Archives of Foundry Engineering continues the publishing activity started by Foundry Commission of the Polish Academy of Sciences (PAS) in Katowice in 1978. The initiator of it was the first Chairman Professor Dr Eng. Wacław Sakwa – Corresponding Member of PAN, Honorary Doctor of Czestochowa University of Technology and Silesian University of Technology. This periodical first name was „Solidification of Metals and Alloys” , and made possible to publish the results of works achieved in the field of the Basic Problems Research Cooperation. The subject of publications was related to the title of the periodical and concerned widely understand problems of metals and alloys crystallization in a casting mold. In 1978-2000 the 44 issues have been published. Since 2001 the Foundry Commission has had patronage of the annually published “Archives of Foundry” and since 2007 quarterly published “Archives of Foundry Engineering”. Thematic scope includes scientific issues of foundry industry: Theoretical Aspects of Casting Processes, Innovative Foundry Technologies and Materials, Foundry Processes Computer Aiding, Mechanization, Automation and Robotics in Foundry, Transport Systems in Foundry, Castings Quality Management, Environmental Protection. The journal website is being gradually updated as part of the migration from journals.pan.pl. The information on this page is current.
The Katowice Branch of the Polish Academy of Sciences
Comparative Analysis of Fresh and Reclaimed Core Sand in Foundry Reuse Applications
This study examines chemical composition and grain morphology in fresh and reclaimed silica sand used for core production in an industrial iron foundry. The aim was to characterise in-house core sand before and after dry mechanical reclamation and to assess how repeated use affects element distribution and grain shape. Fresh and reclaimed sand samples from the core sand system were gathered and divided into standard size categories through sieving. The material was subsequently organised into fine, medium, and coarse layers using a stratified approach. X-ray fluorescence (XRF) was used to determine the chemical composition, while dynamic image analysis assessed grain shapes by examining roundness at the Q10, Q50, and Q90 percentiles. Selected samples were additionally examined using scanning electron microscopy (SEM). Reclaimed sand, especially fine particles (<0.125 mm), has higher levels of MgO, Al₂O₃, CaO, and C than fresh sand due to accumulated bentonite, binder residues, and dust. SiO2 remains the main component but is slightly lower in reclaimed material due to the higher share of these additional phases. Na₂O decreases slightly in reclaimed sand, while K₂O shows minimal variation between fractions and layers. Grain roundness differs only moderately and depends on size: fresh sand is more rounded in the fine fractions (63 μm and 90 μm), both sands have almost identical roundness in the 125–355 μm range, and reclaimed sand is only slightly more rounded in the coarse fractions (500–710 μm). Scanning electron microscopy (SEM) images indicate that both sand samples exhibit generally similar grain morphologies. However, differences in surface characteristics are likely attributable to a thin coating of fine clay and binder particles present on the reclaimed grains.
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Optimization of the High Pressure Die-Casting Process to Reduce Porosity
The main problem with the use of pressure castings from aluminium alloys for, among others, critical parts in the automotive industry is the presence of porosity. Obtaining castings with reduced porosity is a very difficult task, requiring a number of changes in relation to the classic pressure casting process. This basic defect limits the area of application of pressure castings. In addition to reduced tightness and inadequate external surface quality, it can reduce the strength and/or plastic properties of the castings. One of the solutions to avoid problems in the production of high-quality, tight and at the same time thin-walled and durable castings from Al alloys can be the use of a special high-pressure casting solution using the so-called "vacuum". The use of the Vacuum system in high pressure die-casting can significantly reduce the porosity of castings. The amount of gas present in the pressure casting is influenced by the geometry of the part and the process parameters. At standard temperature and pressure, the gas content inside die-cast parts typically ranges from 10 to 50 cm3/100 g. Using vacuum casting, gas content below 10 cm3/100 g, or even 1 cm3/100 g, can be achieved, allowing simplified heat treatment and welding of the parts. The article presents selected studies on reducing porosity in pressure castings using the Vacuum system. Microstructural tests, density tests, X-ray and CT, and a leak testing of the castings were carried out.
Simulation and Verification of Liner (ZGMn13Cr2) Investment Casting Based on Modified Porous Media Equivalent Thermal Conductivity Model
For the investment casting of ZGMn13Cr2 high-manganese steel porous liners, internal cavities can cause distortion in traditional numerical simulation of the temperature field and defect prediction. In this study, the Bruggeman porous medium equivalent thermal conductivity model was introduced and modified to suit porous castings. After calculating the overall porosity of the liner casting, an equivalent thermal conductivity scaling factor of 0.675 for the liner was derived based on the modified Bruggeman model, and simulations of the liner were carried out in ProCAST software using this correction factor. The simulation results show that the modified model significantly improved the uniformity of the temperature field and the synchronization of the solidification process, with more accurate shrinkage defect predictions. The maximum reduction in shrinkage volume at monitoring points reached 44.2%, and the uniformity of defect distribution was greatly enhanced. Finally, actual pouring of the liner product confirmed that the modified computational model was more consistent with the actual casting in terms of macroscopic forming, hole position accuracy, and defect distribution trends. This study provides a new approach for process simulation optimization of complex porous structure castings and offers practical experience for casting simulation and actual forming of porous products.
Optimizing Resin Dosage and Sand Grading to Enhance the Properties of 3D-Printed Furan Sand Molds
This study investigates the influence of resin content, curing agent ratio, curing time, and sand grading on the strength, gas permeability, and gas evolution behaviours of furan resin sand molds in 3D printing-based sand casting. The focus is on optimizing material usage and aligning with sustainable manufacturing objectives to minimize the waste. A multivariate quadratic polynomial regression model was developed through orthogonal experiments and microstructural characterization. The findings indicate that the addition of furan resin is crucial for determining the tensile strength, gas evolution, and permeability of sand molds. Under the process parameters of 2.0% resin content, 40% curing agent ratio, and 24-hour curing time, the sand mold demonstrated a tensile strength of 2.98 MPa, gas evolution of 10.4 mL/g, and permeability of 119.3 AFS. Further increasing the resin content beyond 2.0% resulted in a plateau in the strength gain, accompanied by a sharp increase in gas evolution. The application of an optimized sand grading ratio of 3 parts coarse (150-212 μm) to 7 parts fine (106-150 μm) led to comprehensive performance improvements: the tensile strength increased to 3.02 MPa, gas evolution was controlled at 11.2 mL/g, packing density approached theoretical optimum values, and surface roughness was significantly reduced to a Sa value of 43.478 μm. This study formulates a multi-objective optimization framework and strengthens the theoretical basis for furan resin sand molding in 3D printing, providing industrially viable solutions to minimize typical defects, such as gas porosity and sand adhesion, in real-world casting operations.
Development of a Measurement and Control Method Enabling the Determination of the Gas Phase Content in a Liquid Metal or Alloy
This article presents various possibilities for testing the degree of gassed of liquid metals. This phenomenon poses a significant problem in the foundry industry, therefore, it is crucial to conduct extraction processes and develop a rapid and accurate method for assessing the gas phase content in the alloy. In addition to analysing methods already known and used in industry and laboratories, the authors present possible research directions using innovative ideas. To confirm hypotheses, they build a test rig and then conduct a series of tests that yield interesting results. The authors studied a lead alloy (Pb-Sn). The alloy was analyzed under the same conditions, subjecting it to moderate and then intense gassed. The results were compared with those of a reference test of a ungassed alloy. It was observed that the ungassed alloy showed a linear increase in the resistance of the liquid metal over the tested temperature range. With the gassed charge, there were either slight changes or the resistance value remained constant over the tested temperature range. The research method not only provides a quick answer but also allows for determining whether the degassing process can be interrupted or should be continued. The method is based on examining the micro-resistance of the system at a given temperature using measuring probes placed in the liquid alloy. By examining a reference sample and determining its reference system parameters, the user can quickly assess the charge in terms of the degree of gassed for each subsequent batch of material prepared in the industrial process.
The Influence of Foundry Sand Type on the Hardening Process of Self-Setting Molding Sands Based on Urea-Furan Binder
The article presents the results of investigations on the influence of the type of sand matrix on the binding process of self-setting molding sands with an organic binder. The study encompassed molding sands prepared on matrices of quartz, reclaimed quartz, zircon, chromite, corundum, synthetic, and olivine sand (a “non-compatible” sand). For the preparation of the molding sands, a urea–furan resin Kalthartz U404 was used as the binder, along with an acidic hardener, Activator 100 T3. In the case of matrices compatible with the self-setting molding sand system with an organic binder, the resin content was 1.00 p.p.w., with a constant hardener-to-binder ratio of 50 %. During the study, a sieve analysis of the investigated sand matrices was conducted according to PN-83/H-11076, and the pH value was determined using a method refined by the authors based on BN-81/4021-02. Fourier Transform Infrared (FTIR) spectroscopy was performed, along with kinetic studies of the sand binding process using the ultrasonic method, complemented by observations of the resulting binder bridges. During the ultrasonic tests, the influence of the applied sand matrix on the value of the obtained wave velocities (CL) and on the changes in the degree of sand hardening (Sx) during binding was determined. Additionally, the kinetics of the hardening process were determined based on dCL/dt and dSx/dt. All experiments were conducted on an ultrasonic testing station equipped with a temperature-controlled chamber, maintaining an ambient temperature of 20 °C throughout the measurements. Care was taken to ensure that the temperature of the molding sand after mixing all components remained at approximately 20 ± 1 °C.
Model Tests of the Optimal Location of a New Solution for the Module for Blowing Liquid Steel with an Inert Gas
This article presents the results of research aimed at determining the optimal location in the bottom of a steel ladle for an module for inert gas injection during the argon process. A physical water model of the ladle was used, constructed according to the principles of similarity, at a linear scale of 1:3.4 relative to the industrial device. This model represents a real object with a capacity of 65 Mg of liquid steel. Two variants of the module's position relative to the base point were adopted for the research, designated at a distance of 0.176 m from the horizontal diameter of the ladle bottom and 0.147 m from the vertical diameter. In variant 1, the longer axis of the module was placed parallel to the horizontal diameter of the ladle bottom, and in variant 2, perpendicular. The research was divided into two stages: quantitative and qualitative. A tracer in form of aqueous KMnO4 solution was used for visualization (qualitative studies), while an aqueous NaCl solution was used to determine the mixing curves (quantitative studies). The minimum mixing time value, determined on the basis of the determined mixing curves, was used as a criterion for assessing the effectiveness of the tested modules in various locations.
Investigation of Fe and Mn Effects on the Fluidity Behavior of A356 Aluminum Alloys
The fluidity behavior of Al–Si casting alloys is strongly influenced by impurity elements and intermetallic phase formation during solidification. In particular, iron (Fe) reduces melt fluidity by forming brittle Fe-rich intermetallics, whereas manganese (Mn) can mitigate this effect by modifying intermetallic morphology. In this study, secondary A356 aluminum alloys were produced with Fe contents of 0.10, 0.15, and 0.20 wt.% and nominal Mn additions of 0.05, 0.10, and 0.20 wt.% to investigate their combined effect on fluidity behavior. Melt quality was assessed using reduced pressure testing and density index measurements to ensure consistent casting conditions. Fluidity tests were conducted using spiral and eight-channel molds with section thicknesses ranging from 0.5 to 8 mm. To enable quantitative comparison across different section geometries, a Fluidity Index (FI) was defined based on section-normalized flow lengths. The results show that increasing Fe content generally reduces fluidity, while Mn additions significantly improve melt flow, with the most pronounced enhancement observed at 0.20 wt.% Mn. Thinner sections were found to be more sensitive to Fe-related flow restriction, whereas wider channels exhibited improved flow behavior. These findings demonstrate that appropriate Mn additions can effectively stabilize fluidity in secondary A356 alloys and provide practical guidelines for alloy control in recycled aluminum casting applications.
Foundry Dust - Alternative Additive for Green Sand Mixtures
Foundry dust is a significant component of the waste produced by the foundry industry worldwide. This waste is generated during mould making, melting, casting and discharging of moulds, where dust particles are released and subsequently captured by filters. Like most foundry waste, foundry dust usually ends up in landfills. However, this method of waste management faces problems related to environmental and economic requirements, especially in view of tightening legislation. It is important to point out that foundry dust contains components that could be reused in the production of foundry mixtures. The aim of this study is to evaluate the possible positive and negative effects of two foundry dust samples on the quality of the green sand mixtures. Basic analyses include the chemical composition of the leachate in aqueous solution and the granulometric composition of the dust particles. Furthermore, the properties of other ingredients for the preparation of green sand mixtures will be characterized. The study serves as a starting point for future research in the reuse of foundry dust in green sand mixtures, thus contributing to the sustainability of industrial processes.
Interface Carbon Content and its Influence on Carburization of Steel in Bimetallic Castings
Modern materials engineering is increasingly moving away from monolithic structures in favor of bimetal components. Layered castings combining steel and cast iron provide an excellent response to the conflicting operational requirements that machine parts must meet. Combining the high ductility and strength of steel with the exceptional abrasion resistance and vibration damping properties of cast iron allows for the creation of components that are both durable and crack-resistant. The key to success in this technology is achieving a permanent diffusion bond at the interface between the two phases, which requires precise control of the thermal and physicochemical parameters of the casting process. This paper presents the impact of the difference in carbon content between the joined layers on diffusion efficiency and, consequently, joint quality.
Tribological Properties of EN-GJL-150 grey Cast Iron Composites Produced Using Porous SiC and Al₂O₃ Inserts
The article presents the tribological properties of a newly developed cast iron–ceramic composite designed for modern braking systems, such as brake discs. The composite matrix consists of grey cast iron with flake graphite (EN-GJL-150), while the reinforcing phase comprises 10% SiC and 10% Al₂O₃ particles applied onto a porous structure. Tribological tests were performed using a pin-on-disc setup, and the results were compared with a standard friction material P50 094, representing PEX-type brake pads. The results indicate that reinforcing the matrix with ceramic particles significantly alters the tribological wear mechanism. Composites EN-GJL-150+SiC and EN-GJL-150+Al₂O₃ showed an almost fivefold reduction in mass loss compared to pure cast iron. In the tested pairings, wear of the friction material was also reduced, suggesting a synergistic improvement in the durability of the entire tribological system. The coefficient of friction for cast iron samples reinforced with SiC and Al2O3 ranged from μ = 0.20–0.30, in contrast to the large variations (μ = 0.16–0.46) observed in cast iron without reinforcing particles. In composites containing porous ceramic inserts, no characteristic running-in period to reach stable friction values was observed. The obtained results of reduced wear of friction components and lower scatter of the coefficient of friction for grey cast iron-based composites are promising. However, further studies are required, mainly for a comprehensive evaluation of other functional properties, including the selection of friction pad material and reduction of environmental dust from wear products, as required by the new European Union directives (e.g., EURO 7 standards).
Impact of the Moulding Parameters on Flowability of Bentonite-Bonded-Green Sand Mould
Compactability of the green sand, water content, and parameters of the moulding machine of the pressing speed, and compaction force have an influence on the sand moulding process. These parameters of the moulding machine and moulding material were examined to determine the appropriate factors to make bentonite-bonded green sand mould have a good flowability around the pattern. In the current work, flowability of the green sand was measured based on non-destructive flowability test using a new sand motion detection sensor flowability measurement during the pressing process of the green sand supports finding the optimal compaction time without wasting of the consumed energy for the compaction process. The results obtained of time-dependent-flowability shows that 26% compactability, and 4.17% water content gives highest flowability during compaction of the green sand by using 36 mm/s of the pressing speed. It was found that flowability of the green sand increases as a result of increasing of speed of the pressing machine.
Thermal Properties of the Foundry Sand Mould Material Bonded with Resol Type Resin
This study presents a comprehensive analysis of the thermophysical properties of a casting mould based on BK 50 quartz sand and a resol-type phenol-formaldehyde resin. The investigation combines classical laboratory measurements using Differential Scanning Calorimetry (DSC) with in-situ temperature field recording inside a foundry mold during the solidification of a copper plate casting. Based on specific heat capacity data and readings from seven thermocouples, temperature-dependent values of thermal diffusivity (a), heat capacity (b), and thermal conductivity (λ) were determined. The results indicate a low thermal conductivity of the tested material and a strong temperature dependence of its thermophysical properties. A significant influence of residual moisture was observed during the initial heat exchange phase, manifesting as disturbances in the heating curves around 100 °C. The adopted methodology enabled a realistic mapping of thermal conditions during solidification and confirmed the stable course of the process. The identified thermophysical coefficients characterize the material and are crucial for providing accurate input parameters in numerical simulations of casting processes. Furthermore, they support the informed selection of molding materials in industrial applications, contributing to more reliable simulation outcomes and improved process design, material selection, and final casting quality. The findings validate the integration of laboratory measurements with in-situ analysis and point to the necessity of further research involving various binders, sand grain size distributions, and elevated pouring temperatures.
Optimization of Rotary Degassing Parameters to Improve Melt Cleanliness and Mechanical Properties in A356 Aluminum Alloy
Melt cleanliness is a critical factor that directly affects the quality of aluminum castings and becomes even more significant in recycling-oriented production, where high scrap utilization is inevitable. Increasing the proportion of scrap intensifies the risk of oxide films, inclusions, and gas porosity in the molten metal; therefore, efficient refining techniques are essential. In this study, the effects of rotary degassing parameters—including rotor speed, rotation time, and gas flow rate—on melt cleanliness of A356 aluminum alloy were systematically investigated. Experimental melts containing 20% primary and 80% scrap aluminum were treated under various degassing conditions using a commercial flux cleaning flux. Characterization was performed through the Reduced Pressure Test (RPT), bifilm index analysis, fluidity measurements, microstructural examinations, and mechanical testing (tensile test and Brinell hardness measurement). The results demonstrated that increasing the rotor speed from 200 rpm to 500 rpm significantly reduced both the density and bifilm indices, indicating a notable improvement in melt cleanliness. Furthermore, higher gas flow rate (10 L/min) and longer rotation time (10 min) provided additional but secondary improvements. Consequently, the optimization of rotary degassing parameters enhanced not only melt quality but also tensile strength and ductility. These findings offer practical insights for optimizing process control in recycling-based aluminum foundries.
The Influence of Casting Technology on the Mechanical Properties and Microstructure of the WE43 Alloy for Medical Applications
Melting and casting technologies were developed for the aluminum-free magnesium alloy WE43, which is a promising candidate for biomedical applications due to its high biocompatibility. The alloy was melted in a steel crucible under a protective high-purity argon atmosphere at approximately 710°C to prevent oxidation. To evaluate the influence of the casting method on the final properties of the material, samples were prepared using three different technologies: from ingots, from castings produced by gravity casting into a steel mold, and from components obtained by high-pressure die-casting using a horizontal cold-chamber machine. The prepared samples were subjected to chemical composition analysis, non-destructive testing, mechanical characterization (hardness and tensile strength), and detailed microstructural evaluation using optical and electron microscopy. The results demonstrated that the alloy exhibited tensile strengths in the range of 100–200 MPa and porosity between 1.0–2.6%, while the microstructure was refined as a result of the applied casting techniques. The aim of this study was to identify the optimal production route to ensure the alloy's highest possible quality and performance of the alloy for biomedical use. Based on a comparative analysis of all the test results, the most suitable form and processing conditions of the WE43 alloy were determined for further development as the matrix material in an innovative, biodegradable magnesium-based biomaterial.
The Effect of Minor Additions of Be on the Microstructure of AlSi5Cu2Mg Alloys
In this work, the effect of minor additions of Be as an alloying element on the structural properties of the low-silicon AlSi5Cu2Mg alloy was investigated. The aim was to implement a non-standard addition to the AlSi5Cu2Mg alloy, which would lead to an improvement in mechanical properties, mainly elongation, carried out crystallization and stabilize intermetallic phases of the preparation. The results show that Be additions in the range of 0.05 wt. %, 0.08 wt. % and 0.12 wt.% in the low-silicon AlSi5Cu2Mg alloy affect crystallization by refining the grain size and affecting the structural integrity of undesirable iron-rich phases. Be acts as a grain refiner in low-silicon AlSi5Cu2Mg alloys, refining α-(Al). Be had a significant effect on the shape, size and morphology of the intermetallic phases. Compact skeletal Fe-based phases were destabilized and fragmented into Chinese-character particles and fine spherical particles. The change contributed to the improvement of mechanical properties and reduced the degradation effect of the Fe plate phases. The refining effect increased with higher Be addition. This refining significantly improved tensile strength (Rm) and elongation (A50), with the strongest effect at 0.12 wt. % Be. The separate melting and the addition of AlBe5 in the liquid state were shown to be effective and correct.
Does an Increase in Iron Content Affect the Shrinkage Porosity of Secondary Al-Si Alloys?
This article attempts to answer the question of which theory of porosity formation in Al-Si alloy castings is correct? The one that suggests shrinkage porosity results from the presence of plate-like β-Al5FeSi phases in the alloy, or the one that porosity is caused by thin, double-layer oxide films? The study was conducted on an AlSi7Mg alloy with an increased content of secondary materials (from 45% to 65%), gravity cast at low pressure (up to 0.15 MPa). It was shown that the main factor that determines the causes of shrinkage porosity in aluminium alloys is the method of delivering the liquid metal to the mould cavity. The microstructure examination results of the gravity-cast AlSi7Mg alloy showed that, with increasing iron content, the quantitative fraction of the β-Al₅FeSi phase increases, and their length grows from approximately 40 μm (at 0.4 wt.% Fe) to about 700 μm (at 0.8 wt.% Fe). Under such conditions, the dominant cause of shrinkage porosity in castings is the b-Fe phase, whose unfavorable morphology blocks the interdendritic alloy flow channels. This results in decreased permeability between dendrites α(Al), and consequently increased casting porosity. In pressure castings, the proportion of β-Fe phases is negligible (length up to approximately 30 μm). Numerous oxides were found in close proximity to shrinkage pores. After solidification of the AlSi7Mg alloy, these air "gaps" constitute pores that are not associated with β-Fe phases. Therefore, it can be concluded that in pressure castings, thin oxide films ("bifilms") are a more significant cause of shrinkage porosity than the β-Fe phases.
Influence of Molding Mixture Composition on TOC and BTEX Emissions
The work deals with the issue of BTEX (benzene, toluene, ethylbenzene, xylenes) and TOC (Total Organic Carbon) emissions arising from molding mixtures due to the decomposition of organic compounds at high temperatures and lack of oxygen. The measurements are focused on the combination of bentonite molding mixture with cold-box cores, which is very often used for casting cast iron castings, especially in serial and mass production. The number of emissions is controlled by changing the air access to the mold by choosing the grain size of the silica sand and optimizing the mold-metal ratio by changing the height of the molding mixture above the casting. The highest measured TOC value was in the mold made of mixture ŠH32/E/4CB/20, which exceeded the still valid limit of 150 mgC/m3. The TOC values of the other molds were around the limit of 50 mgC/m3. The amount of BTEX emissions correlates with TOC measurements, where up to 3 times more emissions were released from the molds prepared of ŠH32/E/4CB/20. The idea behind the measurements is find a simple and easily applicable methods for foundry industry leading to a reduction in TOC and BTEX emissions. The results so far show that by optimizing the composition of the molding mixture and adjusting the ratio between the molding mixture and the metal, the amount of these emissions can be effectively reduced. The influence of the type of used silica sand, especially its squareness, origin and the ability of different types of bentonites to absorb the resulting harmful compounds and thus reduce emissions released from the molds remains an open question.
Evaluation of Mechanical Properties of GTAW Hardfacing Intended for the Repair of Permanent Foundry Mold Components
The repair of permanent steel foundry moulds is a critical industrial challenge driven by the need to minimize production costs and extend tool life. Gas Tungsten Arc Welding (GTAW) hardfacing offers a cost-effective restoration method, yet the impact of substrate dilution on the functional performance of high-alloyed layers remains insufficiently quantified. This study presents a unique evaluation of the synergy between the dilution rate and the tribological stability of the iron-based UTP-A 696 alloy deposited on an S355JR substrate. Three experimental samples with varying numbers of layers were prepared to analyze the transition from the fusion line to the pure hardfacing zone. The level of dilution was determined using spectral analysis and energy-dispersive X-ray spectroscopy (EDX). The results, supported by statistical processing, demonstrate that while the first layer suffers from significant mixing, the subsequent layers achieve a stable martensitic microstructure with a high density of complex carbides. A key finding of this research is the identification of a critical threshold for maintaining a stable coefficient of friction (0.753), providing a practical methodology for optimizing repair cycles in foundry environments. The study concludes that achieving a balance between dilution and hardness (up to 64 HRC) is paramount for the operational integrity of renovated mold components.
Optimization of Hybrid Bentonite for Mechanical Properties of Green Sand Mould
Aim – As green sand moulding is the cheapest, fastest, and most commonly used method for metal casting process this research aims to optimize the hybrid bentonite for the mechanical properties of green sand mould which leads to a better-quality of casting and reduction in rework. Materials – For the experiments green sand was prepared by mixing reclaimed sand, garcolap powder, hybrid bentonite and water. Hybrid bentonite is a mixture of bentonite (pure sodium bentonite containing more than 75% montmorillonite) and clay (bentonite clay having 40-55% montmorillonite). Experiments/Methodology/Approach – Experimental results were optimized using Minitab software version 21 to find out values of bentonite, garcolap powder and water to be kept constant for experiments to optimize hybrid bentonite. In this research work mechanical properties of green sand like compactibility, permeability, mould hardness (MH), green compressive strength (GCS) and moisture content were measured for the experiments performed on specimen prepared from green sand in accordance with the IS: 1918-1966. Findings – Experiments performed to optimize hybrid bentonite suggests best combine values of process parameters for hybrid bentonite with 85/15 ratio. Research limitations/Implications – Hybrid bentonite composition optimized in this research can be applied to prepare hybrid bentonite for other casting industries only if the chemical composition of bentonite is approximately same as used in current work. If chemical composition of bentonite gets changed then researcher has to apply same methodology to find new composition of hybrid bentonite for their green sand moulding process.
Effect of Superheat Temperature on Hardness and Impact Energy of AlMg1SiCu Cast-alloy
This study aimed to evaluate the effect of superheat temperature variation on Vickers hardness and Charpy impact energy of AlMg1SiCu cast-alloy. The material used was Al 6061 metal alloy (re-melt) in the form of rectangular bars. This alloy was melted in an electric furnace and cast in a metal mold. The five superheat of liquidus temperatures applied were +50°C, +100°C, +150°C, +200°C, and +250°C. To reduce thermal shock due to the temperature difference between molten metal and the mold, the mold was heated before the casting process. Subsequently, samples for hardness and impact tests were prepared using machine cutting and tested according to ASTM standards. The results showed an increase in hardness and impact energy along with high superheat temperature. This showed that superheat temperature had a significant effect on the mechanical properties of AlMg1SiCu cast-alloy, with higher values contributing to increased hardness and toughness of the material.
Research Progress on the Effect of Cooling Rate on the Precipitation of Non-metallic Inclusions in Steel
This review summarizes recent experimental, thermodynamic, and kinetic studies on how cooling rate affects the precipitation and evolution of non-metallic inclusions in steel, with emphasis on oxides, sulfides, and nitrides. Across the reported literature, increasing cooling rate generally increases inclusion number density while refining particle size by shortening growth time and suppressing late-stage diffusion and compositional redistribution. For oxide inclusions, rapid cooling promotes the formation of finer and more dispersed particles, whereas slow cooling favors particle coarsening and the evolution of multi-component inclusions such as oxide-sulfide composites. For sulfide inclusions, especially MnS, higher cooling rates usually reduce average size and suppress the formation of continuous interdendritic or chain-like morphologies, while slower cooling promotes coarsening, interconnection, and composite formation with oxides or CaS-containing shells. For nitride inclusions such as TiN and AlN, rapid cooling tends to increase the population of fine particles but restricts coarsening and grain-boundary network formation. Studies show that, with increasing cooling rate, the average size of oxide inclusions in pipeline steel decreases markedly, and the mean TiN size can decrease from about 10 micrometers to about 3 micrometers. Overall, cooling rate is a key process variable because it simultaneously influences nucleation, growth, segregation, phase transformation, and interfacial reactions during solidification and subsequent cooling. A clearer understanding of these effects can support inclusion engineering, process optimization, steel cleanliness control, and property improvement in industrial steels.
The Influence of the Thermodynamic Equilibrium Model of the Fe-M-C-N System on the Results of Calculations of Carbonitride Precipitation Kinetics
The microalloying elements such as: Ti, Nb, V are added into steels to control their microstructure and mechanical properties. High chemical affinity of these elements for interstitials (N, C) results in precipitation of binary compounds, nitrides and carbides and products of their mutual solubility product – carbonitrides. Influence of carbonitrides on the microstructure and mechanical properties depends on their basic stereological parameters: volume fraction, VVvv, and their size, rr. Proper analysis of the carbonitride precipitation kinetics and the influence of the steel chemical composition on the parameters of M(C,N) carbonitride precipitates formed under isothermal conditions and on the precipitation hardening effect is important in the process of modelling the microstructure and mechanical properties of microalloyed steels. The paper presents a comparison of two thermodynamic equilibrium models: Adrian and Maugis-Gouné, and their impact on the results of calculations of carbonitride precipitation kinetics.
Solidification of Massive Nodular Cast Iron Mill Rolls in Combined Metal–Sand Molds
At crystallization of castings the various defects such as shrinkage cavities, shrinkage depressions and others are often formed. The purpose of the present work is to experimentally investigate the crystallization process of a massive rolling mill of high-strength cast iron, and to adapt the mathematical model. In the result of the experimental study of the 2160 kg mill roll casting solidification process, the mathematical model was adapted from a reference roll to enable its application to rolls of other sizes. Simulation of ≈7500 kg rolls solidification in combined metal–sand molds revealed the position of the isosolidus fronts, formation of a shrinkage depression on the hot top surface after electroslag heating, and the volume of shrinkage cavities in the hot spot. The volume of the depression was used as the first approximation to estimate the volume of the shrinkage cavity in the hot spot of the casting. This method enables the calculation of chill mass and the elimination of hot spots and shrinkage depressions without the need for complex measuring equipment.
New 3003 Based Aluminium Alloy for Automotive Industry
It is estimated that up to 30 % of all human related green-house gases (GHGs) emissions in developed countries come from transport. Aluminium alloys are very popular materials for achieving weight reduction in new vehicles, thereby reducing fuel consumption and associated GHGs emissions. Unfortunately, the aluminium industry itself has a very harsh environmental impact. In order to achieve an overall GHGs emissions reduction, new aluminium alloys suitable for recycling need to be designed. The aim of this work is to present new fully recycled aluminium alloy for automotive applications based on modified composition of EN AW-3003 which allows higher impurity content. The microstructure and the mechanical properties of the new material are studied by optical microscopy and tensile tests in as-cast temper and as a 2.5 mm thick sheet in various heat treatment conditions. The results are compared with standard EN AW 3003 alloy and show that the properties of both alloys are relatively close.
Effect of Bainitisation Temperature on Phase Transformation Kinetics in Silicon-Alloyed Cast Steels
This study investigates the effect of bainitisation temperature on the kinetics of phase transformation and the resulting microstructure in cast steels with two different silicon levels (0.87 wt.% and 2.06 wt.%). Cast steels were produced by induction melting and centrifugal casting. The remaining alloying elements were kept similar between alloys. A combined approach of JmatPRO simulations, high-resolution dilatometry, XRD, SEM, and Vickers hardness testing was used to characterise transformation temperatures, phase fractions, morphology and mechanical response. Results show that silicon exerts both thermodynamic and kinetic influences: thermodynamically, it tends to favour ferrite in equilibrium phase fields, while kinetically, it suppresses carbide precipitation during bainitic transformation, promoting carbon partitioning to austenite and thus increasing the fraction of retained austenite after austempering. Compared to the lower-Si alloy, the higher-Si alloy exhibits a bainitic transformation shifted to lower temperatures, higher hardness in fully transformed and quenched conditions, and larger retained-austenite fractions after isothermal bainitisation. Proper selection of bainitisation temperature in high-silicon cast steels enables favourable mechanical properties while retaining silicon-related benefits such as improved oxidation resistance and tempering stability.
The Influence of Heat Treatment on the Corrosion Resistance of Weld Deposits on Steel X8CrNi25-21
This work focuses on a comprehensive study of the influence of weld overlays on X8CrNi25-21 austenitic stainless steel, a material known for its excellent heat and corrosion resistance. The main objective is to investigate the mechanisms of sensitization induction in the material due to the thermal cycles associated with the overlay process. Subsequently, the study analyzes the possibility of reversing this undesirable condition through controlled heat treatment. The experimental part includes a detailed characterization of the material before and after welding, as well as after the application of reverse heat treatment. Key parameters evaluated include material hardness and microstructural changes. It is hypothesized that applying a specifically designed heat treatment regimen will allow for the dissolution of precipitated chromium carbides (primarily Cr23C6) at grain boundaries, thereby restoring the local chromium concentration and improving corrosion resistance. The service life of a material plays a very important role in practice, mainly from an economic and, in this case, safety perspective. The aim of this work was to analyze the effect of 70% atmospheric humidity on X8CrNi25-21 steel welds, which are used in roof constructions. The aim of the work was to analyze the effect of heat treatment on intergranular corrosion in steel welds X8CrNi25-21, which is used as a roof structure.
High-Purity Copper Recovery from Fine Enameled Wires by Controlled Pyrolysis and Property Evaluation
*]:pointer-events-auto R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-[calc(var(--header-height)+min(200px,max(70px,20svh)))]" dir="auto" data-turn-id="request-6a4b9991-224c-83eb-8190-d0e833776905-13" data-turn-id-container="request-6a4b9991-224c-83eb-8190-d0e833776905-13" data-testid="conversation-turn-256" data-turn="assistant"> The recovery of high-purity copper from used fine enameled wires without loss of mass is a valuable solution for foundries. Although this waste is widely available on the market, it remains undervalued due to significant losses during processing. This study presents an effective thermal recycling method for fine enameled copper wires, designed to remove insulation while preserving the metal's metallurgical properties. Pyrolysis was performed between 450°C and 900°C with constant holding phases, followed by remelting in an induction furnace. Chemical, microstructural (SEM and optical), and electrical analyses identified an optimal temperature of 550°C with a holding time of 82 minutes, based on a well-defined thermal sequence. At this temperature, the enamel is completely decomposed, resulting in copper with 99.5% purity before melting and a recovery rate exceeding 99%. After melting, the 8 mm wire produced had a uniform microstructure and an average conductivity of 97.2% IACS, aligning with industrial standards for wire drawing (electrical applications). In contrast, direct melting of untreated wires caused inclusions, metal losses, and reduced conductivity. The proposed process, which is simple and cost-effective, offers an efficient way to recycle this type of waste and supports the circular economy.