Metal Casting Research Articles

Ultrasonic Melt Processing: Progress, Applications, and Future Directions

Ultrasonic melt processing (UMP) has garnered significant attention from both academic and industrial communities as a promising solution to critical challenges in the metal casting industry. This technique offers a clean, environmentally friendly, and energy-efficient approach to improving melt quality and achieving structural refinement. However, due to the opaque nature of metals, understanding the fundamental mechanisms governing the interactions among ultrasonic bubbles, acoustic streaming, and the melt remains still challenging. This review traces the evolution of UMP research, from its inception in the mid-20th century to recent advancements, with particular emphasis on the application of state-of-the-art synchrotron X-ray imaging and computational modeling. These approaches have been instrumental in unraveling the complex, multiscale dynamics occurring across both temporal and spatial scales. Key findings in various metallic alloy systems are critically reviewed, focusing on new insights into cavitation bubbles, acoustic streaming, and the interactions of growing solid phases in different alloys. Additionally, the review discusses the resulting phenomena, including grain refinement, fragmentation, and the mitigation of solidification defects, in detail. The review concludes by identifying critical research gaps and emerging trends, underscoring the indispensable role of in situ studies and robust theoretical frameworks in advancing UMP. These developments are poised to reshape the future of innovation in materials science and engineering.

Comparative Evaluation of Fracture Resistance and Failure Modes in Endodontically Treated Teeth Restored With Zirconia-Reinforced Lithium Silicate and Cast Metal Alloys: An In Vitro Study

Comparative Evaluation of Fracture Resistance and Failure Modes in Endodontically Treated Teeth Restored With Zirconia-Reinforced Lithium Silicate and Cast Metal Alloys: An In Vitro Study

Studying strategic behaviour of small industrial enterprises in the context of the organizational and industry life cycle concepts

Unlike large corporations whose business patterns have been extensively studied and categorized, there is a lack of research on small business strategies, leaving them largely unexplored. The article explores the strategic behaviour of small industrial enterprises in Russia within the organizational and industry life cycle concept. The research methodology is based on strategic management theory and the concept of the life cycle. The research methods include panel data analysis, the Beta coef f icient calculation, and the matrix method. The information base is the reporting data of 134 small enterprises from industries at different stages of the life cycle: metal casting (growth) and newspaper printing (maturity). Statistics for analysis were obtained from the SPARK Interfax database for the period of 1999–2021. We identified three types of strategic behaviour (‘aggressive’, ‘de fender’, and ‘counterstrategy’) and assessed their prevalence among small enterprises in the two industries under consideration. The results showed that mature small enterprises with an ‘aggressive’ intuitively strategic behaviour are the predominant type of business in a mature industry, while for small enterprises in a growing industry ‘defender’ and ‘counterstrategy’ are the prevalent strategies at all the life cycle stages. This paradox additionally proves the validity of our idea of the intuitively strategic behaviour of small businesses. Our findings contribute to the development of the SME life cycle theory and strategic management, can be used to adjust industry policy and government support measures, and can also be of interest to managers of small enterprises.

Horizontal Magnetic Field Influence on Fluid Flow Across a Variable Thickness Rotating Disk With Stretching and Melting Phenomenon

ABSTRACTAn incompressible steady‐state flow of viscous fluid subjected to a variable thickness rotating surface is examined. The laminar flow stream is also affected by the disk stretching. A horizontal magnetic field is applied along the disk to stabilize the flow dynamics depending on its orientation and strength. The implication of a horizontal magnetic field is also effective in regulating the thermal energy in high‐temperature environments such as turbines and nuclear reactors. The thermal features are also characterized by thermal radiation and melting heating. The melting phenomenon is useful in phase‐change materials for efficient thermal storage and release like polymer molding or metal casting. Similarity transformations that account for the variable thickness of the disk surface are utilized to dimensionalize the flow equations and to obtain a self‐similar solution. The numerical scheme Runge‐Kutta‐Fehlberg (RKF‐45) built‐in package is used for the solution of the normalized flow model. The salient nature of the physical parameters is illustrated in the momentum and thermal fields. The numerical data on skin‐friction coefficient and local Nusselt number at the stretchable surface is also calculated. The graphical results indicate that the flow and temperature profiles are strongly influenced by the physical parameters under consideration. It can be deduced that melting decreases the fluid resistance close to the surface, reducing drag, and in turn increasing flow velocity. The latent energy absorbed during the melting process reduces the effective thermal energy into the fluid that reduces the temperature gradients in the thermal boundary layer flow. The stabilizing effect of the horizontal magnetic field on the flow phenomenon along the radial direction is observed for the angle varying from 0 to 30 degrees. It is seen that the dimensionless radius facilitates the thermal transport phenomenon from the disk surface to the fluid, thus resulting in reduction of the thermal field.

Utilization of Industrial Waste Casting Sands as Sustainable Building Material in Autoclaved Aerated Concrete Products

Autoclaved aerated concrete (AAC) is a building material with low density compared to traditional and structurally lightweight concrete. In addition to being very light, it is frequently preferred in many different areas, especially in external walls, floor slabs, lintels, roof slabs and panel elements of buildings, since it offers good heat and sound insulation. When the AAC production process is evaluated in terms of energy requirement, it has high environmental sensitivity compared to traditional concrete and brick processes. Since environmental sensitivity has become more important today, it was desired to evaluate the waste casting sands (WCS) generated in metal casting companies within the scope of the study. In this study, the usability of WCS as an alternative instead of silica sand used in AAC production was investigated. For this purpose, WCS was provided by 3 different casting companies. The usability potential of WCSs at 30% was examined and the quality of AAC was compared with reference castings. The fineness potentials of WCSs were compared by grinding in a disc mill. First of all, X-ray fluorescence spectrometry (XRF) and grain size analyses were performed on WCSs. 150x150x150 mm3 sized AAC laboratory samples were produced. The produced AAC samples were kept in the oven at 60°C until they set and then cured in an autoclave for approximately 10 hours. After the curing process in the autoclave, analyses such as compressive strength analyses and dry unit weight measurements were performed on the samples, and in addition to these analyses, they were subjected to visual examinations. Mechanical analyses were performed by replacing the WCS, from which positive results were obtained, at 5 different substitution ratios of 5, 10, 15, 20, and 30% by weight. From scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses, it was determined that tobermorite structures were formed. From thermal analyses, it was observed that the thermal stability of the samples produced with WCS was better. When the results were evaluated in general, it was found that up to 30% WCS could be included in the AAC production system. In addition, an increase in compressive strength values occurred. The improvement in compressive strength also showed that WCS could be a good alternative source to silica sand.

A hybrid Genetic Algorithm and Fuzzy Logic approach to ergonomic design of workstations in metal casting operations

A hybrid Genetic Algorithm and Fuzzy Logic approach to ergonomic design of workstations in metal casting operations

MOTORIZED HOSE ROLLING TOOL FOR FIREFIGHTER: DESIGN AND FABRICATION PROCESS

This paper addresses the critical problem of low back pain (LBP) among firefighters, particularly during hose rolling operations. The main objective is to lower the average probability of LBP risks by introducing a motorized hose roller for such activities. The development of this tool is guided by prior studies which included a survey. The design and fabrication processes of the motorized hose roller involved assessing existing patents for novelty, employing Solid Work software for design, using a morphological chart for concept selection, and finalizing fabrication through metal casting and wiring. Based on the experiment that had been conducted, the conventional hose rolling methods recorded an average LBP risk probabilities of 58.22%, while the motorized hose rolling tool method significantly reduced these risks to 17.44%, representing a 40.78% reduction of LBP risks. These findings highlight the effectiveness of motorized hose rolling tool and its potential as a safer alternative to existing methods, offering vital insights for improving occupational health and safety in hose rolling operation. This research further explores the design and fabrication of motorized tools, emphasizing their potential to alleviate the physical loads encountered by firefighters.

Precipitation of Sr-rich and Fe-rich intermetallic compounds in Al alloys

The precipitation of intermetallic compounds (IMCs) in an aluminium alloy Al-7Si-0.4Mg (A356) was studied, making additions of Fe, Sr, and Mg. The experiment avoided metallographic techniques, using a novel experimental approach in which the outside surface of the cast metal was studied. Precipitation of IMCs was observed to occur on the surface of oxide bifilms in suspension in the liquid metal, occasionally as a Sr-rich IMC growth from one side and a Fe-rich IMC growth from the other, corroborating the structure of the bifilm as having two wetted outer sides. The bifilms onto which heavy IMCs had precipitated were observed by nanotomography to sediment rapidly, indicating a potential method of cleaning secondary metals from both bifilms and metals like Fe.

An Overview of Machine Learning Applications in Metal Casting Industries

This paper presents an overview of different machine learning (ML) techniques and algorithms implemented in metal casting industries. ML has made significant contributions to the field of metal casting by improving various aspects of the casting process. In this work, referred quality research papers are divided into two categories. Firstly, work reviewed for the automation in foundry and quality control. Secondly, the raw material melting, material designs and defect predictions in the metal casting. The literature is extensively studied for types of ML models implemented from 2010 to 2023 for the sand-casting application area especially in the prediction of material melting compositions, desired material properties and occurrence of defects along with involvement of advanced foundry technologies.

Impact of Scrap Impurities on AlSi7Cu0.5Mg Alloy Flowability Using Established Testing Methods

In view of the increasing demand for secondary aluminum, which is intended to partially replace the very energy- and resource-intensive primary aluminum production, effective treatment methods can maintain the high quality level of light metal castings. The transition from a linear to a circular economy can result in an accumulation of oxides or carbides in aluminum. Therefore, melt purification is crucial, especially as foundries aim to increase the use of often dirty end-of-life scrap. Nonmetallic inclusions in the melt can impact its flowability and mechanical properties. As the purity of the melt increases, its flow length also tends to increase. Available assessment methods like reduced pressure test or K-mold are capable of ensuring high levels of purity. This study demonstrates the implication of inclusions originating from dirty scrap. An experimental test run deals with various scrap contents in an AlSi7Cu0.5Mg alloy and shows correlations between impurity and performance, expressed by flowability and mechanical properties. These performance indicators have been connected to inclusion and porosity rates. In conclusion, these findings emphasize the need for further extensive research on contaminants in the field of scrap melting and the development of methods for easy-to-handle assessment methods.

Comparison of the Fracture Strength and Fracture Mode of Endodontically Treated Maxillary Incisors Restored with Cast Metal and Glass Fiber Post

Comparison of the Fracture Strength and Fracture Mode of Endodontically Treated Maxillary Incisors Restored with Cast Metal and Glass Fiber Post

PENGUKURAN pH, DISSOLVED OXYGEN (DO), DAN TOTAL DISSOLVED SOLID (TDS) PADA SUNGAI WILAYAH INDUSTRI COR LOGAM KABUPATEN HULU SUNGAI SELATAN

Water is essential for human life, used daily for drinking, cooking, bathing, washing, and various other purposes. The presence of industrial waste can significantly impact the water quality of rivers located in industrial areas. In North Daha District, South Kalimantan, there is a metal casting industry that discharges its waste into a nearby river. Therefore, measuring the water quality of the river is necessary to determine the level of pollution caused by industrial waste. The objective of this study is to obtain parameters from water quality tests, such as pH, dissolved oxygen (DO), and total dissolved solid (TDS), to assess the river's condition before and after metal casting processed. Additionally, the study aims to compare the test results against water quality standards for public consumption. The research method involves direct measurement of river water using a multiparameter water quality testing instrument. The test results before metal casting processed are pH 6,33 – 6,47; DO 1,03 – 2,18 ppm; and TDS 45 – 65 ppm. The test result after casting processed are pH 6,57 – 6,85; DO 6,66 – 13,19 ppm; and TDS 43 – 48 ppm. Comparing from PP RI Number 82 (2001) that the metal casting industry activities have water criterion within the range allowable values. That indicate the industry do not contaminate the river in the industrial area. The river pollution is primarily caused by tidal phenomena, particularly during low tide conditions.

Design and modelling of fastener system on sand core making shell machine

Abstract Sand core making shell have been considered as a system for metal casting. In the molding of molten casting, the shell machine needs to be fasten using bolts and nuts. The concept of the article discusses bolt’s strength using analytical methods and numerical calculations of materials and dimensional variations. The size and load received by the mold on the automatic sand casting machine normally 1000 kPa. Sand casting mold have dimension around 470 × 415 × 550 mm. Thus, the proposed clamped by 4 hardened hexagonal bolts. Our study provides understanding for the design and numerical modelling of fastener system for the mold clamping of metal casting.

The image of Aphrodite in Empedocles

Aphrodite is one of the important deities of the Greek pantheon. But she is not the only one and at first glance does not seem to be the most honoured and powerful. In the Homeric epic and hymns she is presented as a narcissistic, capricious and passion-prone goddess. She is mostly associated with beauty and love charms. It might seem that this was enough for Empedocles to identify her with one of the two active powers – Love. However, in Empedocles' poem the image of Aphrodite is very complex and, in many ways, differs from the traditional view of her. She acts as a god-craftsman, is involved in such activities as metal casting, pottery, and artwork. The main question I will try to answer is the following – can we find the origins of this complex image in the literary and cultural tradition known in Empedocles' time, or did he make a radical turn and invent a new previously unknown idea of the deity?

THE EFFECT OF REPETITIVE METAL CASTING ON THE TENSILE STRENGTH OF DENTURES

Background: Dentures or prostheses function to replace chewing and dental arch structures. Denture plates used in dentistry are made with acrylic resin, metal, or a combination of acrylic and metal. Metals are shiny, opaque chemical substances and good conductors of heat and can be polished. Recycling or reusing used metal is an option in making prostheses because the price of new metal is increasing, and metal recycling is quite effective. Purpose: To determine the effect of repeated metal casting on the strength of the metal frame denture base. Method: The current research is a laboratory study with a tensile test in the form of dumbbells with iso 22674 with a length of 15 ± 1 mm and a diameter of 3 ± 1 mm. This research used 18 CoCr metal samples divided into three groups, namely 100% new metal group (control), 50% new + 50% repeated composition group, and 100% repeated group. Result: The mean strain of the new 100% CoCr metals group was 0.133%, strain mean of the new 50% CoCr + 50% repeated metals group was 0.1%, and the strain of the 100% repeated CoCr metals group was 0.066%. The average modulus of elasticity (MPa) for the new 100% CoCr metals group is 7866, or 711 MPa, the new 50% CoCr + 50% repeat metals group is 7538, or 833 MPa, the 100% CoCr metals group is 6659, or 336 MPa. Conclusion: The new 100% CoCr metal group has a higher average tensile strength value than the 50% new CoCr metal + 50% repeated group, and the lowest is the 100% repeated CoCr metal group.

Rapid hydrogen generation from Al-Si alloy and recovery of the byproducts

The metal hydrolysis reaction is a convenient and user-friendly strategy for obtaining high-purity hydrogen on-demand. However, removal of the oxide and rapid corrosion of the metal are critical for hydrogen utilization in fuel cell. In this work, commercial Al-Si alloy, which is widely used in metal casting, are used as a raw material to generate high-purity hydrogen. Our results indicate that hydrogen evolution and Al corrosion are influenced by NaOH concentration, elevated temperature from exothermic reaction of Al or Si with OH–, decreased particle size of Al and the Al/Si micro-galvanic cell. And the maximum hydrogen generation rate is 116.4 mL (0.4 g)−1 min−1 for Al-10Si. This reaction consumes OH– ions from NaOH following addition of the first two batches, and then OH– ions derived from Al(OH)−4 or Al(OH)3.The hydrogen generated is transferred to a fuel cell; a stable current of ca. 1 A and voltage of about 0.25 V are obtained for Al-10Si during continuous hydrogen input. The by-product of pure Al(OH)3 and Si can be recovered separately. This investigation of Al-Si alloys as hydrogen generation materials may provide guidance for the exploration of other Si-based materials.

DEVELOPMENT OF AUTOMATED CONTROL SYSTEM AND REGISTRATION OF METAL IN CONTINUOUS CASTING

Context. Modern industrial enterprises face challenges that require introduction of latest technologies to improve efficiency and competitiveness. In metallurgy, one of key stages is continuous casting, where quality of products and economic performance of enterprise depend on accuracy and efficiency of process control. Products made using continuous casting technology are widely used in various industries due to their high mechanical properties, structural uniformity and cost-effectiveness. The development of automated metal management and registration system is becoming not only relevant, but also necessary to ensure stable and efficient production. The problem of improving quality of metal products has always been one of most important tasks in steel industry. Imperfect technological processes, human error and equipment malfunctions can lead to defects in finished metal products. This, in turn, affects final characteristics of products, their durability and reliability. To date, available sources have not yet found complete solution to this problem. Therefore, it is necessary to formulate problem and develop algorithm for operation of automated system for controlling and registering metal in continuous casting. Objective. The goal of work is to develop automated metal management and registration system to improve quality of metal products. Method. To achieve this goal, parametric model was proposed, which is formalized on basis of set theory. The model takes into account key parameters of continuous casting process: material characteristics, structural features of crystallizer, casting modes, metal level in crystallizer, and position of shot stopper. Results. The problem was formulated and key parameters were determined, which are taken into account in system’s algorithm, which made it possible to develop system for controlling parameters of continuous casting to solve problem of improving quality of metal products. Conclusions. To improve quality of metal products and stability of casting process, parametric model was created that is comprehensive, allows optimization of key parameters and ensures accuracy of process control by integrating not only modes of product formation, but also takes into account specific properties of source material (chemical composition of material grade, etc.) and design features of casting plant. Algorithm for automated control system has been developed that takes into account relationships between certain key parameters and ensures optimal control of casting process. Based on proposed complex parametric model and algorithm, automated control and metal registration system was created. The focus of work is on quality and efficiency of metal management and registration in continuous casting, based on modern methods of computer science and engineering. A comprehensive experimental comparison of developed system with commercial analogs in real production conditions was carried out, which allowed us to objectively assess its efficiency and reliability.

Tribological investigation of new self-fluxing nickel alloys for high temperature application: the effect of silicon distribution on glaze layer formation

The objective of this study is to investigate the tribological performance of new nickel-based self-fluxing alloys for replacing cobalt-based alloys in aircraft components. Two new NiCrSiFeB alloys, manufactured by gravity casting and laser metal deposition processes, having different microstructures, are submitted to fretting loadings and tested at temperatures ranging from ambient to 650 °C. Their wear behavior is compared to a reference Stellite 6 cobalt- based alloy. Although the two NiCrSiFeB alloys have the same chemical composition, the alloy having a coarse microstructure rich in silicates was able to form a protective glaze layer at high temperature as Stellite 6. On the other hand, the alloy having a fine microstructure underwent severe adhesive wear. This highlights the crucial effect of the microstructure and the silicon distribution in activating the formation of a protective glaze layer at high temperatures.

Development of geometry-driven quantitative prediction for shrinkage porosity in T-junction of steel sand castings

Shrinkage porosity poses a significant challenge in metal casting processes, impacting both productivity and energy efficiency, especially when dealing with components that are not accepted or reprocessed. Addressing this issue requires proactive measures, and predictive techniques play a crucial role in minimizing its occurrence. Among these methods, the Criterion Function stands out as a valuable empirical model extensively explored in the literature. By intricately linking solidification processes to the development of shrinkage porosity, the Criterion Function leverages key process parameters, including thermal gradient, molten metal velocity during solidification, and cooling rate, to offer predictive insights into the location and presence of porosity. However, a criterion function is needed that also considers the effect of geometric variations as well as the size of the defect (shrinkage porosity). In this study, a casting with three T-joints was taken as a benchmark shape to develop a geometry-based quantitative prediction model for plain carbon steel castings. Real experimental results were combined with solidification simulation results to produce reliable data, which were then used to extrapolate the results. The developed quantitative prediction model, which includes the effect of geometric changes, has been validated and proven effective in predicting shrinkage porosity.

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.