Foundry Industry Research Articles

A Review on Automotive Industries and Foundries in Nigeria

The Federal Government of Nigeria has taken different precautions to support domestic vehicle assembly industries as part of the Nigeria Industrial Revolution Plan (NIRP) to diversify the economy from oil and gas sector to other sectors. The potentials of foundry industries in Africa and most especially in West-Africa Sub-region are under-utilized unlike in the developed countries. Most of the Foundries in Nigeria are operated by Small Scale Industries (SMI) and are not being able to contribute significantly to the automotive industries in the country. This paper is aimed to review several works done by different researchers in the automotive and foundry industries with the view to study the contribution of foundries in the development of automotive industries in Nigeria.

Recovering Aluminium for Recycling in Reusable Backyard Foundry that Melts Aluminium Cans

In a world which is increasingly demanding sustainability, nonferrous metal recycling has become a very important practice. Millions of tons of nonferrous scrap are recovered annually and used by smelters, refiners, ingot makers, foundries, and other manufacturers. Secondary materials are essential to the industry’s survival because even new metals often require the combined use of recycled materials. The recovered materials are melted down in a furnace, poured into casters and shaped into ingots. These ingots are either used in the foundry industry or they can be transformed into flat sheets and other wrought products, which are then used to manufacture new products. Aluminium offers intelligent and practical solutions to recovering for recycling. The main activities described in this article are carried out during the experimental phase of the research and they are oriented towards the recovering aluminium for recycling. The objective of the research is to develop some recycling facilities for re–smelt and re–cast of aluminium by using charcoal briquettes into a mini metal foundry, designed and manufactured in laboratory. In this research we experimented a reusable backyard foundry that melts aluminium cans (soda and beer) easily and safely.

Reconstructing a Five Mould Semi-Centrifugal Casting Machine for the Local Foundry Industry in Ghana

Most cast objects produced by the Ghanaian local foundries are of low quality, and it is because they utilize the wrong method of casting (mould feeding). The local foundries were looked into to find out the casting techniques they employed, and centrifugal casting machines were investigated to be able to come up with a design that best suited the operations of the local foundries to improve their work- and a miniature of it was fabricated. Qualitative research design (descriptive, studio based, and experimental) was used to collect data from a sample size of 70 foundry men from an accessible population of 180 professional foundry men. It was found that the local foundries limit themselves to sand casting and cuttlefish bone casting, but most foundry workers are willing to learn and apply any new technique to improve their productivity. Also, gravitational mould feeding mostly produces casts with poor surface quality, and because mass production is done manually and hurriedly, the foundries end up discarding and reproducing most casts. It is recommended that the local foundries should employ centrifugal casting techniques as practiced in this research to improve their production and services. Also, centrifugal casting, which uses centrifugal force is an ideal way of mould feeding in the foundries and must be utilized in the foundries to improve product quality, and multiple mould-feeding centrifugal casting machines as fabricated in this study should be employed by the local foundries to improve the effectiveness of their mass productions. It is also recommended that the local foundries must form a more organized and structured association with delegated tasks and functions in order to get the attention of the government for aid, should the need be.

Analysis of Heating System in FBC of Sand Reclaimer

In recent years, the foundry sector has been showing an increased interest in reclamation of used sands. Grain shape, sieve analysis, chemical and thermal characteristics must be uniform while molding the sand for better casting characteristics. The problem that tackled by every foundry industry is that of processing an adequate supply of sand which has the properties to meet many requirements imposed upon while molding and core making. Recently, fluidized bed combustors are becoming core of ‘clean wastes technology’ due to their efficient and clean burning of sand. For proven energy efficient sand reclamation processing, analysis of heating system in fluidized bed combustor (FBC) is required. The objective of current study is to design heating element and analysis of heating system by calculation of heat losses and thermal analysis offluidized bed combustorfor improving efficiency.

Properties of silica sand and GBF slag moulds practiced by Nishiyama process

ABSTRACTInvestigations were carried out to use Granulated Blast furnace (GBF) slag as mould material for either full or partial replacement of existing silica sand in foundry industry. Nishiyama process was adopted for evaluating the same. A series of sand tests were carried out on sand and slag individually and also combinations of these two. Three types of moulds were made with sand, slag individually and combination of these two. Both laboratory and industrial castings of ferrous and non ferrous materials were performed. Results of mould permeability, compression and shear strength of GBF slag reveal that is a suitable candidate for either partial or full replacement of molding sand. During casting of both laboratory and industrial, neither fuse, dripping nor collapse of the mould walls was observed; this is true for both ferrous and non ferrous castings. Castings with good surface finish, no surface defects and porosity were made by slag moulds.

Research on the influence of furan resin addition on the performance and accuracy of 3D printing sand mold

Aiming at the problem of performance and dimensional accuracy instability of casting sand mold under immature process, a study on the influence of different content of furan resin on the performance and dimensional accuracy of casting 3D sand mold was carried out. With the same tensile test block, compression test block and standard size measurement test block printing process as experimental conditions, based on industrial grade 3D printing equipment, the changing rule of parameter change of furan resin added is studied. On this basis, a variety of different resins are used to print the test block, each group takes the same number of test blocks. Mechanical properties and dimensional accuracy were measured. The influence of resin addition on product performance and dimensional accuracy was studied by range analysis. The experimental results show that there is a relationship between the interaction and dependence between the numerical addition and the mechanical and dimensional precision of the 3D print sand mold. The mechanical and dimensional precision of the sand mold can be reached to the best level in a certain range of resin added. The research results provide guidance and direction for further promoting the application of 3D printing technology in the foundry industry, and provide a theoretical basis for the application of 3D printing sand in different casting situations.

Research on the method for improving mechanical properties of sand mold based on 3D printing process

Aiming at the problem of strength instability of casting sand mold under immature process, a study on the strength influence factors and the method for improving the performance of casting sand mold. With the same typical casting sand mold printing process as the experimental conditions, the comparison experiments were carried out from the change of the 3D printing process parameters, the increase of the mechanical vibration to increase the sand density and the introduction of the heat source to speed the sand mold curing speed, The influence of the above methods on the strength of printing sand mold is analyzed. Comparative experimental research shows that the test methods have effectively improved the strength of the sand mold, and the combination of that three methods has a better effect. The research results provide guidance and direction for further promoting the application of 3D printing technology in the foundry industry, and provide a theoretical basis for the application of 3D printing sand in different casting situations.

New Possibilities with Improved Green Sand Testing Equipment

The quality of green sand moulds is paramount for the casting quality and reduction of surface defects. The general knowledge within foundries on green sand properties and its influence on casting defect behaviour has significantly decreased as a result of outsourced external sand testing and dependence on external consultants. Moreover, academic R&D activities targeting studies on green sand properties could not attract significant funding and have hence been limited to small extents. It cannot be stressed enough that in sand casting the majority of casting defects can be related to an insufficient green sand management. Recent research and development has been only supported by suppliers of the foundry industry, however, with a major emphasis on anorganic water glass binder systems and the reduction of phenolic binders in organic binders to reduce emission and unpleasant smells while simultaneously increasing e.g. fluidity or strength. In most industrial environments hand-operated sand testing machines, whose basic concepts of operation were developed in the middle of the last century, are still used. While these old fashioned apparatuses can help to maintain quality in a foundry they are not suited to provide additional information on the green sand quality. Therefore, any developments on different mould materials were mainly performed with very old fashioned manually operated sand testing equipment and a significant aspect of the development of more accurate modern sand testing equipment was neglected. Nevertheless, these manually operated sand testing apparatuses represent the current state-of-the-art of sand testing equipment. In order to improve green sand properties and gain additional knowledge it is essential to develop new testing methods. This paper will give information on the development of novel green sand testing equipment for compaction, pressure, as well as wet strength testing development at the ÖGI and gives comparison to values obtained by manually operated machines. The main advantage of modern electronical testing machines is a higher accuracy of measurement in general and the possibility of recording stress-strain-curves. This work shows characteristic stress-strain-curves for all mechanical green sand testing methods as well as the influence of water content on the progression of mechanical properties. As a result the area with the best handling properties of green sand is shown. Furthermore negative influences of defective sand specimens and marginal deviations in the testing process on the testing result have been investigated.

Design methodology for variable shell mould thickness and thermal conductivity additively manufactured

Additive manufacturing (AM) is said to be the fourth industrial revolution disrupting the manufacturing industry. A focus on the foundry industry’s need, more specifically the sand casting process, is done. The usage of additive manufacturing in this field necessitates a different mould design approach. Indeed, it is important to take advantage of AM and the advantages of casting. The fabrication methodology of the mould is binder jetting technique. The almost limitless design possibilities of additive manufacturing are applied to sand moulds for metal casting. A new methodology to optimise the design of sand moulds is proposed. This optimisation reduces the amount of sand to the minimal need, which corresponds to a shell. The shell is then parametrised to have a specific cooling rate. In this case, the cooling speed can vary via a modification of the coefficient of thermal conductivity and shell thickness. The cooling speed is correlated to the dendrite arm spacing, which determines the mechanical properties such as ultimate tensile strength and hardness. Simulations of the cooling support the mould design methodology.

Probabilistic risk-based pollution prevention model for a foundry: a case study of casting.

Hazardous air pollutants from industrial activities have long been associated with serious health effects. Traditional health risk assessment uses point estimates of inhalation concentrations based on standard Gaussian diffusion models with steady-state emission rate assumptions. This traditional approach was criticized because it does not account for variability and thus leading to a potential overestimate of the health risk from the batch processes. To overcome this deficiency, a probabilistic risk assessment model is proposed. The foundry industry with processes typically associated with several hazardous air pollutants is identified and iron casting is chosen as a case study to compare risk estimates. Existing data, representing historical proprietary information of the case study, were used to deliver representative risk values and help identify potential replacements or interventions in the manufacturing process. A probability distribution function of emitted concentrations was simulated to model the batch process emissions from mold and core resin binders, a major source of pollution. The same method was applied to exposure factors to feed into the risk model resulting in a probabilistic risk evaluation. Several alternative resin binders in commercial use were examined to offer a risk-based substitute to the resin binder in use. The risk results provided an opportunity to consider newer and environmentally friendlier options. A comparison of the resultsfrom this approach and those from the point estimate analysis reveals a gross over estimation of risks. The point estimate risk values were about eight time larger than the mean value and about twice the 95th percentile values of the probabilistic risk approach. The wide range of variability among resin binders associated risk results, close to two orders of magnitude in some cases, presented opportunities to select from a variety of binders with lesser emissions and lower risk. Optimal selection will depend on several pollutants emitted from this process to help address cumulative impacts of multiple pollutants. Investigations are underway for a multi-pollutant strategy including trade-offs, and other quality controls vital to the decision-making.

In-plant production of bricks containing waste foundry sand—A study with Belgaum foundry industry

The main objective of this study is to utilize waste foundry sand (WFS) from Belgaum foundry industry in manufacturing of bricks. The process involved production of bricks in a fully functioning brick manufacturing plant, which has a production capacity of approximately 50000 bricks per month. The entire process of combining clay-sand mixtures, forming of bricks, drying and firing was done with local conditions. With minimum process it was possible to introduce upto 50% WFS in clay bodies to produce bricks of desirable properties. The minimum average wet compression resistance of 3.3 Mpa, and maximum average water absorption of 21.6% was obtained for bricks containing 50% WFS, when fired at 900 °C. There was insignificant difference in apparent porosity, water absorption, and specific gravity of bricks containing WFS, when compared to commercial bricks. The addition of WFS reduced the bulk density of the bricks, which has also caused reduction in compressive strength. WFS bricks can be classified as class III bricks, based on recommendations of IS 1077 standard specification. These bricks can be used in single storied load bearing structures, and also in the construction of infill walls in multi-storied framed structures. The structure, composition, and morphology of the raw materials, as well as bricks were studied by XRD, XPS, and SEM, respectively.

Modeling of an aluminum melting process using constructive polynomial functions

Constantly increasing quality requirements and ever-stricter conditions pose difficult challenges for the foundry industry. They must produce the high-quality components demanded by the market at a reasonable cost. Modern technologies and innovative methods help to master this challenge. Until recently, production, from the design of the aluminum melting furnace to daily process, relied largely on traditional methods and experience. However, important data and information about the melting process—for example, the temperatures and the shape of the aluminum block in the furnace—can hardly be obtained with conventional experimental methods, as the temperatures exceed 700 °C. Therefore, this research project investigates the method of monitoring a melting process by means of optical sensors for the first time. The purpose of this paper is to predict the surface shape of the block during the melting process, as it is not possible to maintain a constant monitoring due to the heat and energy loss during measurement Behrens (Einsatz einer Lichtfeldkamera im Hochtemperaturbereich beim Schmelzvorgang von Aluminium, wt Werkstattstechnik online, 2016). To generate the necessary data, a 3D light-field camera is installed on top of an aluminum melting furnace in order to monitor the process. The basic idea is to find a general method for curve modeling from scattered range data on the aluminum surface in 3D space. By means of the (x, y, z) data from the 3D camera, the aluminum surface is modeled as a polynomial function with coefficient derived using various interpolation and approximation methods. This study presents an attempt to find the optimal polynomial function model that describes the aluminum surface during the melting process by interpolation or approximation methods. The best method for curve fitting will be extended and implemented for surface modeling. Based on this method, the melting process can be better controlled while the furnace operates continuously under stable conditions and the efficiency can therefore be increased. The proposed model can be modified for a wide variety of melting furnaces.

Numerical Simulation of Induction Channel Furnace to Investigate Efficiency for low Frequencies

The foundry industry worldwide commonly uses induction channel furnaces to heat and melt alloys. The operating frequency is one of the main issues when constructing an efficient channel furnace. It is possible to choose operating frequencies lower than 50 Hz using a modern IGBT power converter. This work shows the simulation results using ANSYS with the goal of finding the best electrical frequency necessary to operate the induction furnace. First, a two-dimensional model is used to calculate the efficiency depending on frequency. Then, the channel model is extended to a more realistic three-dimensional model. Finally, the influence of frequency, inductor profile, and several components of the induction channel furnace are discussed.

MODERN EQUIPMENT FOR REFINING AND CASTING OF STEEL AND ALLOYS IN FOUNDRY PRODUCTION

The article deals with the issues of complex technology and equipment for refining and casting steel and alloys in the foundry industry. Solutions are given that make it possible to guarantee a reduction in nonmetallic inclusions in the melt, as well as to solve a number of other related problems of foundry production, such as the introduction of a bottom blowing melt system with an inert gas; the introduction of protection of the metal stream from secondary oxidation; lining the arch of an electric arc furnace, etc. Various types of products and equipment produced by NPP Vulkan-TM are shown: blowing bottom plugs and assemblies, metering nozzles, gas-dynamic protection of the metal stream from secondary oxidation, two-arm wire-feeding machine mod. TAP 2–1 with unwinding device.Advantages of the equipment for steel casting and extra-furnace steel processing are described.

A variable neighborhood search for multi-family capacitated lot-sizing problem

The paper presents a novel variable neighborhood search (VNS) algorithm combined with a linear programming solver (LPS) to solve multi-item multi-family capacitated lot-sizing problem with setup times independent of the family sequence. The model has a direct application to real production planning in foundry industry, where the goal is to create the batches of manufactured castings and the sequence of the melted metal loads to prevent delays in delivery of goods to customers. We developed a simple and fast VNS based algorithm with problem-specific operators that are responsible for the neighborhood generating. For large instances of the problem the proposed algorithm is able to provide better results than CPLEX solver.

PAH exposure-associated lung cancer: an updated meta-analysis.

Occupational exposure to polycyclic aromatic hydrocarbons (PAHs) has been shown to be associated with lung cancer in various epidemiological studies in industries such as aluminium reduction/smelting, coal gasification, coke production, iron/steel foundries, coal/coke and related products and carbon/graphite electrodes production. To update data on the association between PAH exposure and morbidity and mortality due to lung cancer among workers in different occupations, including smoking data. A comprehensive literature search was conducted to retrieve relevant papers for meta-analysis. Cohort studies with standardized mortality ratios or standardized incidence ratios and calculated overall risk ratio with their corresponding 95% confidence intervals (CIs) were included in the analysis. Chi-square test for heterogeneity was used to evaluate the consistency of findings between the studies. A significant risk of lung cancer was observed among the coal/coke and related product industry 1.55 (95% CI 1.01-2.37) and the iron/steel foundry industry 1.52 (95% CI 1.05-2.20). There was a wide variation in smoking habits and PAHs exposure among studies. Coal/coke industry and iron/steel industry workers showed a higher risk of lung cancer compared with other occupations exposed to PAHs. The confounding effects of smoking and individual exposure levels of PAH should be taken into account.

Granulated blast furnace slag – A boon for foundry industry

In the present investigation efforts have been put together to employ Granulated Blast furnace (GBF) slag as mould material for replacement of existing silica sand either full or partial in foundry industry. Nishiyama procedure was assumed for appraising the same. The process factors reflected on for this were the % of sodium silicate, % of Fe-Si powder and mould setting time. A sequence of tests on sand was conducted on sand, slag as per American foundry society standards. Two categories of moulds were built by means of sand and slag independently with optimum process parameters. A356 alloy and grey cast iron castings were executed on these recently built up slag moulds. The outcomes show that the mould’s compression, permeability as well as the shear strength of the GBF slag is an appropriate candidate for either incomplete or complete substitute of moulding sand. At some point in casting, the absence of fusing, dripping or mould wall collapse walls was noticed; this is exact for the ferrous as well as non-ferrous castings. Castings exhibiting high-quality surface finish, absence of surface defects as well as porosity were created by slag moulds.Keywords: Silica sand; Blast Furnace Slag; Mould properties; Ferrous and nonferrous castings.

Reclamation of used green sand in small scale foundries

Disposal of Used Foundry Green Sand (UFGS) remains one of the significant challenges faced by foundry industry nowadays. Experiments were performed to reduce the total clay content from 12% to as low as 2.2% in waste foundry sand. Three prototypes were developed during the course of this work. They include vertical fluidized bed, horizontal fluidized bed and a novel ball-mill type attrition and sieving unit. The cost per ton of reclaimed sand is higher in case of fluidized bed based prototypes while in case of attrition and sieving based prototype, it is less than half of the cost of the fresh sand. The experimental data generated on the two-stage attrition and sieving unit under different conditions is further used to arrive at a semi-empirical correlation and the optimum set of design and operating parameters to get the best performance.

Computer simulation of railway wagon brake disc casting

CAD systems serving as the model for real industrial processes are almost an inseparable part of manufacturing in many industry branches. The use of simulation programs in the foundry industry is perceived as a tool for the visualization of the processes involved in the production of castings. They are also used to resolve possible issues and imperfections before the production begins. Consequently, it enhances the quality and reduces product-manufacturing-related financial costs. The paper tackles the issue of how to resolve the occurrence of defects – shrinkages in the railway wagon disc casting while using a simulation program. The 3D model of the casting and of the system of gates was constructed in the CATIA CAD system. The mere simulation of the casting and solidification process was done in the NovaFlow&Solid program. After evaluating the results of the simulation, the correction of the casting and gates was made in order at once to enhance the quality of the casting and reduce the production costs in the manufacturing of this casting. In the production of the brake disk casting, the main issues are little usage of molten metal during casting and the considerable occurrence of shrinkages, which causes the increased economic costs of its production.

New Plant-Technologies for Reducing Carbon Emissions and Costs in Heat Treatment Processes of Aluminium Castings

The sustainable usage of our precious energy resources is one of the most challenging topics in current developments in the field of mechanical engineering. Apart from the use of a product, the requirements for reducing the impact of manufacturing activities are also increasing, not least because of their economic relevance. Energy-intensive processes, such as foundry industries, are particularly affected. In Aluminium foundries, in addition to the melting process and primary shaping, heat treatment is also of particular significance for an eco-oriented redesign of thermal processing operations. In consideration of the efficient use of energy-resources, this study focuses on the development of innovative plant technology for a sustainable heat treatment of aluminium components. In contrast to previously known solutions, the developed gas-heated furnaces (based on a newly designed burner system) can provide the necessary processing heat for the first time in an electrical control quality. Additionally, the control of the developed burner allows for the reliable utilization of hot air, and thus the effective reuse of waste heat. Conducted analyses and verifications of the prototype plant exhibit tremendous potential for reducing the energy consumption, for lowering costs (savings up to 70%) and CO2 emissions (reduction of 60%), without adversely affecting the quality of the components.