different simulation software, to perform structural analysis and simulation of the welding process in ANSYS, ABAQUS, FUSION360, SOLIDWORKS to obtain an ideal result for understanding the feasibility of the process.
... The rise of a technological revolution will mold the way of development, service, and operations as we currently know it. The fourth industrial revolution (4IR) will expose unique and meaningful technological capabilities and improvements that would provide a transition for all industries to becoming well-planned, conservative, productive, sustainable, and self-sufficient [41,[73][74][75][76][77][78]. Industry revolution 4.0 with digitalization and IoT supports the union of devices, sensors, and information systems that form a group of more extensive intelligent networks. ...
This review deals with implementing technological advances in the manufacturing sector to implement sustainability. Integrating automated control tools into conventional manufacturing methodologies has significantly increased overall performance, productivity, and output. Moreover, the cost optimization and consumption of resources efficiently are achieved, and most industries are shifting gradually towards sustainable manufacturing. Digitalization in manufacturing contributes to environmental sustainability by boosting resource and information efficiency. Manufacturing and logistics operations intelligently linked across industry lines result in greater efficiency and an adaptive real-time lean manufacturing environment.
... Maintaining constant flow rates at all times is very important to regulate dilution and porosity. Even distribution of powder feed is also essential [19][20][21][22][23][105][106][107]. ...
Additive manufacturing (AM) has been gaining pace, replacing traditional manufacturing methods. Moreover, artificial intelligence and machine learning implementation has increased for further applications and advancements. +is review extensively follows all the research work and the contemporary signs of progress in the directed energy deposition (DED) process. All types of DED systems, feed materials, energy sources, and shielding gases used in this process are also analyzed in detail. Implementing artificial intelligence (AI) in the DED process to make the process less human-dependent and control the complicated aspects has been rigorously reviewed. Various AI techniques like neural networks, gradient-boosted decision trees, support vector machines, and Gaussian process techniques can achieve the desired aim. +ese models implemented in the DED process have been trained for high-precision products and superior quality monitoring.
