Metal Casting Process Research Articles

Evaluation of Physical, Performance and Emission Characteristics of Green Sand

For many years, researchers in the foundry industry and universities have been developing testing protocols to evaluate the physical, performance and emission characteristics of prepared green sand during pouring, cooling and shakeout. This paper will review the testing protocol and methods utilized in the collection and evaluation of these characteristics that is the result of the entire metal casting process. An important criterion also is the quality of the green sand mold and casting produced (defect free) when the emission characteristics are reduced. This paper will also include the laser imaging evaluation of the castings that is the result of the green sand foundry emissions.

Computer evaluation of the influence of liquid metal movements on defects formation in the casting

This paper concerns the modelling of the solidification process including the phenomena of heat transfer and fluid flow during the initial stage of the metal casting process. During this period, the molten metal motions have an essential influence on solidification kinetics. An analysis of solidification kinetics, by determining the velocity and temperature fields in a system of riser-casting was made. Velocity fields were obtained by solving the momentum equations and the continuity equation, while the thermal fields were obtained by solving the conduction equation containing the convection term. After completion of the filling process the main solidification of molten metal takes place and its shrinkage. The phenomenon of casting shrinkage cannot be avoided, but it is possible to minimize its negative effects on the casting quality. One with ways to solve this problem is to design the mould in such a way that the solidification proceeds in accordance to the assumed direction and finished in the riser. Generally, the aim of search is to obtain a casting without shrinkage defects.

Analysis of Hardness, Microstructure, Macrostructure, and Fluidity of Al-Si with Eggshell Variation as Binder in Sand Casting

Metal casting process can be described as the process of making object by melting metal then poured into the desired mould. The mould that is commonly used is sand moulding. Binder which commonly used in sand casting process is bentonite. Bentonite is kind of mineral which can be run out if it is used continuously. The background of this study was to analyse the other binder that could reduce the use of bentonite by utilizing eggshell. This study aimed to analyse the hardness, microstructure, macrostructure, and fluidity of the cast which yielded by using variations of eggshell. The method that used was experimental method with a model of one-shot case study with descriptive analysis. The study result showed that the highest value of fluidity test was found at variation of 7% eggshell and 3% bentonite with hardness value of 180.86 HV. There were found several defects, casting result with variation of 4% eggshell and 3% bentonite found that there were ± 28 pinhole defects and ± 20 open grain defects. There were found ± 65 pinhole defects and ± 30 open grain structure defects in the casting result with variation 7% eggshell and 3% bentonite. The casting result with variation 10% eggshell and 3% bentonite had ± 50 pinhole defects and ± 30 open grain structure defects.

Analysis of Mechanical Properties and Permeability of Sand Moulding by Using Eggshell in Sand Casting

This study aimed to analyse the usage of Eggshell as mixture material of bentonite in metal casting process which used dried sand moulding. Eggshell variations in this study were 4%, 7%, 10% eggshell, and additional 3% of bentonite on each sample. This study used pre-experimental method and included to One-Shot Case Study model. The highest strength was found on the sample 3 ES 10%. Tensile strength of dried sand moulding reach up to 0.09 kg/cm 2 , the compressive strength of dried sand moulding reached up to 3.11 kg/cm 2 , and the shear strength of dried sand moulding reached up to 1.13 kg/cm 2 . Based on the test result indicated that permeability of sand moulding by heat treatment at 110oC for 60 minutes at sample of 3 ES 10% was at 178.3 ml / min.

Virtual Casting: State of the Art in Metal Casting Simulation Tools

The demands on the productivity and robustness of metal casting processes for high quality components are continuously increasing. Moreover, the financial considerations necessitate meticulous and reliable planning of the entire casting process before it is actually put into practice. A holistic approach to perform cradle to grave analysis of cast products is simulation-based metal casting. This method allows engineers to model, verify, and validate the process followed by its optimization and performance prediction in virtual reality. This paper provides insights on state of the art in simulation-based metal casting with reference to some case studies. Casting simulations software, mathematical models and solution methods, and casting process simulation together with the results obtained are clearly explained. The current practices revealed extensive utilization of simulation packages for defect minimization, yield maximization, and improved quality. The ongoing research on integration of casting simulations with mechanical performance simulations makes it possible to analyze the serviceability of cast parts. The reliability of cast part in service with dynamic loading of varying thermal and mechanical load cycles can be predicted through this integration. However, more rigorous work is needed in this area, particularly by developing the reliability prediction modules embedded in advanced simulation tools.

Virtual Casting: State of the Art in Metal Casting Simulation Tools

The demands on the productivity and robustness of metal casting processes for high quality components are continuously increasing. Moreover, the financial considerations necessitate meticulous and reliable planning of the entire casting process before it is actually put into practice. A holistic approach to perform cradle to grave analysis of cast products is simulation-based metal casting. This method allows engineers to model, verify, and validate the process followed by its optimization and performance prediction in virtual reality. This paper provides insights on state of the art in simulation-based metal casting with reference to some case studies. Casting simulations software, mathematical models and solution methods, and casting process simulation together with the results obtained are clearly explained. The current practices revealed extensive utilization of simulation packages for defect minimization, yield maximization, and improved quality. The ongoing research on integration of casting simulations with mechanical performance simulations makes it possible to analyze the serviceability of cast parts. The reliability of cast part in service with dynamic loading of varying thermal and mechanical load cycles can be predicted through this integration. However, more rigorous work is needed in this area, particularly by developing the reliability prediction modules embedded in advanced simulation tools.

Microstructure Analysis of Hydroxyapatite Coating on Stainless Steel 316L Using Investment Casting Technique for Implant Application

Osteoporosis and traffic accident are major factor that causes bone fracture in Indonesia. One of solution for the bones fracture treatment is by using fixation implant that has similar characteristics with the human bones. Stainless Steel (SS) 316L is one of biomaterial that has been used as an implant material due to its corrosion resistance, good biocompatibility, and excellent mechanical properties. However, the bioactivity properties of the material is needed to improve by coating it with hydroxyapatite (HA). In this research, HA was coated to the surface of 316L SS by using investment casting technique. A slurry of HA was poured into casting cavity surface prior to metal casting process, and then followed by sintering at temperatures of 850oC, 900oC, and 950oC. Characterization of HA coating layer on specimen surface was conducted by Optical Microscope, Scanning Electron Microscope (SEM), and Energy Dispersive X-Ray (EDX). Hardness of the samples was measured by Vickers Hardness Tester. Result of the experiment shows that the invvestment casting is successfully to coat the HA on the SS 316L surface. Pouring method produces HA layer with thickness (spongy and porous surface) in the range of 60 µm - 110 µm. The increasing of sintering temperature increases the hardness number of the surfaces, and affect the purity of HA, but it is not related to coating thickness. Optimum sintering temperature is obtained at 900oC which produces the best calcium and phosphate ratio. The investment casting method is found as a simple and non-expensive technique that can be used to coat HA powder to SS 316L that produces good properties and optimum crystallinity of HA that suitable for orthopedic implant application.

Manufacturing Technology - I Laboratory Manual

To understand about various concept and methodology on the metal casting, machines, machining and metal joining process and practice the various operations that can be performed in lathe, shaper, drilling, milling machines and welding. To equip with the practical knowledge required in the manufacturing industries.

Improvement of the metal casting process and refractory equipment design in the intermediate ladle ‒ open jet ‒ the continuous billet caster mold's installation

The steel flow and refractory arrangement of the intermediate ladle (IL) ‒ open jet (OJ) ‒ continuous casting machine (CCM) mold's installation are regarded in the article. The specifics of the metal flow controlling are mentioned. The structural features of the continuous billet caster which maintain the effective metal flowing through the IL ‒ OJ ‒ CCM mold installation are presented. The improving of the installation design allows the expedient metal flows and provides the billets' quality upgrading.

Influence of resin flow on shrinkage of additive manufacturing coated sand molds

Coated sands are used extensively for additive manufacturing sand molds in the metal casting process, and the packing structure changes caused by the resin flow promote the shrinkage and deformation of the part. During the coated sand heating, the resin on the surface flowing to the contact points of the particles forms the resin neck and causes particles to pack close to each other. In this work, the diameters of the coated ceramsite sand before and after heating were measured based on in-situ experimental observations with image measuring apparatus and blue laser, to obtain the relationship between resin coating thickness and the particle diameter. The particle packing model was established to describe the particles’ achievement of a stable state one by one. A re-packing simulation was then performed after reducing the particle diameter according to the resin coating thickness, to obtain the shrinkage ratios at different particle size distributions. It was found that the resin coating thickness increased from 0.8 to 2.3 μm as the particle diameter increased from 107 to 500 μm, for the coated ceramsite sand with the resin content of 2wt.%; the shrinkage ratio decreased first and then increased as the particle diameter increased. The experimental minimum shrinkage ratio was 3.28%, and the corresponding particle diameter was 300–375 μm, while the minimum shrinkage ratio obtained by simulation was 3.43%, and the corresponding particle diameter was 214–300 μm. After mixing the five groups proportionally, the shrinkage ratios of the simulation and experiment dropped to 2.81% and 3.04%, respectively, indicating the best results.

Experimental and numerical thermal analysis of open-cell metal foams developed through a topological optimization and 3D printing process

This study focuses on the thermal analysis and comparing a lattice model and an optimized model of open-cell metal foams manufactured thanks to a metal casting process. The topological optimization defines the complex geometry through thermal criteria and a plaster mold reproduces it in 3D printing to be used in casting. The study of the thermal behavior conducted on the two open foam metal structures is performed based on several measurements, as well as numerical simulations. It is observed that the optimized metal foam presented less and non-homogenous local temperature than the lattice model with the gap of about 10 °C between both models. The pore size and porosity significantly affect the heat transfer through the metal foam. The comparison between numerical simulations and experimental results regarding the temperature fields shows a good agreement allowing the validation of the developed three-dimensional model based on the finite element method.

Investigation of alternative ways for recycling waste foundry sand: an extensive review to present benefits

Foundry sand, an indispensable component of the metal casting process, is discarded after a number of metal casting operations. Virgin sand is then required for any new casting processes, and the spent foundry sand is treated as waste, resulting in huge amounts of discarded sand being either stockpiled or dumped into landfills. This results in a wide scale consumption of natural resources despite the fact that this “waste” can be recycled as a viable resource in various engineering processes. To this end, this study represents a detailed investigation into the possible uses for waste foundry sand. Obtained results concluded that this material can best be utilized in highway and hydraulic barrier construction, as well as low strength concrete production. Thus, the recycling of waste foundry sand results in the conservation and saving of natural and financial resources.

Prediction and validation of shape distortions in the simulation of high pressure die casting

The use of the thermomechanical simulation is very infrequent in the metal casting industry although the associated results are really useful for the manufacturing process. The main reasons are the complexity, the long calculation times and the difficulties to interpret the results.The parts manufactured by metal casting processes cool from its filling temperature to ambient, which causes a certain stress-strain state. Although the stress levels might be significant, the main worry of the foundrymen is usually the shape distortion. That is, the mismatches between the desired dimensions and the real ones. The problem is that the results obtained from numerical simulation are not directly useful to cover this industrial necessity.This work presents the prediction obtained using the thermomechanical simulation for the final dimensions of a component manufactured in aluminium alloy by high pressure die casting (HPDC) and its validation with the final dimensions of the manufactured component. The methodology established to forecast the mismatches with the reference geometry is also detailed, as it may be useful to encourage the use of this type of simulation in the metal casting industry.

Demand-side management via optimal production scheduling in power-intensive industries: The case of metal casting process

The increasing challenges to the grid stability posed by the penetration of renewable energy resources urge a more active role for demand response programs as viable alternatives to a further expansion of peak power generators. This work presents a methodology to exploit the demand flexibility of energy-intensive industries under Demand-Side Management programs in the energy and reserve markets. To this end, we propose a novel scheduling model for a multi-stage multi-line process, which incorporates both the critical manufacturing constraints and the technical requirements imposed by the market. Using mixed integer programming approach, two optimization problems are formulated to sequentially minimize the cost in a day-ahead energy market and maximize the reserve provision when participating in the ancillary market. The effectiveness of day-ahead scheduling model has been verified for the case of a real metal casting plant in the Nordic market, where a significant reduction of energy cost is obtained. Furthermore, the reserve provision is shown to be a potential tool for capitalizing on the reserve market as a secondary revenue stream.

Analyze the effect of Molybdenum on Heat Resistance Stainless Steel Casting SCH 22

There was SCH 22 component named hanger that is produced by casting, where it is one of the components applied at 1100°C work temperature. Problems on the product is the occurrence of scaling, causing the the function failure and shortening its lifetime. Generally, this scaling occurs when the material is exposed to high temperature, then kinds of iron oxide layers are arisen such as FeO, Fe3O4, and others. Based on the literature, Molybdenum can be added to the SCH 22 with maximum limit of 0.5%. The purpose of this study is to know the influence of Molybdenum to the mechanical properties and analyze the phenomenon of scaling on Heat Resistant Stainless steel Casting (SCH 22). It is expected that molybdenum could increase the scaling resistance in the high temperature. The method is making specimens through metal casting process where the molybdenum content are made to 0.3%, 0.7%, 1.1%. Each specimen should be heated at 1150°C and held for 4 hours. Then the mechanical strength and micro structure are observed to see the effect such molybdenum addition. The result is obtained that the 0.7% addition of molybdenum element can reduce the degradation due to scaling on Heat Resistance Stainless Steel Casting SCH 22.

Energy diagnosis and structuring an energy saving proposal for the metal casting industry: An experience in Colombia

The increase of energy efficiency is an option to reduce greenhouse gas emissions (GHG). This benefits the industrial sector by reducing the energy consumption required to manufacture products, increasing production levels, and improving the competitiveness of the industry at a national and international level.In this project, a diagnosis of the energy efficiency of the ferrous and non-ferrous metal casting industrial sector in the Valle del Cauca and Cauca region was carried out. This sector represents 7% of Colombia’s total industries and consumes about 10% of the total energy consumed by all industries; of which 84.7% corresponds to energy of thermal origin, while the remaining 15.3% corresponds to electric power, with a total consumption for the year 2012 of 232.069 terajoules.In the Valle del Cauca Department, there are 24 establishments engaged in the casting of metals, i.e. 17.3% of Colombia’s total metal casting industry. The project involved five metal casting businesses from the department of Valle del Cauca and Cauca, in which the energy consumption, along with the respective loss of energy in the metal casting process were evaluated. The results of the energy diagnosis show that energy losses through the fuel gases are the main source of energy loss in the aluminium casting systems, the heating of steel billets and the heat treatments, representing a total loss of 54.2%. One of the causes is the average temperature of the flue gas output in different industrial processes, 654.8 °C, along with the high percentages of excess air in the combustion. The proposals intend to reduce these sources of energy loss through the use of available measures or technologies that could make the industrial processes more efficient and competitive. These include: heat recovery from fuel gases to heat combustion air (RCGCA), air–fuel ratio control (CRAC), implementation of oxygen enriched technology (EACOX), implementation of a system of electric power generation by means of an Organic Rankine Cycle (ORC), self-restoring or self-regenerating burners (QAR), flameless burners (QF) Combustion gas heat recovery to preheat the raw material (RCGCM). The multi-criteria method used to select the best proposals for the energy efficiency program in the metal casting sector is known as the analytic Hierarchy Process (AHP), where it is concluded that the most feasible proposals are the control of the air–fuel ratio (CRAC), heat recovery of the fuel gases to heat the air (RCGCA), the implementation of self-recuperative or self-regenerating burners (QAR), and the implementation of an Organic Rankine Cycle for the generation of electric energy (ORC).

Development of a finite element/discontinuous Galerkin/level set approach for the simulation of incompressible two phase flow

In this paper, we present a combined finite element/ discontinuous Galerkin/ level set method to simulate the incompressible two phase flow. The level set method is employed to capture the moving interface because of its simplicity and efficiency when dealing with the significant interface deformations. Due to the hyperbolic nature of the level set equation and the level set re-initialization equation, we apply the second order Runge Kutta Discontinuous Galerkin (RKDG) method to get the stable and precise results. Moreover, in order to obtain the accurate velocity field, the hybrid continuous and discontinuous Galerkin approach is utilized to solve the incompressible Navier–Stokes equations. In our combined method, there is no need to re-initialize the level set function in every time step and the re-initialization process is implemented after suitable time steps. The desirable mass conservation property is able to be guaranteed with a mass correction technique in the combined algorithm. In addition, the stabilization terms can be avoided in the whole computational process. Several challenging problems, i.e., a rising bubble, the dam-break flow, the Rayleigh–Taylor instability, and the complex metal casting process in the engineering applications are investigated to evaluate the feasibility, validity and practicability of our approach for solving the problem of the incompressible two phase flow.

Experimental study on bag filtration enhanced by magnetic aggregation of fine particles from hot metal casting process

Bag filtration experiments enhanced by pre-aggregation of fine particles from hot metal casting process with size range of 0.3–10μm in magnetic field were conducted in this work. There is a distinct difference in magnetization process between particles from cast house and coal-fired power plant. The influences of magnetic flux density and gas velocity on particle aggregation and total particle removal efficiency were investigated. The experimental results showed that bigger particles are easily affected by magnetic field and the smaller particles are easily affected by flow field. Although higher magnetic flux density can improve the aggregation of bigger sized particles at a constant gas velocity, combined with the effect of particle size distribution, the total particle number concentration increases as the average gas velocity increases, which would result in the decrease of the total particle removal efficiency. When the total particle mass concentration is 1000mg/m3, the magnetic flux density is 0.08T and the gas velocity is 3.0m/s, the highest total particle removal efficiency reaches 99.77%. When particle magnetization reached saturation, the magnetic flux density will reduce the total particle removal efficiency.

Application of Taguchi and RSM techniques for optimising the parameters of pressure die casting process

Most of the automotive and allied components in today's world are produced by metal casting processes. However, the casting process industries suffer from poor quality of castings due to involvement of large number of process parameters. The primary intent of this paper is to enhance the quality of aluminium die casting products using optimisation techniques such as Taguchi and response surface methodology. In this study, some of the factors that have reasonable influence on blow holes defect are identified. Each factor is considered with three levels and Taguchi technique is employed. Analysis of variance table is generated to determine the statistical significance of the parameters. Response graphs are plotted to determine the preferred level for each parameter. By using the Minitab soft tool, response surface methodology is carried out. The regression model, surface and contour plots are developed to identify the most contributing process parameter. Among the selected process parameters, the degassing frequency is noted as greatest influencing factor up to 47% on response, next influencing factor as metal temperature with 45% contribution on response. The highest level of metal temperature and lowest level of degassing frequency are found as optimum level to decrease the blowhole defect.

Application of Taguchi and RSM techniques for optimising the parameters of pressure die casting process

Most of the automotive and allied components in today's world are produced by metal casting processes. However, the casting process industries suffer from poor quality of castings due to involvement of large number of process parameters. The primary intent of this paper is to enhance the quality of aluminium die casting products using optimisation techniques such as Taguchi and response surface methodology. In this study, some of the factors that have reasonable influence on blow holes defect are identified. Each factor is considered with three levels and Taguchi technique is employed. Analysis of variance table is generated to determine the statistical significance of the parameters. Response graphs are plotted to determine the preferred level for each parameter. By using the Minitab soft tool, response surface methodology is carried out. The regression model, surface and contour plots are developed to identify the most contributing process parameter. Among the selected process parameters, the degassing frequency is noted as greatest influencing factor up to 47% on response, next influencing factor as metal temperature with 45% contribution on response. The highest level of metal temperature and lowest level of degassing frequency are found as optimum level to decrease the blowhole defect.