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Electropolishing in Practice
Published in Madhav Datta, Electrodissolution Processes, 2020
Metal fabrication processes such as stamping, grinding, machining, and heat treating all are employed to convert a metal bar, casting, or sheet into a finished part. As the metal is bent, ground, heated, and altered, the metal surfaces alter significantly. These alterations take the form of burrs, surface deformation and irregularities, scale, and embedded particulate, thus making the fabricated part venerable to degradation by corrosion. These imperfections may inhibit the functionality of the component. In many cases, these surface imperfections can be a focal point for infection or metal contamination. A combination of different metal finishing techniques is used to obtain a metal surface that is devoid of imperfections and contaminants. The essential criteria of the finishing operation are to provide improved surface smoothness, brightness, reflectivity, and cleanliness. Among the different finishing methods, mechanical and electrochemical polishing techniques are the two predominant techniques used in the metal finishing industry.
Multi-period additive/subtractive product platform design and inventory management
Published in International Journal of Production Research, 2022
Mostafa Moussa, Hoda ElMaraghy
The considered family consists of 4 product variants composed of 12 different features. Figure 4(a) shows the product variants, while Figure 4(b) shows the 12 features. Table 2 represents the overall dimensions of the considered variants. Table 3 shows the features from which each product variant is formed and the precedence relationship between the features of the gear shaft family. The DMD is utilised since many of the addition of features will be built on a non-planner surface. CNC turning and milling machines are required for cutting the cylindrical geometries and opening the gear teeth. The costs for mass producing additive manufacturing and subtractive manufacturing of features are shown in Table 4. These costs are determined based on quotas from the 3D Hubs network (Hubs Company 2020). The 3D Hubs is an online manufacturing platform that offers a range of manufacturing services such as additive manufacturing, sheet metal fabrication and CNC machining. It allows to get quotes to manufacture parts by uploading CAD models and specifying the manufacturing process type and the part material. The cost of manufacturing various features is based on manufacturing of steel alloy using CNC turning, CNC milling, and DMD processes (Hubs Company 2020).
Application of machine learning algorithm in the sheet metal industry: an exploratory case study
Published in International Journal of Computer Integrated Manufacturing, 2022
Ahm Shamsuzzoha, Timo Kankaanpaa, Huy Nguyen, Hoang Nguyen
Machine learning is also used to predict the defects of sheet metal forming processes (Deb, Ribeiro, and Prates 2018; Tsai and Chang 2018). Kwitek (2016) demonstrated how sheet metal fabrication machines can use machine learning in order to gain competitive advantage. He used machine learning to focus on predictive maintenance, which contributed to improving operations management. Hamouche and Loukaides (2018) applied machine learning to sheet metal forming, which is considered a critical component of modern manufacturing. In their study, a machine learning approach was used for the first time with the objective of identifying the manufacturing process, which formed a part solely from the final geometry. By implementing a mapping of the mean and Gaussian curvatures through machine learning, a high accuracy rate was established that automated the operational processes from the initial stage as design to manufacture, thus eliminating the requirement for human experts in matching each product with a suitable forming method.
Pnicogen bonds in complexes with CO and CS: differentiating properties
Published in Molecular Physics, 2019
Janet E. Del Bene, Ibon Alkorta, José Elguero
Carbon monoxide (CO) and carbon monosulfide (CS) are molecules with very different properties, even though oxygen and sulfur are contiguous in Group 16. This difference has been attributed to what has been called the anomalous behaviour of the elements of the second row of the Periodic Table, from Li to F [1,2]. CO is produced by the incomplete combustion of fossil fuels. It is a stable but highly toxic gas, and has a variety of applications, including its use in metal fabrication. It is also found with H2 in fuel gas mixtures which are used for heating. CO is a common ligand in transition-metal complexes. It is known experimentally that the gas-phase protonation of CO occurs at the C atom [3]. In contrast, CS is unstable as a monomer since it polymerises. It is found as an isolated monomer mainly in the interstellar medium [4]. Like CO, CS has been used as a ligand in transition-metal complexes [5].