Mold Casting Research Articles

Additive Technologies for Production and Repair of Agricultural Equipment

Introduction. The article raises the issue of repairing modern agricultural machinery. Because of increasing the complexity of the design of machine components, there is a problem of failure of their parts. Manufacturers often do not sell these parts separately that makes it impossible to repair failed machine components. In this case, the purchase of a machine component assembly is required. The problem of supplying service parts is very significant. This significantly increases the repair time that negatively affects the agricultural production profitability due to the extremely limited time for farming operations. A solution to the issue of supplying service parts, reducing the cost of repairs and breakdown time is in the independent production of parts using additive technologies.Aim of the Study. The study is aimed at examining the complete cycle of additive manufacturing using 3D scanning, 3D printing, and vacuum casting in silicone molds to reduce the renovation cost of technical equipment for agriculture.Materials and Methods. Additive manufacturing is a technology for creating three-dimensional objects through layer-by-layer building. In this technology, there are used a computer, 3D printer and 3D scanner. The 3D printer, based on the CAM model data, distributes the material on the construction surface, and through various sintering or mel­ting technologies, gives the shape of the future part. A 3D scanner allows creating a three-dimensional model of the finished product for subsequent improvement, modernization, expansion or simply copying with the possibility of subsequent printing. In addition to the production of parts by 3D printing, vacuum casting of polymers into silicone molds is very popular. This technology can use prototypes printed on a 3D printer or obtained using a classical production method as a master model.Results. To study the state of the issue, we have used research materials of the Design and Rapid Prototyping Technology Center “RAPID-PRO” of the National Research N.P. Ogarev Mordovia State University. Analyzing the statistical data over the past 5 years, we have concluded that the demand for all types of work in the additive manufacturing cycle has recently become urgent. There is a trend of increasing demand for 3D scanning and reverse engineering services.Discussion and Conclusion. The use of additive technologies makes it possible to produce quickly the parts of any complexity and therefore to reduce significantly the time for scientific research and design. At scientific, educational and industrial institutions special sectors, there should be created areas and centers, equipped for working in the field of additive manufacturing. However, the lack of trained personnel, the lack of basic know­ledge about additive technologies and skills in using the equipment significantly reduces the speed of implementation of these technologies at the repair facilities of the agricultural sector and requires retraining and training of specialists.

Effect of Submerged Entry Nozzle Design on Fluid Flow Dynamics Inside the Thin Slab Caster Mold

Effect of Submerged Entry Nozzle Design on Fluid Flow Dynamics Inside the Thin Slab Caster Mold

Effect of Surface Coatings on the Service Life of Unimax Casting Tool Steel

The tool steel materials are expensive this is the reason why the lifetime increase is a goal of the production technology. The tool life is determined by the various complex mechanical, thermal, chemical, and tribological properties. Tools properties depend on the chemical composition and their microstructure. The microstructure depends on the chemical composition, the production process, the heat treatment and surface treatment technologies. The goal of this research was to increase the service lifetime of the casting mould tool. It was prepared and investigated four kinds of test specimens. The first kind of specimen was made from conventional steel (W302). It was made an austenitization (1020°C) and was cooled with 9 bar nitrogen gas to 40°C and kept for 6 minutes. The quenching was followed with three times tempering processes (570°C, 580°C, 560°C) in 2 bar N2 gas. The second kind of test specimen was made from Unimax electro-slag remelted steel (ESR). It was made an austenitization (1020°C) and was cooled with 9 bar nitrogen gas to 40°C and kept for 6 minutes. After quenching the process continues with three times tempering (610°C, 620°C, 600°C). The third kind of test specimen Unimax a electro-slag remelted steel (ESR), to which firstly an austenitization (1020°C) was made, quenched in nitrogen gas with 9bar and then cooled in liquid nitrogen till minus 150°C. After cryogenic treatment, the process continues with three times tempering (610°C, 620°C, 600°C). The fourth kind of specimen was made by the same process as the second and after it a PVD coating process was made to coat the surface by a TiBN layer. It investigated the hardness and wear resistance of all heat-treated and surface-coated steel specimens. The comparative wear resistance testing was investigated by a ball cratering tester. The rank of the tested specimen was the next: the lowest wear resistance measured in the case of the heat-treated W302, the middle in the case of cryogenic heat-treated Unimax and the highest wear resistance earned in the case of the PVD-coated Unimax. The results of the investigations proved that the Unimax tool steel service lifetime can increase better than the conventional tool steel by heat treatment and surface treatment. The practice certified that the surface-treated Unimax tools' service lifetime is much longer than the conventional ones.

Digitalizing Material Knowledge: A Practical Framework for Ontology-Driven Knowledge Graphs in Process Chains

This paper proposes a robust methodology for integrating process-specific data and domain expert knowledge into linked knowledge graphs. These graphs utilize an ontology that provides a standardized vocabulary for material science and facilitates the creation of semantic models for various processes along the digital process chain. A generic template for structuring processes is proposed, simplifying subsequent data retrieval. The templates of specific processes are designed collaboratively by domain and ontology experts, aided by a proposed interview template that bridges the knowledge gap. Following the digitalization of material data through semantic modeling, machine-readable data with contextual metadata is stored in a graph database, which can be efficiently queried using the SPARQL language, enabling seamless integration into data pipelines. To demonstrate this approach, a knowledge graph is developed to represent the process chain of AlSi10Mg objects manufactured via permanent mold casting, capturing their complete history from the initial manufacturing step to final non-destructive testing and mechanical characterization. This methodology enhances data interoperability and accessibility while providing context-rich data for training AI models, potentially accelerating new knowledge discovery in material science.

Alumina Crucibles from Free Dispersant Suspensions: A Useful Labware to form Advanced Powders for Radiation Dosimetry

Background: Powder technology provides conditions to control particle-particle interactions that drive the formation of final-component/material, which also includes the crystalline structure, microstructure and features. Alumina (Al2O3) is the most studied ceramic based material due to its useful properties, disposal, competitive price, and wide technological applicability. This work aims to produce alumina crucibles with controlled size and shape from free dispensant suspensions. These crucibles will be used as containers for the synthesis of new materials for radiation dosimetry. Methods: The Al2O3 powders were characterized by XRD, SEM, PCS, and EPR. The stability of alumina particles in aqueous solvent was evaluated by zeta potential determination as a function of pH. Alumina suspensions with 30 vol% were shaped by slip casting in plaster molds, followed by sintering at 1600oC for 2 h in an air atmosphere. Alumina based crucibles were characterized by SEM and XRD. Results: ɑ-Al2O3 powders exhibited a mean particle diameter size (d50) of 983nm. Besides, the stability of particles in aqueous solvent was achieved at a range of pH from 2.0-6.0, and from 8.5-11.0. EPR spectra revealed two resonance peaks P1 and P2, with g-values of 2.0004 and 2.0022, respectively. The as-sintered ɑ-alumina based crucibles presented uniform shape and controlled size with no apparent defects. In addition, the final microstructure driven by solid-state sintering revealed a dense surface and uniform distribution of grains. Conclusion: The ɑ-Al2O3 crucibles obtained by slip casting of free dispensant alumina suspensions, followed by sintering, exhibited mechanical strength, and controlled shape and size. These crucibles will be useful labwares for the synthesis of new materials for radiation dosimetry.

Optimizing the Material Extrusion Process for Investment Casting Mould Production

This study investigates the optimization of the Material Extrusion (MEX) process for producing polylactic acid (PLA) patterns used in investment casting moulds, specifically targeting the casting of non-ferrous alloys such as brass. Key MEX process parameters—layer thickness, wall thickness, infill density, and post-processing with dichloromethane vapour for surface enhancement—were systematically analyzed for their impact on mould quality. Results indicate that an optimized combination of MEX parameters yields moulds with high dimensional accuracy, low surface roughness, and minimal pattern residue within the mould cavity. These optimized moulds were subsequently used in brass casting, with the final cast parts evaluated for dimensional precision and surface finish. The study concludes that PLA patterns manufactured via optimized MEX parameters provide a precise, cost-effective, and easy-to-implement solution for industry applications. Additionally, this process is environmentally friendly and presents clear advantages over other pattern-making methods, offering a sustainable alternative for producing complex metal parts with reduced environmental impact. The findings underscore the significant role of post-processing in enhancing mould quality and, consequently, the quality of the cast parts.

Oldest menispermaceous endocarp fossil from the Deccan Intertrappean Beds of Central India and its biogeographic implications

Palaeosinomenium Chandler, a fossil genus of the Menispermaceae, has a characteristic endocarp morphology that is easily identified in the fossil floras. Palaeosinomenium was widely distributed in the Paleogene, based on reports from North America, Europe, and East Asia, but was not known from South Asia. Here, we recognize a new fossil-species, Palaeosinomenium indicum sp. nov., based on an endocarp mold and locule cast from the latest Maastrichtian (late Cretaceous)-earliest Danian (early Paleocene) sediments (c. 66–65 Ma old) of the Deccan Intertrappean beds of the Umariya site in Madhya Pradesh, Central India. This new species is characterized by a horseshoe-shaped endocarp with a broad-rounded dorsal margin, almost equal limbs, and a nearly straight ventral margin. It has one dorsal ridge, shallowly concave lateral faces, and a pair of c-shaped lateral ridges one on each side of the plane of bisymmetry, and about 19 radially aligned dorsal ribs. This new finding is the earliest fossil fruit evidence of Menispermaceae indicating an early occurrence of the family in Gondwana.

Research on frozen sand mold casting technology for complex thin-walled aluminum alloy castings

With the growing emphasis on environmental sustainability and the modernization of the manufacturing sector, the pursuit of eco-friendly practices within the foundry industry has become a critical objective. This paper proposes an innovative solution for environmentally friendly casting: the digital frozen sand mold casting technology. To evaluate its effectiveness, this study analyzed complex thin-walled grid rudder aluminum alloy castings. A comparative analysis was conducted between the binder jetting 3D printing and frozen sand mold (sand mold milling) casting processes. By utilizing Anycasting software, the research explored the filling and solidification processes of ZL101 grid rudder castings under varying mold conditions, aiming to predict the distribution and severity of shrinkage defects. Validation of this approach indicated a machining error of ±0.25 mm for frozen sand molds. The dimensional accuracy of the grid rudder castings achieved a casting tolerance grade of 9 (CT9), and the direct recovery rate of used sand exceeded 98 %, thus positioning this method as a viable alternative to 3D-printed resin sand. Additionally, the study assessed the economic feasibility of frozen sand mold casting technology in terms of resource consumption and production efficiency. The research findings hold significant relevance, offering valuable insights and guidance for traditional casting enterprises seeking to adopt sustainable development practices through the application of leveraging frozen sand casting technology.

Effect of homogenization treatment on microstructure and properties of novel Al-Mg-Zn-Sc-Zr alloys with different Mg/Zn ratios

This study investigated the effect of homogenization treatment on microstructure and properties of Al-Mg-Zn-Sc-Zr alloys with different Mg/Zn ratios using optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), electron backscatter diffraction (EBSD), transmission electron microscope (TEM), hardness, and conductivity tests. The results show severe dendrite segregation in Al-Mg-Zn-Sc-Zr ingots produced by water-cooled copper mold casting, with the as-cast microstructure mainly composed of an α-Al matrix, non-equilibrium T-Mg32(Al,Zn)49 phase, and a small amount of coarse primary Al3(Sc, Zr) phase. As Mg/Zn ratio decreases, the volume fraction of T-phase increases from 4.92 % to 5.41 %, and the grain size increases from 15.41 μm to 20.43 μm. DSC curves show the first endothermic peak at 468–475 °C, corresponding to the melting temperature of non-equilibrium second phase, setting the homogenization temperature to 460 °C. As homogenization time increases, non-equilibrium phase gradually dissolves. When Mg/Zn ratio is 1.71, the over-burning phenomenon occurs at 24 h; With the reduction of Mg/Zn ratio to 1.33, the over-burning occurred at 16 h. Two-stage homogenization significantly increased the amount of the second phase Al3(Sc, Zr) and refined grain size. After two-stage homogenization, the hardness and conductivity of the studied alloys with Mg/Zn ratio of 1.77 and 1.31 reach maximum values of 135.53HV and 144.22HV, and the conductivity is 30.10 % IACS and 28.71 % IACS, respectively.

Exploration of the causes of abnormal mold level fluctuation in thin slab continuous casting mold

Abnormal fluctuations in the mold can easily lead to slag entrainment during the thin slab continuous casting process. It is difficult to guarantee the uniform growth of the shell solidification of the slab. The quality of the slab is seriously affected. In this study, the data on thin slab mold level fluctuation were collected from a complete casting sequence of low-carbon steel in a Chinese plant. The discrete wavelet transform (DWT) method is used to decompose the mold level fluctuation and different process parameters. The frequency composition of abnormal fluctuations was clarified, and the causes of the abnormal fluctuations were revealed. The results show that the frequency ranges of abnormal fluctuations are concentrated in 0.3125-0.625 Hz and 0.625-1.25 Hz, and the low set mold level is where the maximum amplitude occurs. Within the time-frequency range, changes in parameters such as electromagnetic braking, mold oscillation, casting speed, stopper rod, and tundish weight cannot be completely matched to abnormal fluctuations collected by the eddy current sensor (ECS). It was found that the abnormal fluctuations in the ECS were that its equipment was disturbed through the analysis of the fluctuations collected by the radioactive source detection (RSD). The degree of disturbance is related to the height of the set mold level. The maximum fluctuation difference exceeded 6 mm between different collection methods when the set mold level was low. In this plant, the position of the ECS is to avoid the area of violent fluctuations of the surface molten steel and be moved appropriately towards the submerged entry nozzle (SEN) to reduce disturbance. When the current ECS position is unchanged, the mold level is set at approximately 305-309 mm, and the casting speed is matched to 4.8 m/min, which minimizes the disturbance with the ECS measurement.

Development, implementation, and evaluation of a 3D‐printed high‐fidelity pediatric mannequin with expected hard‐to‐intubate airway

AbstractClinical simulation is fundamental for the healthcare staff to learn and enhance their procedural skills without causing harm to the patients. Despite its importance, in literature appears a deficiency of pediatric pathological mannequins, especially those simulating difficult airway management due to the obstruction of the passage of tubes, fiberscopes, or catheters. Given the importance of simulating complex scenarios in the medical staff's training, the authors decided to realize a modular high‐fidelity pathological mannequin with nasal access using reverse engineering and additive manufacturing techniques within T3Ddy, a joint laboratory between Meyer Children's Hospital of Florence and the Department of Industrial Engineering of the University of Florence. The mannequin is developed from diagnostic images of a significant 30‐month‐old polymalformative patient also affected by Pierre‐Robin syndrome modifying the tracheobronchial tree to reproduce an abnormal status. Rigid parts and silicone cast molds are manufactured using 3D‐printed ABS/ASA while platinum‐cure‐silicones are used for the soft ones. Meyer's anesthesiologists collaborated to the realization providing feedback during design and production. The device is evaluated with a 5‐point Likert scale questionnaire and results in a useful tool for the training of procedural skills related to difficult intubation as its realism, anatomical geometry, and tactic feedback are positively evaluated.

Design a Gating System for an Aluminum Cast Three-Way Pipe in Sand Casting

The study of aluminum casting work with market demand in the metal casting industry, designing a gating system in aluminum casting using a three-way pipe-shaped sand mold workpiece as a basic shape template in metal casting, namely a flat-face core box with a core. The gating system has a metal inlet with design variables including the pouring height, pouring basin cross-sectional area, rest basin cross-sectional area, running system cross-sectional area and inlet cross-sectional area. From the studying and designing, actual casting experiments were conducted and simulation behavior was analyzed using Cast-Designer software to make decisions and find appropriate design approaches from analyzing simulation results including liquid metal filling time, molten metal flow behavior, metal solidification time and shrinkage porosity formation of the workpiece. The results of the casting experiment and behavior simulation were able to cast the pipe workpiece which is a flat-face core box mold. The analysis results from the software can be used for actual pouring, where the fully cast mold successfully produced a complete workpiece. This can be a guideline for future improvements to reduce the shrinkage of actual cast workpieces.

The Influence of Polymer Impregnating Materials on Structural Strengthening of 3D Printed Sand Molds Produced by Binder Jetting Method.

Additive manufacturing offers great potential for various industrial solutions; in particular, the binder jetting method enables the production of components from various materials, including sand molds for casting. This work presents the results of an extensive set of experiments aimed at enhancing the structural strengthening of 3D-printed sand molds. Structural strengthening was achieved by impregnating the sand-printed structures with two polymer materials: epoxy resin and silicone varnish. Impregnation was performed with variable parameters, such as temperature, pressure, and time. Structural strengthening using polymers was investigated by analyzing the flexural strength and impact resistance of the impregnated products and comparing these obtained values with the reference material in terms of impregnation parameters and the polymer used. Microstructural observations and an analysis of the pore filling were also performed. This approach allowed for a full assessment of the influence of processing parameters and the type of polymer used for impregnation on the properties of sand-printed structures, which allowed for identifying the most optimal method to be used to strengthen the sand molds for casting the components for electrical devices. As a direct proof of concept, it was shown that impregnation with polymeric materials could effectively strengthen the sand mold, increasing its flexural strength and impact resistance by over 20 times and 5 times, respectively. A full-scale mold was printed using binder jetting, impregnated with epoxy resin at 65 °C, and used to successfully fabricate a fully functional electrification device.

Application of Digital Twins in Designing Safety Systems for Robotic Stations

The aim of this paper is to present examples and original solutions related to the application of the digital twin concept in designing safety systems for robotic stations. This paper includes a review of publications on robot safety systems and digital twins. Based on this review, it was concluded that further work in this area is justified. This paper demonstrates the use of a digital model of a robotic casting mold preparation station to design safety components for an industrial cell. A key element of this paper is the presentation of developed algorithms and their applications in building digital twins of existing robotic stations. By characterizing advanced safety systems used in robotic stations, an example of using a digital twin of a robotic station to create safety zones and so-called restricted zones for the robot was developed. As part of the research conducted, a real, comprehensive example of creating safety zones based on the robot’s TCP paths was carried out.

Application of X-Ray Computed Tomography to Identify Defects in Lost Wax Ceramic Moulds for Precision Casting of Turbine Blades.

This article presents the results of testing the suitability of X-ray computed tomography for the quality control of the casting moulds used for producing turbine blades. The research was focused on the analysis of cross-sectional images, spatial models and the porosity of moulds using a Phoenix L 450 microtomograph. The research material consisted of samples from three mixtures of ceramic materials and binders intended for producing casting moulds using the lost wax method. Various configurations of filling materials (Molochite and quartz flours) and binder (Remasol, Ludox PX 30 and hydrolysed ethyl silicate) mixtures were considered. X-ray computed tomography enabled the detection of a number of defects in the ceramic mass related to the distribution of mass components, porosity concentration and defects resulting from the specificity of the mould production. It was found that casting mould quality control on cross-sectional tomographic images is faster and as accurate as the analysis of three-dimensional models and allows for the detection of a whole range of ceramic defects, but the usefulness of the images is greatest only when the cross-sections are taken at an appropriate angle relative to the object being examined.

Corrosion and wear mechanisms of rare earth (Gd, Sc, Y)-doped Zr-based amorphous alloys

Rare-earth elements have been utilized in the design and development of new amorphous alloys to improve the corrosion and wear resistance of Zr-based amorphous alloys. In this study, a rare-earth doped Zr-based amorphous alloy (Zr-BMG(RE)) was prepared by the copper mold casting method, which was investigated by corrosion and wear experiments. The results show that Zr-BMG(RE) has a completely amorphous structure, and the doping of rare earths Gd and Y raises the crystallization transition temperature of the amorphous. The addition of rare earth elements Gd and Sc increases the microhardness of Zr-based amorphous alloys, while rare earth element Y causes a slight decrease in microhardness. Gd and Sc will make Zr-based amorphous materials corrosion current density increases, the material pitting and localized corrosion, acid corrosion resistance is reduced. Y doping improves the self-corrosion potential of Zr-based amorphous alloys, reduces the corrosion current density, the surface passivation film is the densest, and the degree of charge transfer on the metal surface is the most difficult, Zr-BMG(Y) has a better corrosion resistance compared with other alloy materials. Zr-BMG(Gd) has the smallest friction rate (1.72 × 10−7mm3N−1mm−1), and the wear rates of the rare earth doped Zr-based amorphous alloys are all smaller than that of Zr-BMG, and the main loss mechanism of Zr-based amorphous alloys is the interaction of adhesive wear, abrasive wear, oxidative wear and fatigue wear. The mechanism of corrosion and wear resistance of rare earth to Zr-based amorphous alloys is discussed, which provides a new idea for the design of amorphous alloys.

The Making of Roman Lead Ingots. Their Casting by Experiment and the Archaeological Evidence

Casting experiments in Brilon-Hoppecke (North Rhine-Westfalia, Germany) in 2011 and 2012 as well as in 2015 aimed to reconstruct the production of Roman lead ingots with the help of archaeological experiments on the one hand; on the other hand, traces of the moulding process on the Roman lead ingots themselves and the epigraphic evidence were examined to provide further information on the production process. The results of this research, suggest that most of the lead ingots were very likely cast in clay sand moulds which almost completely disintegrated after the ingots had been removed. In a few cases, wood could be verified as the material for the moulds. Finally, all known artefacts associated with the casting of lead ingots have been critically examined and reinterpreted.

Application of crystallization additivity principle in continuous casting mould flux

Application of crystallization additivity principle in continuous casting mould flux

Study on the inverse problem of thin slab continuous casting mold based on fluid-solid coupled heat transfer

The thin slab continuous casting (TSCC) process employs a funnel-shaped mold, introducing increased complexity to both the structure and heat transfer of the mold, as well as the cooling water channels. This paper presents a three-dimensional fluid-solid coupled model for calculating the heat flux in a thin slab mold. The model is calculated and validated based on temperature data collected from molds and cooling water in the plant. The results show that the deviations of the wide face average heat flux and cooling water temperature difference from the measured values are 3.49 % and 1.1 %, respectively, demonstrating good agreement. Moreover, the influence of the thin slab mold geometry on heat transfer is explored. The heat flux values calculated in this model are approximately 13 % lower than those in the simplified model in the upper part of the original funnel area, and 2–7% lower in the lower part. Therefore, this model reflects the heat flux's three-dimensional characteristics of the funnel-shaped mold, offering a novel approach to calculating the heat flux of the thin slab mold.

Numerical simulation study on the mold strength of magnetic mold casting based on a coupled electromagnetic-structural method

Numerical simulation study on the mold strength of magnetic mold casting based on a coupled electromagnetic-structural method