Scrap Materials Research Articles

Investigation of Insulation Layers on Additive Manufactured Electrical Steel Laminations in Electric Motors

In this paper, the insulation properties of printed electrical steel laminations for high-efficiency electric machines are investigated. In contrast to conventionally produced electrical steel laminations made from rolled coil material, additive manufacturing from powder material allows extremely thin and complex near-net-shape geometries with no scrap material. At the same time, the printed electrical steel laminations offer the advantage that no additional cutting steps are required and specific material characteristics are adjustable which enables special machine modifications. To avoid global eddy current paths between the single sheet layers after the stacking process, the laminations must be insulated from each other in order to keep losses low, especially at high operating frequencies. This requires a sufficiently high surface insulation resistance on the sheets. Since the insulation coating cannot be applied continuously during rolling, as in conventional production, alternative approaches for application are required. The investigations characterize and evaluate potential insulation systems for additive manufactured laminations. The printed sheets are analyzed geometrically, electrically and metallurgically at first and characterized for the next process steps. Afterwards, potential insulation systems are analyzed and investigated in practical tests. The coating systems are characterized in terms of application, thickness, electrical and mechanical insulation properties, and options for further processing. This is crucial as the coating needs a sufficient level of adhesion to the substrate and allows successive bonding.

Input material reduction incentives versus scrap recycling for closed‐loop supply chains

Motivated by interactions with a major player in the aerospace industry, we consider the relationship between a supplier of specialty material forgings and a buyer that manufactures airplane components by extensively machining down these forgings as per component design specifications. Due to high material removal costs, the buyer prefers these forgings to be as similar in geometry and size to the component as possible, that is, near‐net‐shape. The supplier, by default, is unable to deliver such near‐net‐shape forgings as per technological constraints, but can utilize costly effort and/or invest in the required technologies to achieve such capabilities. By taking into account uncertainty regarding the correspondence between supplier's effort and resulting forging size, we assess the implications of two innovative approaches for improving supply chain performance: (i) input material reduction incentives via contracting and (ii) scrap material recycling. We characterize the optimal decisions with respect to final component geometry, various costs, and which party in the supply chain controls the strategic recycling decision. We find that the supply chain should utilize both approaches in a complementary way for components with complex geometry, yet deliberately limit recycling and eliminate contracting for components with simple geometry—a strategy the buyer always implements when controlling the recycling decision. Furthermore, we show these contracting and recycling strategies to be robust by considering linear, expected cost sharing, and nonlinear contract alternatives. Finally, we study supply chain inefficiencies that result from decentralizing the recycling and/or contracting decisions, and highlight whether expected cost sharing and nonlinear contracts can outperform linear contracts.

Green hydrogen production by water splitting using scrap metals at high temperature

Currently green hydrogen production is attracting global attention. In this context, sustainable hydrogen production processes have been explored by using variety of materials and methods. Generation of hydrogen without CO2 emissions is the key for carbon-free energy economy in future. Enormous amounts of scrap iron, metallurgical wastes and ferrous metals are produced in industrial processes. In this work, the reaction between metal scrap and steam is studied for hydrogen production. The scrap materials are loaded in a packed-bed reactor to produce green hydrogen by water splitting at high temperatures. This method produced 500 mL of green H2 per gram of scrap material at 1150 °C with a conversion efficiency of about 94%. This is a potential method to utilize the scrap metals for large scale production of green hydrogen without carbon emissions.

Mechanical behavior of recycled carbon fiber epoxy and vinylester composites produced by resin infusion with flexible tooling technology (RIFT)

This research aims to define a technological process to design and manufacture high-performance components with innovative composite materials and to assess a line of recycling and recovery of processing waste. The material under study is a felt (non-woven fabric) of short carbon fibres produced by recycling composite material scraps. The activities focus on determining the most suitable production processes and the related process parameters that best lend themselves the uses of recycled carbon felt. Thus, two different laminates were manufactured, adopting epoxy and vinylester resinand the same recycled carbon withthe same stacking sequence. Consequently, the same thickness was obtained,andthe process feasibility and its limits were determined. In addition, the quasi-static and FIMEC tests were conducted to investigate their behaviour under tensile and flexural loading, respectively, and highlight theinfluence of the different matrices used. The results revealed the perfectly elastic behaviour of the material, the strong anisotropy for the epoxy sample and a significant difference in mechanical response in terms of strength and modulus

Laboratory evaluation of properties of modified asphalt binder with different types of additives

This research aims to assess the properties of Polymer Modified Bitumen (PMB) binder prepared with different types of additives such as (Waste low density polyethylene (W-LDPE) and crumb rubbers (CR)and Styrene Butadiene Styrene (SBS)). Most of these additives are sustainable materials since it is derived from old scrap materials. All the above-mentioned materials (W-LDPE, CR and SBS) were added with percentages of (2, 4, and 6 percentage) of the weight of pure asphalt binder. Several tests were conducted to evaluated the properties of improved asphalt binder such as penetration test, Ductility test, Softening point test, Rotational viscosity test as well as thin-film oven test. The results of investigation revealed that, the using of different types of PMB significantly improved the physical properties and performance of asphalt. The using of sustainable waste materials such as W-LDPE and CR significantly improve the properties of PMB and contribute in recycling great amount of waste materials. Also, the results showed that the using of high percentage of SBS (6%) significantly increase the viscosity of asphalt binder and that can affect workability of Hot Mix Asphalt (HMA) compared with same percentages of W-LDPE and CR).

Thermochemical production of green hydrogen using ferrous scrap materials

Thermochemical water splitting is one of the methods to produce green hydrogen. In this study, metal scrap is used to split water by thermochemical process in a packed-bed reactor. Hydrogen production conditions are optimized by varying the particle size of the metal wastes in the range of 250 μm to greater than 1000 μm and the temperatures from 900 °C to 1200 °C. The maximum yield of hydrogen obtained is ∼500 mL of H2 per gram of the scrap sample. This study demonstrates that the discarded metal wastes can be utilized as feed-materials for thermochemical production of green hydrogen. The process has good conversion efficiency and is a promising solution for both metal waste management and the production of green hydrogen. Medium size metal particles show higher hydrogen production capacity compared to both smaller (<250 μm) and larger (600–1180 μm) size particles.

Resource‐efficiency actions and financial performance: Exploring the moderating role of production cost

AbstractThis study employs the Porter hypothesis framework to test the moderating role of production cost in the relationship between resource‐efficiency actions and financial performance for German small and medium‐sized enterprises (SMEs). For this purpose, we employ the 2012, 2018, and 2021 Flash Eurobarometer surveys to analyze how consistently SMEs adopt resource‐efficiency actions, and the impact of these actions on their performance and costs. We also conduct a generalized method of moments regression analysis (GMM). Among the seven resource‐efficiency actions proposed, saving water had a significant positive (negative) influence on financial performance in 2012, 2021, and (2018). Saving energy and using renewable energy had a positive and significant (insignificant) effect on financial performance in 2018, 2021, and (2012). Finally, selling scrap material to other companies had a positive and significant impact in all years. Furthermore, increased production costs negatively moderate the relationship between eco‐efficiency action scores and financial performance. The results indicate that the “strong” version of the Porter hypothesis is not supported: It only holds when the implementation of eco‐efficiency actions reduces production costs and increases financial performance.

Microstructure and mechanical properties of two novel scrap tolerant Al65Cu10Mg10Si10Zn5 and Al80Cu5Mg5Si5Zn5 high entropy aluminum alloys

The microstructure and mechanical properties of two novel Al65Cu10Mg10Si10Zn5 and Al80Cu5Mg5Si5Zn5 high entropy aluminum alloys were studied. The alloys were developed from predominantly scrap materials by high pressure die casting route. The microstructure of the alloys revealed a complex conglomerate of phases consisting of α-Al matrix reinforced with Al2Cu and Q-phase compounds. In terms of mechanical properties, the alloys exhibited low plastic deformation and high strength at room temperature, and increased plasticity up to 15.3% with high strength up to 317 MPa at 200 °C. The hardness value was in the range of 223 HV to 271 HV, which is three times higher than that of commercial Al alloys. The wear rate of Al65Cu10Mg10Si10Zn5 and Al80Cu5Mg5Si5Zn5 alloys was compared with that of a commercial AlSi9Cu3(Fe) and AlSi10MnMg alloys, proving the superior wear resistance of the developed alloys. Finally, the possible wear mechanisms for each alloy were proposed. Overall, the results suggest that these novel high entropy aluminum alloys have promising mechanical and wear properties, making them suitable for various industrial applications.

Assessing the thermal performance of upcycled shipping container as a sustainable building material in a Warm humid climate

The current trends in the construction sector are responsible for majority of the CO2 emissions in India. The sustainable methods to reduce the CO2 emissions should include not just recycling but also upcycling the materials, for instance – shipping containers. Despite the industry’s best efforts to minimize waste generation, millions of shipping containers end up as scrap materials, every year. This phenomenon can be changed effectively by reusing the scrap materials as alternate building materials. The trend of reusing the shipping containers as building materials is at its peak in Western countries, while in India, it is still in a nascent stage. The aim of the current research paper is to evaluate and assess the thermal performance of upcycled shipping containers as a building material in warm humid climatic condition. This research includes a review of literature about the strengths and weaknesses of the shipping containers as a building material; it also compares and evaluates the thermal performance of uninsulated container buildings with base case conventional building and the insulated container building through Opaque simulation method. The results were obtained by comparing and assessing the thermal performance and cost of various insulating materials for a container building. The study outcomes greatly help the architects to reuse the shipping containers as a sustainable alternative building material in warm humid regions.

Recycling Hazardous and Valuable Electrolyte in Spent Lithium-Ion Batteries: Urgency, Progress, Challenge, and Viable Approach.

Recycling spent lithium-ion batteries (LIBs) is becoming a hot global issue due to the huge amount of scrap, hazardous, and valuable materials associated with end-of-life LIBs. The electrolyte, accounting for 10-15 wt % of spent LIBs, is the most hazardous substance involved in recycling spent LIBs. Meanwhile, the valuable components, especially Li-based salts, make recycling economically beneficial. However, studies of electrolyte recycling still account for only a small fraction of the number of spent LIB recycling papers. On the other hand, many more studies about electrolyte recycling have been published in Chinese but are not well-known worldwide due to the limitations of language. To build a bridge between Chinese and Western academic achievements on electrolyte treatments, this Review first illustrates the urgency and importance of electrolyte recycling and analyzes the reason for its neglect. Then, we introduce the principles and processes of the electrolyte collection methods including mechanical processing, distillation and freezing, solvent extraction, and supercritical carbon dioxide. We also discuss electrolyte separation and regeneration with an emphasis on methods for recovering lithium salts. We discuss the advantages, disadvantages, and challenges of recycling processes. Moreover, we propose five viable approaches for industrialized applications to efficiently recycle electrolytes that combine different processing steps, ranging from mechanical processing with heat distillation to mechanochemistry and in situ catalysis, and to discharging and supercritical carbon dioxide extraction. We conclude with a discussion of future directions for electrolyte recycling. This Review will contribute to electrolyte recycling more efficiently, environmentally friendly, and economically.

Experimental investigation and two-factor factorial analysis of a solar air heater with scrap wire meshes and cans as energy storage components

This study investigates the performance of a solar air heater with scrap materials. No absorber sheet was included in the system, just scrap aluminum cans and wire meshes were used as its absorber to store and transfer solar energy to air. The arrangement of components inside the collector was varied and each configuration was tested with different air mass flow rates. Three different configurations included: vertically arranged cans, vertically arranged cans with meshes and horizontally arranged cans and their mean thermal efficiencies were found as 40.7 %, 45.8 % and 63.4 % at the highest airflow rate (0.043 kg/s m2), respectively. The highest performance (82.2 %) was obtained from the collector with horizontally arranged cans at the same mass flow rate. It was also found that the collector efficiency increases as rolled mesh layers added alongside cans. The pressure drop was considerably low (2 to 14 Pa) in all the setups. The two-factor factorial design method was used to evaluate the experimental data obtained in this study. The analysis showed that both factors (Collector arrangement and airflow rate) had significant effects on the thermal performance of the system.

Recovery of base and precious metals from scrap TV boards using zig-zag air separator

Waste of Electrical and Electronic Equipments (WEEE) is one of the fastest growing waste streams in the world. The treatment of WEEE with high content of precious metals (Au in particular) has received the most attention due to their high economic potential. The development of simple, environmentally friendly and cost-effective methods for the recovery of metals from “low-value” WEEE (e.g., &lt;100 g/t Au) is important from the circular economy perspective. In this study, the separation of base (Cu) and precious (Ag) metals from scrap TV boards (STVBs) by using a zig-zag air separator was investigated. Size-reduced scrap STVBs (-1 mm) were subjected to separation tests after the removal of the fine fraction (-0.1 mm). The sized scrap material (-1 +0.1 mm) was determined to have a metal content of 15.4% Cu, 47 g/t Ag and 0.05% Fe, with no gold. In the air separation tests, the effect of air flow rate (4-16 m/s) on the recovery of metals was studied. Increasing the air flow rate resulted in low metal recoveries with concurrent high metal grades in the concentrate. Separation efficiency (%) calculations showed that the most efficient separation is obtained at the highest air flow rate of 16 m/s. At this flow rate, 15.4% of the material was recovered in the concentrate which contains 62.3% Cu and 198 g/t Ag with recoveries of 63.3% Cu and 73.9% Ag. The findings indicated that zig-zag air separators can be used to obtain a metal-rich fraction under suitable conditions of the flow regime.

Analisis Sifat Mekanik Pada Material Standar Paduan COR ALSi10Mg(b) Dari Skrap Aluminium

The metal industry in Tegal Regency is classified into ferrous and non-ferrous metal industries. The shipping component industry is the leading producer of the non-ferrous metal industry. The problem faced by the non-ferrous metal processing industry, especially the Small and Medium Industry ship components is the availability of standard materials as raw materials at affordable prices. Instead, SMEs use scrap material to reduce selling prices, as a result of which product quality does not meet the required specifications. This research made 2 (two) formulas of AlSi10Mg(b) from an aluminum scrap mixture where AlSi10Mg(b) is one of the standard materials of cast aluminum alloy recognized by Biro Klasifikasi Indonesia (BKI). The study aimed to recommend raw material formulas to SMEs to ship components to make products according to BKI standards. The research began by collecting a database of aluminum scrap composition, then simulating calculations with an Excel program to obtain theoretical chemical composition so that the need for aluminum scrap was produced. The two standard material formulas of AlSi10Mg(b) are made from different main scrap where formula 1 is the piston, and formula 2 is the brake lining with the supporting scrap is the pan, aluminum elbow, and aluminum plate as well as the AlSi49 and AlMg20 master alloys. The simulation results are then cast with the sand-casting method. The cast results are made of specimens testing chemical composition and hardness. The results of the chemical composition test show that both formulas are in accordance with the conditions of AlSi10Mg(b) cast alloy, namely the percentage of Silicon (Si) and Magnesium (Mg) in formula 1 is 9.16% and 0.39% while formula 2 is 10.69% and 0.22%. Both formulas are still with Copper (Cu) content that still exceeds the limit of above 0.1%. The hardness value has met BKI standards above 50HBN.

Recycling of waste aluminum/magnesium metal scrap into useful Al‐ZrO2 alloy composite for eco‐friendly structural applications

AbstractFabrication industries are emerging to reduce and recycle waste scrap materials into useful products for various engineering applications such as domestic, structural, marine, and construction doors and windows. Most waste scrap materials are affected by soil and water pollution, resulting in unsuitable environmental living. This study is to fabricate the low‐cost and eco‐friendly Al‐ZrO2 alloy composite made with waste Al/Mg metal scrap microparticles through stir casting technique and the developed composite with 0 wt%, 5 wt%, 10 wt%, and 15 wt% of ZrO2 were studied its mechanical properties (ASTM). The synthesized composites' mechanical tensile strength, impact, and hardness were evaluated by ASTM test standard. The revealed experimental results were compared and an optimum sample was addressed. The optical micrograph studies revealed the metal particle presence. The sample 4 composite contained 15 wt% of ZrO2 particles and showed superior mechanical properties like 7.7%, 57.7%, and 13.66% improvement in tensile strength, impact toughness, and hardness compared to sample 1 without ZrO2 particles.

Carbon Sequestration in Lumber Columns: Facilitating the Reuse of Lumber Waste for Prefabrication through Computational Design and Augmented Fabrication

Industrial prefabrication brings benefits such as higher productivity and reduced waste production. However, waste, cut-offs, and failures cannot be prevented even in a prefabrication setting. Yet, most processes for utilizing scrap materials promote downgrading. This research presents a construction framework to facilitate the reuse and salvaging of lumber waste from a lumber construction company using a computational design (CD) and augmented reality (AR) setup. Specifically, we explore the design of columns based on an inventory of scrap materials and propose a high level of automation (LoA) prefabrication for reusing lumber waste for structural parts. The design and AR framework support the extension of the matching skillset through the integration of existing materials and the automation of creating an assembly plan for AR, improving the reusability of cut-off lumber blocks. It features a design tool for placing existing lumber scrap blocks and an integrated AR application for assembling these blocks into wood columns. The setup is demonstrated through column prototypes, resulting in six columns, each 10 feet high. The proposed methods extend the opportunities for designers to reuse lumber scraps for prefabrication and simplify assembly instructions for craftspeople, providing valuable tools to enable a resource-efficient workflow for lumber scrap.

Hot Forging Die Design Optimization Using FEM Analysis for Near-Net Forming of 18CrNiMo7-6 Steel Pinion Shaft

The objective of the presented work was to develop a new forging process for a pinion shaft as a component of a wind turbine. A study of near-net-shape forming using Deform 3D software was performed to reduce operational cost, time, and material scrap; enhance specific properties; increase productivity. Near-net forged products have good dimensional accuracy and continuous metal flow lines, which are characteristic of improved mechanical properties. To avoid the traditional trial-and-error experimental method, the process and tool design were accomplished with a careful and detailed numerical simulation approach. In the present work, the Finite Element Method was used to develop a process model for the existing hot forging process of the 18CrNiMo7-6 steel pinion shaft used in a wind turbine. The developed numerical process model was validated via experiment including a comparison of the metal flow lines from the FEM model with the metallography results of the forged part. Two new die designs were proposed, and the simulation results were compared to the actual process to achieve improved geometry. The results for the new geometries showed improvements in terms of the die cavity filling for the new proposed dies and better results in grain flow orientation. Compared to the initial non-optimized die, the new designs improved the mechanical properties and savings associated with the lower volume of required raw material and fewer finishing operations. Considering the applied stresses and wear in the new near-net shape, the die geometry shall be updated to accommodate more severe solicitations. Naturally, all the improvements carried out are dependent on other factors such as the conditions of the equipment, operator skills, lubrication, and other variables. A surface heat treatment is also suggested for stress relief as a reliability improvement.

Development and implementation of a significantly low-cost 3D bioprinter using recycled scrap material.

The field of 3D bioengineering proposes to effectively contribute to the manufacture of artificial multicellular organ/tissues and the understanding of complex cellular mechanisms. In this regard, 3D cell cultures comprise a promising bioengineering possibility for the alternative treatment of organ function loss, potentially improving patient life expectancies. Patients with end-stage disease, for example, could benefit from treatment until organ transplantation or even undergo organ function restoration. Currently, 3D bioprinters can produce tissues such as trachea cartilage or artificial skin. Most low-cost 3D bioprinters are built from fused deposition modeling 3D printer frames modified for the deposition of biologically compatible material, ranging between $13.000,00 and $300.000,00. Furthermore, the cost of consumables should also be considered as they, can range from $3,85 and $100.000,00 per gram, making biomaterials expensive, hindering bioprinting access. In this context, our report describes the first prototype of a significantly low-cost 3D bioprinter built from recycled scrap metal and off-the-shelf electronics. We demonstrate the functionalized process and methodology proof of concept and aim to test it in different biological tissue scaffolds in the future, using affordable materials and open-source methodologies, thus democratizing the state of the art of this technology.

Li-Cycle to recycle batteries in France

The lithium-ion battery recycling company Li-Cycle plans to build a facility in France capable of processing 10,000 metric tons of battery materials per year starting in 2024. The plant will recycle batteries from the Kion Group, which provides forklifts and other vehicles to warehouses. Li-Cycle says the facility could also recycle scrap material from three battery factories planned nearby. Li-Cycle says it’s on track to be the largest dedicated lithium battery recycler in Europe and North America.

3D Printing Smart Eyeglass Frames: A Review

Eyeglasses are typical correctors for refractive error eye disorders. They are commonly placed on frames expected to be stylish and durable. Currently, the consumer demand for sustainable and eco-friendly frames is gaining interest, especially since conventional frame manufacturing methods follow a subtraction of large blocks of wasted scrap material. Additive manufacturing (AM) promises better economic feasibility due to reduced tooling, storage, and material costs, as well as enhanced mechanical properties, by inducing nanomaterials and composites. Moreover, synergism between AM and digital design has led to a rising interest in smart or electronic eyeglass frames. This systematic review assesses commercial eyeglass frames that use standard materials with long-lasting resistance, durability, comfort, and versatility with various materials such as metals and polymers. It also explores the design aspects of these eyeglasses and their correlation with the utilization of artificial intelligence trained computer-aided design software. Beyond the appealing eyeglass frame technology, a review of smart frame design, in which electronic sensors and chips are embedded, is also included. Furthermore, this review comprises various applications for 3D printing of frames including commercial and biomedical applications. Other reviewed topics include the side effects, health risks, shortcomings of AM techniques and materials, and void formation inside the matrix that propagates fatigue and shrinkage or density change during solidification.

The Flip-flop Toys of Saarenald T. S. Yaawaisan in the Bryn Mawr Art and Artifact Collections

The Flip-flop Toys of Saarenald T. S. Yaawaisan in the Bryn Mawr Art and Artifact Collections