Sand Mold Casting Research Articles

Foundry Coatings - Review

The main purpose of this publication is to present the founding stages of the foundry industry and its fundamental importance to the engineering sector. The second focus is to examine the technology of casting in sand molds and more specifically those based on no-bake process(chemically hardening). The auxiliary materials used for the production of sand molds and their importance for the quality of the final part-casting are examined in detail. Special attention is paid to refractory coatings, and in particular those with graphite filler, because of their wide application. The main chemical parameters are presented and the need to study their geometric and tribological characteristics and their influence on the quality of manufactured castings is emphasized. Until now, the author of the publication has studied the micro hardness, roughness, friability and gas permeability of refractory coatings, for which parameters no previous information on similar tests has been found. The research carried out was financed under phd project No. 222ПД0005-05 – TU Sofia, Bulgaria.

The current state and prospects for the development of the Lost Foam Casting process

Increasing the capacity of foundry production can play a decisive role in the recovery of the machine-building and defense sectors of the Ukrainian industry. The current state and prospects for the development of foundry technology — Lost Foam Casting (LFС) process, as well as its possibilities for increasing the volume of metal processing into finished parts on the example of China, are considered. For foundries of low-volume casting, which need fast production of foundry patterns, the LFС method contributes to the minimization of capital and current costs. The melting, casting and finishing processes in LFС are the same as in typical foundry processes, with the exception of the need for a 30—50 oC higher pour temperature. The process of making patterns from polystyrene foam (EPS) has been developed in several variants and can initially be implemented on a small scale to obtain trial castings. An existing foundry, after successful trials with a simplified LFC process, can increase batch sizes of castings along with increased investment in tooling and equipment to do so. Mechanical processing when obtaining foam patterns is beneficial for volumes of less than 100 castings, and for a series of more than 1000 castings (common use of LFС) sintering of granulated EPS in molds is used, including the use of automated equipment for this. In terms of the amount of solid and gaseous waste, LFС in forms with dry vacuumed sand is ecologically superior to most foundry processes. The LFС process is constantly developing and improving, easily includes 3D technologies in the sequence of its operations and is amenable to digitization, automation, robotization and scaling, refers to high-precision casting in sand molds using noncapital- intensive equipment. The example of China shows the possibility of a rapid increase in the production of castings in a wide range of their weight, nomenclature and type of used metal alloys.

Solidification pattern of 4.5%Si ductile iron in metal mould versus sand mould castings

Solidification pattern of 4.5%Si ductile iron in metal mould versus sand mould castings

Microstructure and high-temperature mechanical properties of new-type heat-resisting aluminum alloy Al6.5Cu2Ni0.5Zr0.3Ti0.25V under the T7 condition

Making use of the low-pressure sand mold casting preparation Al6.5Cu2Ni0.5Zr0.3Ti0.25V alloy. After T7 heat treatment, microstructure observation shows that the average grain size of the Al matrix is 150 μm, and the second phase is θ'-Al2Cu, Al7Cu4Ni, Al3M (M = Ti, Zr, V). The tensile strength is 127.5 MPa, the yield strength is 108Mpa, and the elongation is 16.11 %. The θ'-Al2Cu phase in the grain, a small amount of Al3M (M = Ti, Zr, V) thermal stable phase, and the Al7Cu4Ni phase at the grain boundary make the alloy exhibit excellent high-temperature mechanical properties at 350℃.

RAFFMETAL EN AB-Al Si10Mg (EN AB-43000)

Abstract RAFFMETAL EN AB-Al Si10Mg (EN AB-43000) is a heat-treatable, aluminum-silicon-magnesium casting alloy in ingot form for remelting. It is used extensively for producing sand and permanent mold castings for applications requiring a combination of excellent casting characteristics, high strength with fair elongation, and fair corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: Al-491. Producer or source: Raffmetal S.p.A.

Influence of the mold type on the mechanical properties of the piston alloy with nano alumina in casting and metal mold

This research is an experimental comparison study to show the influence of mold type casting on mechanical properties. The study considers the aluminum alloy of a gasoline engine piston with nanoparticles alumina Al2O3 size 25 nm manufactured in two types of molds. Sand mold and cast-iron mold were selected to cast the aluminum composite components. A systematic comparative study of tensile strength and hardness properties of cast aluminum components is made on sand and metal molds production. The nano powder can add to enhance the mechanical properties must not exceed 4 % for metal and sand mold casting. According to data for hardness, adding nano alumina powder has minimal impact on metal mold casting, but it significantly improves sand casting. From a financial standpoint, metal casting provides higher economic values for making piston aluminum castings. The hardness rises as the alumina content does in two molds as compared to the obtained specimen. It demonstrates that the highest hardness occurs at 4 % alumina in the sand-casting mold and at 6 % alumina in the metal. When the compositions of the casting materials are the same, a comparison of the fracture morphology between sand and mold casting reveals more ductile fractures for metal molds compared to brittle fractures in sand cast by large silicon separation grains because of higher grain growth in sand casting by longer solidification time. The same is seen in mold casting, which exhibits reduced ductility due to the alumina nanoparticles' dispersion strengthening process in the aluminum matrix. This arises as a result of nano alumina dispersion acting as barriers to dislocation motions in the aluminum matrix, enhancing strength but reducing ductility.

Determination of flow distance of the fluid metal due to fluidity in ductile iron casting by artificial neural networks approach

Abstract Ductile irons (DIs) have properties such as high strength, ductility, and toughness, as well as a low degree of melting, good fluidity, and good machining. Having these characteristics make them the most preferred among cast irons. The combination of excellent properties, especially in DI castings with a thin section, make it an alternative for steel casting and forging. But in the manufacture of thin-section parts, fluidity characteristics need to be improved and the liquid metal must fill the mold completely. The fluidity of liquid metal is influenced by many factors depending on the casting processes such as material and mold properties, casting temperature, inoculation, globalization, and grain refinement. In this study, an artificial neural network (ANN) model has been developed that allows for determining the flow distance of the liquid metal in the sand mold casting method under changing casting conditions of DI. Thus, the flow distance was estimated depending on the cross-sectional thickness during the sand casting under changing casting conditions. The experimental parameters were determined as casting temperature, liquid metal metallurgy quality, cross-sectional thickness, and filling time. Filling modeling was performed with FlowCast software. When the results were examined, it was seen that the developed ANN model has high success in predicting the flow distances of the liquid metal under different casting conditions. The calculated coefficient of determination (R 2) value of 0.986 confirms the high prediction performance of the model.

RIO TINTO C355.2

Abstract Rio Tinto C355.2 is a heat-treatable, aluminum-silicon-copper-magnesium casting alloy (3xx.x series). It is available in the form of ingots for remelting, to be used for the production of sand and permanent mold castings. Alloy C355.0 is a higher purity, low iron version of alloy 355.0. Both the alloys are similar, except the lower iron in C355.0 provides better elongation and somewhat higher tensile strength. Alloy C355.0 is used in premium, high strength applications where castings are usually heat treated for maximum strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-490. Producer or source: Rio Tinto Limited.

An improvement of manufacturing process using 3D printing technology for overhead line components on railway electrification

In an electric railway, an overhead contact system (OCS) is assembled with many components, and it maintains a voltage of 25 kV to supply electricity to the electric trains. As electric trains grow faster, the overhead line comes to employ a diverse range of materials to deliver electricity and maintain high tension. Overhead lines supply electricity to electric trains through mechanical contact with a pantograph, and since they are not fault-tolerant, they require high reliability. That makes it take a long time to develop and supply components and also makes it difficult and time consuming to apply new materials or new designs to components. This study proposes a manufacturing process for overhead line components using 3D printing technology. For this, a clevis terminal clamp for high-speed railway was chosen and a design drawing was created with 3D scanning. For molding, additive manufacturing technology was used. The study castings were obtained by applying precision casting and sand mold casting methods, respectively, and their elongation and tensile strength were compared with products made with a traditional method.

Effect of the Type of Inorganic Binder on the Microstructure and Properties of AlSi7Mg Alloy Castings Made by Ablation Casting Technology.

The results of studies on the effect that the type of binder and casting technology exert on the microstructure and properties of AlSi7Mg alloy castings are discussed in this paper. Comparative tests were carried out on three casting manufacturing technologies, i.e., conventional sand mould casting and cooling process, metal mould (die) casting, and sand mould casting with ablation breakdown of mould and cooling of castings. Moulds were made from four different sand mixtures with inorganic binders hardened by various technologies. The microstructure of test castings was examined at three different levels, i.e., in the upper part, central part, and lower part of each casting. The tensile test at room temperature was carried out in accordance with standards. The experimental results showed differences in the microstructure of castings. The differences resulted from changes in the crystallisation path due to the use of three different casting technologies, ensuring different rates of heat dissipation from castings; they were also due to the shape of castings. It has been shown that castings made by ablation technology are characterised by a high degree of the microstructure refinement (SDAS reduced by 18–30%), which gives higher strength properties than the properties of castings made in conventional sand moulds. Samples taken from castings made by the ablation technology in moulds with phosphate binder and microwave-hardened geopolymer binder were characterised by the mechanical properties comparable to gravity die castings.

Wear behaviour of the Ni-Cu alloy hybrid composites processed by sand mould casting

ABSTRACT Hybrid Metal Matrix Composites are rising in demand to satisfy advanced technological applications due to their improved mechanical and wear properties. In the present work, a sand moulding process is used to develop the Ni-Cu alloy hybrid metal matrix composites (HMMCs) reinforced with aluminium oxide (Al2O3) and titanium dioxide (TiO2) particles. According to ASTM standard, the fabricated Ni-Cu alloy HMMCs undergo microstructure and tribological evaluation. In this study, tribological properties like wear and coefficient of friction analysis are performed on a pin-on-disc wear testing machine with varying (200, 300 and 400 rpm) speeds (20, 30 and 40 N), loads (1 m/sec), sliding velocity. Micrographic images show fairly uniform distribution of the reinforced elements Al2O3 and TiO2 in the Ni-Cu alloy matrix. An analysis of EDS and XRD reveals the presence of reinforced particulate matter in the Ni-Cu alloy matrix. The wear rate of hybrid composites (0.000366 mm3/N-m) is found to decrease (25%) with an increase in 9 wt. % of TiO2/Al2O3 reinforcement when compared to the base alloy (0.000828 mm3/N-m). It can be observed that the addition of Al2O3 and TiO2 particulates in the base alloy nickel, it’s reduced the co-efficient of friction (0.78) at various loads and speeds.

Metal Casting and Sand Mold: (2) Education Materials for Sand Mold Castings

Metal Casting and Sand Mold: (2) Education Materials for Sand Mold Castings

Influence of Palm Kernel Shell Powder on the Mechanical Properties of Inoculated Gray Cast Iron

The use of agricultural by-products and waste materials as fillers and additives to produce different mix designs with enhanced properties is one of the ways researchers are shifting focus to seek and develop materials that rely on renewable resources. The present research investigates the influence of Palm Kernel Shell Powder (PKSP) on the mechanical properties of inoculated Gray Cast Iron (GCI). Five specimens consisting of sample C0 (0.3%FeSi, 0%PKSP), Sample C3 (0.3%FeSi, 0.3%PKSP), sample C6 (0.3%FeSi, 0.6%PKSP), sample C9 (0.3%FeSi, 0.9%PKSP), and sample C12 (0.3%FeSi, 1.2%PKSP) were developed using sand mold casting method, the chemical analysis, and their mechanical properties (tensile, hardness, and microstructures) were evaluated. The chemical composition shows that the produced gray cast iron solidified within the hypereutectic cast iron range (Carbon Equivalent, CE > 4.5), while the microstructure reveals through the graphite flakes distribution that the produced gray cast iron consists of type A graphite. The highest tensile strength and hardness values were observed in sample C3 with tensile strength and hardness values of 155.97MPa and 156.74 BHN respectively. From the result obtained, an increase in both tensile and hardness values was observed up to 0.3% PKSP addition, beyond this amount, shows a decrease in both tensile strength and hardness values for the developed gray cast iron samples.

Investigation of the effect of the addition of grain refiner and modifier addition on wear properties in sand and permanent mould casting of A357 and A380 aluminium alloys

ABSTRACT The aim of this study is to improve the tribological behaviour of aluminium alloys by using grain refiner and modifier. The effects of Al5Ti1B grain refiner and Al10Sr modifier additives on friction and wear properties on A380, A357 alloys produced by pouring sand andpermanent mould casting were investigated. Abrasion tests were carried out under dry conditions against St1040 steel disc using a pin-disk system with 20 N load and 1.0 m/s sliding speed. It was determined that grain refiner and modifier additives decrease the friction coefficient and increase the wear resistance. It was determined that the samples produced by permanent mould casting method decreased the friction resistance by 9% and the abrasion resistance increased by 40% compared to the samples produced in sand mould. The lowest wear rate was obtained in A380 alloy with TiB and Sr added with a value of 4.87 × 10–11 m2/N.

Вплив швидкості охолодження на структуроутворення сплаву АМ4,5Кд (ВАЛ10)

High-strength cast aluminum alloy AM4.5Kd (VAL10) belongs to the Al-Cu system and due to the combination of a high level of physical, mechanical and operational properties, is widely used in high-tech industries and technology: aviation, space, shipbuilding, transport. Products from the alloy AM4.5Kd (VAL10) are obtained by all known methods of casting (in sand molds, in a chill mold, under pressure), differing in cooling rates. This has a significant effect on the structure and properties of the alloy, not only in the as-cast, but also in the heat-treated state, which determines the relevance of scientific work in this direction. The article presents the results of a study of the microstructure of the AM4.5Kd (VAL10) alloy with a change in its cooling rate during the curing process (Vcool.) from 0.4 °C/s to ≥ 105 °C/s. The alloy was melted, refined and, at a temperature of 750°C, poured into molds with different heat sinks. It is shown that an increase in the cooling rate during the hardening process leads to a decrease in the size of structural components, in particular, aluminum (Alα) solid solution crystals and to an increase in their microhardness. At a cooling rate of 0.4 °C/s, corresponding to solidification in a sandy form, primary Alα crystals are formed in the form of coarsened dendrites with an average size slightly larger than 800 μm, along the boundaries of which a fine network of particles of Al3Ti, Al12Mn2Cu phases and Alα+СuАl2 eutectics is formed. With an increase in the cooling rate, the branching of the dendrites and the volume fraction of the finely differentiated eutectic increase, the cooperative growth of phases in which is maintained throughout the entire range of cooling rates studied. The value of the dendritic parameter of the solid solution of aluminum regularly decreases with a practically unchanged shape factor of its crystals, which is almost up to Vcool. ≈ 105 °C/s is from 1.45 to 3.15. A similar dependence of the change in the macrograin size on the cooling rate was not found. Its anomalous growth was recorded at a cooling rate of ≥ 120 °C/s, at which the macrograin size is commensurate with the alloy cooled at a rate of 0.4 °C/s. In the work, such a discrepancy is explained from the standpoint of the theory of the nucleus and growth of crystals. Keywords: cooling rate, microstructure, AM4.5Kd (VAL10), structure formation, macrograin size.

RIO TINTO 355.2

Abstract Rio Tinto 355.2 is a heat-treatable, aluminum-silicon-copper-magnesium casting alloy (3xx.x series). It is available in the form of ingots for remelting, for the production of sand and permanent mold castings. It is a high-strength alloy with many desirable characteristics. The presence of copper in alloy 355.0 increases strength but reduces corrosion resistance and ductility. This alloy is less ductile than 356.0. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-486. Producer or source: Rio Tinto.

The Effect of Zirconium as an Alloying Additive on the Microstructure and Properties of AlSi9Mg Alloy Cast in Sand Moulds

The Effect of Zirconium as an Alloying Additive on the Microstructure and Properties of AlSi9Mg Alloy Cast in Sand Moulds

Additive manufacturing integrated Casting- A review

Integration of advanced manufacturing technology with traditional methods is a need for the current situation. Additive manufacturing technology is the most advanced manufacturing technology adopted by various industries. Foundry industries share a big percentage among the other manufacturing industries and are also capable to manufacture parts with complex geometry which are otherwise not possible or very difficult to produce with other manufacturing processes. Integration of additive manufacturing technology with the casting process can bring a new evolution in the foundry industry. The traditional casting process involves several complex and time-consuming steps, along with costly tooling. To make mold or core or pattern for small production is not an economical task. In this study casting manufactured by Additive manufacturing integrated casting is compared with conventional cast and comparison has been done based on dimensional accuracy, strength, time, surface roughness, and amount of material used. The main focus has been given to investment casting and sand mold casting as they are widely used for the production of cast parts. Moreover, challenges/limitations, current trends and future scope in additive manufacturing integrated casting have been discussed. This study helps the researcher to find a novel methodology to improve the capability of additive manufacturing integrated casting for various applications in the 21st century.

Evaluation of Microstructure and Mechanical Properties of Al-Cu-TiO<sub>2</sub>-ZrO<sub>2</sub> Composites

Different types of aluminium alloy based composites are being developed nowadays by using various types of the reinforcements to get better mechanical properties. In this research work, a new aluminium-copper alloy based composite reinforced with 5%, 7.5% and 10% of titania (TiO 2 ) and zirconia (ZrO 2 ) mixer have been fabricated and also investigated for mechanical properties like surface hardness, compressive strength, tensile strength and micro-structural characterization has been done by using microscope, energy dispersive spectroscopy, scanning electron micro-graph with X-ray elemental mapping and X-Ray powder diffraction. The new composite has been prepared by combining three processes like sand mould casting, temporary wax pattern and stir casting which has never been used before for casting. Design of experiment has been done by employing Taguchi L18 orthogonal array in this study. It has been found that all the three mechanical properties have been escalated due to reinforcement of abrasive particles in the base alloy and the improved results of Al/Cu composites in terms of percentage are 29.72% for hardness, 31.46% for tensile strength and 43.29% for compressive strength successfully achieved in this work.

Green strength properties of waterjet abrasive waste as potential composition in green mould by Taguchi and ANOVA approach

The sand casting process still continues today due to the cost-effectiveness of materials and processes. There is a wide variety of castings related to composition and size, but silica sand is widely available from coastal line mining and has a negative impact on the environment. Moreover, waste from waterjet cutting of non-ferrous and ferrous metals is practically unhazardous and may potentially be used in sand casting mould. The aim of this paper is to optimize the proportion of coal dust, water and bentonite added to the silica sand mixture and the waterjet cutting abrasive waste as a new way of handling waste with the potential to be used in sand casting manufacturing. The method used was L9 orthogonal array optimization and the composition was qualitatively measured using a green compression strength test and a green shear strength test. Factors were evaluated using the analysis of variance (ANOVA) to find the the critical factors while confirmation test was conducted for the optimal material proportion. The study concluded that the ideal ratio for silica sand mixture with waterjet abrasive waste is bentonite-12%, coal dust-5%, and water-7% for green compression strength while bentonite-12%, coal dust-6%, water-7% for green shear strength. With proper selection, the incorporation of waterjet abrasive waste into the green sand mixture is promising to potentially be used in green sand mould casting without undermine the quality of mould.