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Fluidity tests of 99.9%Al and 99.7%Al were conducted using a die casting machine equipped with a spiral die with a channel gap of 0.5 mm. The effects of die temperature and plunger speed on the fluidity were investigated. To clarify the flow length for these alloys, ADC12 and Al-X%Fe (X ≤ 1.1) were also cast. A 1.0 mm channel gap was also used to compare the fluidity in a wider gap. The fluidity of 99.9%Al and 99.7%Al at a die temperature of 30 °C and a plunger speed of 0.2 m/s was superior to that at 150 °C and 0.8 m/s when the channel gap was 0.5 mm, and similar results were found for ADC12 and Al-X%Fe. When the die temperature was 30 °C, the fluidity of 99.9%Al and 99.7%Al decreased as the plunger speed increased when the channel gap was 0.5 mm, and similar results were also found for ADC12 and Al-X%Fe. These results did not align with conventional expectations. A discussion of the results based on the peeling and re-melting of the solidified layer was provided. [ABSTRACT FROM AUTHOR]

In order to effectively reduce energy consumption and increase range mile, new energy vehicles represented by Tesla have greatly aroused the application of integrated magnesium (Mg) alloy die casting technology in automobiles. Previously, the application of Mg alloys in automobiles, especially in automotive cockpit components, is quite extensive, while it has almost disappeared for a period of time due to its relatively high cost, causing a certain degree of information loss in the application technology of Mg alloy parts in automobiles. The rapid development of automotive technology has led to a higher requirement for the automotive components compared with those traditional one. Therefore, whatever the components themselves, or the Mg alloy materials and die casting process have to face an increasing challenge, needing to be upgraded. In addition, owing to its high integration characteristics, the application of Mg alloy die casting technology in large-sized and thin-walled automotive parts has inherent advantages and needs to be expanded urgently. Indeed, it necessitates exploring advance Mg alloys and new product structures and optimizing die casting processes. This article summarizes and analyzes the development status of thin-walled and large-sized die casting Mg alloy parts in passenger car cockpit and corresponding material selection methods, die casting processes as well as mold design techniques. Furthermore, this work will aid researchers in establishing a comprehensive understanding of the manufacture of thin-walled and large-sized die casting Mg alloy parts in automobile cockpit. It will also assist them in developing new Mg alloys with improved comprehensive performance and new processes to meet the high requirements for die casting automotive components. [ABSTRACT FROM AUTHOR]

Copyright of FME Transactions is the property of University of Belgrade, Faculty of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study systematically analyzed the effect of design conditions on filling behavior and product characteristics when forming thin plates of magnesium alloy (AZ91D) of 0.5 mm or less using the die casting method. As a research method, a casting analysis simulation program was used to predict filling and solidification behavior under various process conditions. The molten metal injection temperature (610~670 °C), mold temperature (160~220 °C), and cooling water temperature (10~55 °C) were selected as key variables, and an analysis was performed for a total of five conditions. A simulation was conducted to analyze the charging speed distribution, location of oxides and bubbles, and solidification pattern. As a result of the study, the flow of molten metal in the low and high-speed sections of the plunger, uniformity of product thickness, and supply conditions of the molten metal were confirmed to be major factors. It is important to manage the molten metal injection temperature at an appropriate level to minimize product defects. Based on these conditions, a prototype was manufactured, the microstructure was observed, and a fine and uniform grain structure was observed in most areas. In mechanical property evaluation, superior physical properties were secured compared to existing bulk materials. [ABSTRACT FROM AUTHOR]

Against the backdrop of climate policy goals and the EU's aim for a resource-efficient economy, the foundry industry must rethink product range, energy consumption, and production technologies. Light metal casting, which is performed through processes like gravity die casting and high-pressure die casting, requires effective thermal management, which is crucial for optimising mould filling, solidification, cycle times, and part quality. Against this background, this study presents the development and characterisation of a cooling system that completely dispenses with energy-intensive heating/cooling devices. The system is based on a mask shape combined with internal spray cooling. This paper shows the simulation workflow for developing the mould mask and the design of the cooling system and compares the performance with conventional temperature control using channels. In the tests, an 82% higher cooling rate was achieved with Cool-Spray than with conventional temperature control, which was approx. 2.5 mm below the cavity surface. In addition to the more dynamic temperature control, the potential for process control was utilised, and the component quality of the test part was significantly improved compared to conventional temperature control. [ABSTRACT FROM AUTHOR]

The die-casting process of ADC12 aluminum alloy right crankcase cover was simulated based on AnyCasting software, and the influence of pouring temperature, initial mold temperature and injection speed on the filling and solidification process of ADC12 right crankcase cover casting was explored by orthogonal experiment method. The optimal process parameters were obtained through optimization, and the die-casting mold was designed. The program was verified in production. The results show that the porosity and shrinkage of the right crankcase cover are mainly concentrated in the thick wall part. The sequence of process parameters that affect the residual melt modulus is pouring temperature, initial mold temperature, and injection speed; The best combination of process parameters: pouring temperature is ∼680 °C, initial mold temperature is ∼200 °C, injection speed is ∼5 m/s. By analyzing the filling process and temperature field simulation results, the casting structure, mold structure and cooling system were optimized, and the process plan was improved. The production verification was carried out according to the optimized process plan. The casting quality is good and has no obvious defects, which meets the actual production needs.

Die casting has many advantages, such as high precision, mass production, and excellent recyclability. However, gas defects in the product have become a problem. One countermeasure to this problem is to design the injection input of the plunger appropriately. Recently, CFD has been used to design plunger injection inputs, and by combining with optimization techniques, auto-design of plunger injection inputs has been possible. However, CFD is difficult to apply because of the high cost of CFD resources, the need to resource IT engineers, and the time required for its auto-design. Therefore, we propose a new injection input design method based on an algebraic approach, enabling anyone to design a plunger injection input that prevents gas defects with ease and at a low cost. Simulation and experimental results verified the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The demand for lightweight and cost-effective heat sinks is increasing. A typical method for economically manufacturing complex-shape heat sinks is die casting. To reduce the weight of the die-cast heat sinks, thinning the fins and base is common practice. We experimented with casting heat sinks using Al-25%Si in a conventional die casting machine with the aim of economically producing thinner fins and bases. Compared with the aluminum alloy used in conventional die casting, Al-25%Si has superior fluidity, which is proven to be very useful for reducing the thickness of the fins and base. As a result, we successfully reduced the heat sink weight using Al-25%Si and a conventional die casting machine. To investigate the properties of the produced Al-25%Si thin fin heat sink, we compared the effects of fin thickness, fin height, number of fins, and base thickness on heat dissipation and weight reduction. Additionally, we compared the weight and heat dissipation properties with those of a commercial heat sink and found that our Al-25%Si heat sink maintains the same heat dissipation performance but for 35% lower weight. [ABSTRACT FROM AUTHOR]

This study investigates various processing approaches, interface characteristics, and mechanical properties of an aluminum (Al) matrix composite reinforced with additively manufactured (AM) 316L stainless-steel (SS) lattice. The AM-316L-SS lattice, boasting a 30 % infill density, was fabricated using the laser powder bed fusion technique. The Al-matrix was integrated with the AM-316L-SS reinforcement through experimentation involving pre-stirring of the molten Al under pressurized and unpressurized die-casting conditions. A well-bonded interface, with cohesive regions, was obtained in the pre-stirred structures. In contrast, regions of decohesion were displayed in cast structures without pre-stirring, leading to the presence of pores and the manifestation of imperfect bond interfaces. Compression tests conducted on the sound composite demonstrated enhanced mechanical properties, with a compressive strength of approximately 163 MPa, significantly higher than that of the pure Al-matrix (approximately 80 MPa). Localized interface cracking was initiated by stress gradients and plastic deformation, leading to microcrack propagation into the Al-matrix.

Purpose: This study aims to elucidate the machining properties of low-cost expanded clay-reinforced syntactic foams by using different neural network models for the first time in the literature. The main goal of this endeavor is to create a casting machining-neural network modeling flow-line for real-time foam manufacturing in the industry. Design/methodology/approach: Samples were manufactured via an industry-based die-casting technology. For the slot milling tests performed with different cutting speeds, depth of cut and lubrication conditions, a 3-axis computer numerical control (CNC) machine was used and the force data were collected through a digital dynamometer. These signals were used as input parameters in neural network modelings. Findings: Among the algorithms, the scaled-conjugated-gradient (SCG) methodology was the weakest average results, whereas the Levenberg–Marquard (LM) approach was highly successful in foreseeing the cutting forces. As for the input variables, an increase in the depth of cut entailed the cutting forces, and this circumstance was more obvious at the higher cutting speeds. Research limitations/implications: The effect of milling parameters on the cutting forces of low-cost clay-filled metallic syntactics was examined, and the correct detection of these impacts is considerably prominent in this paper. On the other side, tool life and wear analyses can be studied in future investigations. Practical implications: It was indicated that the milling forces of the clay-added AA7075 syntactic foams, depending on the cutting parameters, can be anticipated through artificial neural network modeling. Social implications: It is hoped that analyzing the influence of the cutting parameters using neural network models on the slot milling forces of metallic syntactic foams (MSFs) will be notably useful for research and development (R&D) researchers and design engineers. Originality/value: This work is the first investigation that focuses on the estimation of slot milling forces of the expanded clay-added AA7075 syntactic foams by using different artificial neural network modeling approaches. [ABSTRACT FROM AUTHOR]

Conventional cooling channels used in die casting molds exhibit significant drawbacks, resulting in extended cooling times for cast parts. Issues such as the formation of dirt, limescale, and corrosion substantially diminish the thermal efficiency of these channels, leading to challenges in achieving uniform cooling and potential quality issues. In response to these challenges, this study proposes Topology Optimization as a novel approach. It involves designing cooling structures through Topology Optimization to replace traditional cooling channels, incorporating both Discrete and Gaussian boundary conditions to optimize thermal efficiency. Additionally, Structural Topology Optimization is employed to ensure structural integrity, preventing deformation or yielding under high loads during the die casting process. Numerical analysis revealed superior thermal performance compared to conventional channels, particularly when subjected to Discrete and Gaussian boundary conditions. Furthermore, the application of the latter establishes conformal cooling and minimizes temperature gradients in the casting, reducing casting defects such as shrinkage porosity. These findings highlight the efficacy of Topology Optimization in addressing the challenges of traditional cooling methods, with wide-ranging implications for manufacturing processes utilizing permanent molds for shaping materials. [ABSTRACT FROM AUTHOR]

Using 3D scanning, coordinate measuring machine, and roughness measurements we evaluated and compared zinc alloy castings produced in conventionally and additively manufactured shaped mould parts. Tests were conducted on castings from new shaped parts and subsequently after approximately every 100,000 shots. Castings from conventional parts had higher dimensional stability, but both types showed decreasing dimensional deviations over time. Castings from new additively manufactured parts had higher roughness initially, but this improved with use. Overall, there were no significant issues, and the benefits of additive-shaped parts prevailed. However, more testing is needed for a final recommendation for use in real operating conditions, requiring hundreds of thousands more shots. [ABSTRACT FROM AUTHOR]

Fluidity tests of 99.9%Al and 99.7%Al were conducted using a die casting machine equipped with a spiral die with a channel gap of 0.5 mm. The effects of die temperature and plunger speed on the fluidity were investigated. To clarify the flow length for these alloys, ADC12 and Al-X%Fe (X ≤ 1.1) were also cast. A 1.0 mm channel gap was also used to compare the fluidity in a wider gap. The fluidity of 99.9%Al and 99.7%Al at a die temperature of 30 °C and a plunger speed of 0.2 m/s was superior to that at 150 °C and 0.8 m/s when the channel gap was 0.5 mm, and similar results were found for ADC12 and Al-X%Fe. When the die temperature was 30 °C, the fluidity of 99.9%Al and 99.7%Al decreased as the plunger speed increased when the channel gap was 0.5 mm, and similar results were also found for ADC12 and Al-X%Fe. These results did not align with conventional expectations. A discussion of the results based on the peeling and re-melting of the solidified layer was provided.

The die casting industry plays a vital role in the manufacturing sector and imagining our life without die casting sector is now next to impossible. In the last 2 decades, one more such technology is revolutionizing manufacturing and prototyping, that is 3D printing. 3D printing is much easier and involves fewer processes in comparison to die casting. This can make it a potential alternative to die casting in the future. Die casting and 3D printing, both in their own way, are unique and have different use cases. It is important to see what both of these technologies will look like in future and how they will revolutionize the manufacturing sector. Feasibility, Industry size, productivity and accuracy of both of these processes will also play a very important role in influencing the market. This paper compares both the technologies with help of a case study of producing 100000 “Frying pans” using both of them and analyzes Feasibility, Industry size, productivity and accuracy to prove monopolized supremacy of die casting over 3D printing. There are various ways in which 3D printing can evolve as a competition to Die casting industry. This paper at the end suggests some solutions to counter the challenges faced by 3D printing technology in order to evolve in Indian Markets. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) preform reinforced magnesium (Mg) matrix composites were fabricated by the infiltration of matrix material into a SiC ceramic preform by a cold chamber high-pressure die casting (HPDC) process. All steps of the composite fabrication process are explained, and surface characterizations related to the wear properties of fabricated materials were realized. Wear tests were conducted using a ball-on-disc wear testing device at room temperature under dry sliding conditions. Specific wear rates were calculated using the disk wear loss, which was determined by measuring the wear track width. Wear surfaces were examined using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS). The results show us that the wear resistance of composites improved and that the most effective wear mechanism is scuffing, which is a type of abrasive wear. In addition, a remarkable increase in surface properties was confirmed using hardness measurements and atomic force microscopy (AFM) investigations. [ABSTRACT FROM AUTHOR]

Non-heat-treated Al–Mg-based die casting alloys have been developed for the structural parts of automobiles. In previous studies, alloy compositions with at least 1.0%Si have been proposed to reduce the hot tearing susceptibility (HTS). On the other hand, the increase in the Si content reduces the ductility. For some automotive body structures, Al–Mg alloy die castings with Si content exceeding 1.0% should not have the required ductility. This study aims to develop an Al–Mg alloy with both high ductility and low HTS by investigating the following three characteristics of an Al–4.5Mg–1.0Mn alloy with 0.2%Si added: (1) additional elements to reduce the HTS, (2) the associated mechanical properties (requirements for the automotive company: 0.2% proof stress ≥ 140 MPa and fracture elongation ≥ 15%), and (3) the mechanism of decreasing the HTS. It was revealed that the co-addition of 0.025%Sr, 0.08%Ti, and 0.016%B reduced the HTS when the hydrogen content of the melt was 0.5–1.0 mL/100 g Al. Furthermore, the 0.2% proof stress and fracture elongation of a lower link arm produced via HPDC with the above composition were found to achieve the requirements. It was also indicated that the mechanism of decrease in the HTS by the Sr addition should result from the decrease in the thermal tensile load due to the formation of hydrogen porosity at a lower solid fraction than that without Sr. It is suggested that when 0.025%Sr, 0.08%Ti, and 0.016%B are added to the Al–4.5Mg–1.0Mn–0.2Si alloy, non-heat-treated automotive structural parts with both high ductility and low HTS will be obtained by high-pressure die casting. [ABSTRACT FROM AUTHOR]

In today's manufacturing industries, hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and anti-pollution. At this point, aluminum syntactic foams (ASFs) are new-generation engineering composites and come into the upfront as a problem-solver. Owing to their features like low density, sufficient elongation, and perfect energy absorption ability, these advanced foams have been considerably seductive for many industrial sectors nowadays. In this study, an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay (PEC). Micro evaluations (optical and FESEM) reveal that there is a homogenous particle distribution in the foam samples, and inspections are compatible with the other ASF studies. Additionally, T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive responses. Attained results show that PEC particles can be an alternative to expensive hollow spheres used in the previous works. Besides, a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength. [ABSTRACT FROM AUTHOR]

The result of the development of additive manufacturing (AM) methods is the increasing use of the selective laser melting (SLM) method as a technique for producing tooling for injection moulds and die casting pressure moulds from maraging steel powders. The mould components are subjected to varying thermo-mechanical loads during these operations. This paper presents a numerical model that is used to predict the fatigue life of a material that is loaded with a time-varying temperature field according to the classic and modified Coffin test. Using a computational model, the temperature changes in the resistance-heated specimen and the stress and strain fields that are caused by this phenomenon were determined. Using three different multiaxial fatigue criteria, the fatigue life of SLM steel was determined. Numerical calculations were verified using experimental thermal fatigue tests on 1.2709 SLM steel that was aged at 490 °C as well as via metallographic tests. The numerical model was used to predict the durability of the same steel aged at 540 °C. The effect of specimen clamping conditions on the fatigue life of SLM steel was determined numerically. The value of the decrease in strength of SLM steel as a result of the increasing number of cycles of temperature changes was determined experimentally; a great influence of ageing temperature on fatigue life was found. Changes in the structure of steel occurring during cyclic changes in temperature are presented. [ABSTRACT FROM AUTHOR]

During high-pressure die casting, a significant amount of heat is dissipated via the liquid-cooled channels in the die. The jet cooler, also known as the die insert or bubbler, is one of the most commonly used cooling methods. Nowadays, foundries casting engineered products rely on numerical simulations using commercial software to determine cooling efficiency, which requires precise input data. However, the literature lacks sufficient investigations to describe the spatial distribution of the heat transfer coefficient in the jet cooler. In this study, we propose a solver using the open-source CFD package OpenFOAM and free library for nonlinear optimization NLopt for the inverse heat conduction problem that returns the desired distribution of the heat transfer coefficient. The experimental temperature measurements using multiple thermocouples are considered the input data. The robustness, efficiency, and accuracy of the model are rigorously tested and confirmed. Additionally, temperature measurements of the real jet cooler are presented. [ABSTRACT FROM AUTHOR]

The structural characteristics of the car shift tower cover were analyzed, and the pouring system and overflow system were designed according to the empirical formula.The numerical simulation based on Anycasting software shows that the metal liquid flow and solidification rate of the initial process are not smooth.According to the simulation results, the shape of the runner and the number of the gate were modified, and the point cold water pipe was set at the position where the defects might occur to optimize the process.The numerical simulation of the optimized process scheme shows that the filling process is stable and there is no liquid spatter, and good quality die casting is obtained through actual production.

Against the backdrop of climate policy goals and the EU’s aim for a resource-efficient economy, the foundry industry must rethink product range, energy consumption, and production technologies. Light metal casting, which is performed through processes like gravity die casting and high-pressure die casting, requires effective thermal management, which is crucial for optimising mould filling, solidification, cycle times, and part quality. Against this background, this study presents the development and characterisation of a cooling system that completely dispenses with energy-intensive heating/cooling devices. The system is based on a mask shape combined with internal spray cooling. This paper shows the simulation workflow for developing the mould mask and the design of the cooling system and compares the performance with conventional temperature control using channels. In the tests, an 82% higher cooling rate was achieved with Cool-Spray than with conventional temperature control, which was approx. 2.5 mm below the cavity surface. In addition to the more dynamic temperature control, the potential for process control was utilised, and the component quality of the test part was significantly improved compared to conventional temperature control.

This study systematically analyzed the effect of design conditions on filling behavior and product characteristics when forming thin plates of magnesium alloy (AZ91D) of 0.5 mm or less using the die casting method. As a research method, a casting analysis simulation program was used to predict filling and solidification behavior under various process conditions. The molten metal injection temperature (610~670 °C), mold temperature (160~220 °C), and cooling water temperature (10~55 °C) were selected as key variables, and an analysis was performed for a total of five conditions. A simulation was conducted to analyze the charging speed distribution, location of oxides and bubbles, and solidification pattern. As a result of the study, the flow of molten metal in the low and high-speed sections of the plunger, uniformity of product thickness, and supply conditions of the molten metal were confirmed to be major factors. It is important to manage the molten metal injection temperature at an appropriate level to minimize product defects. Based on these conditions, a prototype was manufactured, the microstructure was observed, and a fine and uniform grain structure was observed in most areas. In mechanical property evaluation, superior physical properties were secured compared to existing bulk materials.

Purpose: This paper was to determine the effect of different manganese addition contents from 0.2 to 1.0 wt.% on the microstructure, HB hardness and selected mechanical properties (UTS; YS; EL) of AlSi10MnMg alloy with increased iron content (about 1.0 wt.%). The proportion of iron in the studied alloy is so high because approx. 50% of the charge came from secondary materials. Design/methodology/approach: Chemical composition tests were performed using a Foundry Master Compact 8 emission spectrometer. Static tensile testing at ambient temperature was carried out according to PN-EN ISO 6892-1 on an Instron 3382 using a 20:1 ratio and a constant tensile speed of 5 mm/min-1. Tensile strength (UTS), conventional yield strength (YS), and per cent elongation after rupture of a proportional sample (EL) were determined from this test. Brinell hardness measurement was performed on a Zwick ZHF1, with a loading force of 250 N, with a 5 mm diameter ball for 35 s. Ten measurements were taken, discarding the two outliers, and the arithmetic mean was calculated from the remaining measurements. Metallographic studies were conducted on a MeF-2 Reichert light microscope. X-ray microanalysis studies were carried out on a Hitachi S-3400 scanning microscope coupled to an EDS Voyager X-ray spectrometer equipped with an SE secondary and BSE backscattered electron detector. Chemical composition analysis was performed by energy dispersive X-ray microanalysis (EDS) using a Thermo Noran detector. Findings: Increased iron content in aluminium-silicon alloys is a major concern. It causes a significant reduction in the mechanical properties of the materials. This is due, among other things, to the increasing scarcity of primary materials (high cost and environmentally unjustifiable) versus the increasing share of recycled materials. Based on the study, AlSi10MnMg(Fe) alloys obtained under pressure with higher iron content (about 1% wt.), the optimal value of manganese addition is about 0.58% wt. Practical implications: This research has shown that it is possible to use recycled Al-Si materials. The article presents one way to reduce the negative impact of iron addition to aluminium alloys as a result of reusing this type of material. Originality/value: The article presents the effect of manganese addition on the selected aluminium alloy. It was determined that the addition of manganese in the amount of 0.58% wt. causes a significant reduction in the negative effect of iron phases. The article is intended not only for the academic community but also for specialists in the foundry industry. [ABSTRACT FROM AUTHOR]

Copyright of Automobile Technology & Material is the property of Automobile Technology & Material Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The demand for lightweight and cost-effective heat sinks is increasing. A typical method for economically manufacturing complex-shape heat sinks is die casting. To reduce the weight of the die-cast heat sinks, thinning the fins and base is common practice. We experimented with casting heat sinks using Al-25%Si in a conventional die casting machine with the aim of economically producing thinner fins and bases. Compared with the aluminum alloy used in conventional die casting, Al-25%Si has superior fluidity, which is proven to be very useful for reducing the thickness of the fins and base. As a result, we successfully reduced the heat sink weight using Al-25%Si and a conventional die casting machine. To investigate the properties of the produced Al-25%Si thin fin heat sink, we compared the effects of fin thickness, fin height, number of fins, and base thickness on heat dissipation and weight reduction. Additionally, we compared the weight and heat dissipation properties with those of a commercial heat sink and found that our Al-25%Si heat sink maintains the same heat dissipation performance but for 35% lower weight.

Using 3D scanning, coordinate measuring machine, and roughness measurements we evaluated and compared zinc alloy castings produced in conventionally and additively manufactured shaped mould parts. Tests were conducted on castings from new shaped parts and subsequently after approximately every 100,000 shots. Castings from conventional parts had higher dimensional stability, but both types showed decreasing dimensional deviations over time. Castings from new additively manufactured parts had higher roughness initially, but this improved with use. Overall, there were no significant issues, and the benefits of additive-shaped parts prevailed. However, more testing is needed for a final recommendation for use in real operating conditions, requiring hundreds of thousands more shots.

The research conducted in the paper highlights the importance of pressure or holding pressure in the mold cavity as a critical production parameter in the high-pressure die casting process for Al-Si alloys. The experiments revealed a direct correlation between the pressure or holding pressure in the mold cavity and the mechanical properties of the castings, including ultimate tensile strength, percentage share of porosity, and the structure of the alloys. The results of the experiments showed that increasing the pressure or holding pressure in the mold cavity led to an increase in ultimate tensile strength and a reduction in the porosity of the castings. The higher pressure or holding pressure also resulted in the elimination of pores in the casting, which further improved its mechanical properties. The increase in ultimate tensile strength and reduction in porosity can be attributed to the better filling of the mold cavity, leading to reduced air entrapment and porosity in the castings. Overall, this paper emphasizes the need for optimizing the technological parameters of the die casting process to ensure the high-quality and efficient production of castings with reduced defects. The results of this study suggest that controlling the pressure or holding pressure in the mold cavity can significantly improve the mechanical properties of the castings, which is essential for achieving the desired quality standards. [ABSTRACT FROM AUTHOR]

The porosity of die-cast aluminum alloys is a determining factor for the quality of the product. In this paper, we studied the porosity of a selected part of a die-cast AlSi9Cu3(Fe) compressor part by computer tomography and metallography. In the case of this part, the achievable resolution by CT, a non-destructive testing method, was 30 μm—this method could not detect smaller cavities. Based on metallographic analysis, the percentage of defects larger than 30 μm ranges from 10 to 30% of the total number of defects, which represents 75–95% of the defective area (area ratio). Impregnation with methacrylate resin (used to seal cavities to prevent leakage) can be detected with UV-illuminated optical microscopic examination on metallographically prepared specimens. As confirmed by scanning electron microscopy, partial filling and partial impregnation can occur in a system of shrinkage cavities. [ABSTRACT FROM AUTHOR]

This paper presents the results of testing the mechanical properties of maraging steel 1.2709 that were obtained by the SLM method under uniaxial and triaxial states of stress. The triaxial state of stress was realised by making circumferential notches in the samples with different radii of rounding. The specimens were subjected to two types of heat treatment, which consisted of ageing at 490 °C and 540 °C for 8 h. The results of the tests that were conducted on the samples were considered as references and compared with the results of the strength tests that were conducted directly on the SLM-made core model. Differences were found between the results of these tests. Based on the experimental results, the relationship between the equivalent strain of the specimen in the bottom of notch εeq and triaxiality factor η was determined. Function εeq = f(η) was proposed as a criterion for the decrease in the plasticity of the material in the area of the pressure mould cooling channel. Using the FEM method, equivalent strain field εeq and triaxiality factor η were determined in the conformal channel cooled core model. Based on the proposed criterion of plasticity loss and the results of numerical calculations, it was shown that the values of equivalent strain εeq and triaxiality factor η in the core that was aged at 490 °C did not meet this criterion. On the other hand, the values of strain εeq and triaxiality factor η did not exceed the safety limit when ageing was carried out at 540 °C. The plasticity loss method presented in this paper assumes that the value of the triaxiality factor in the vicinity of the channel is influenced by the shape, cross-sectional dimensions and trajectory of the channel axis. Using the methodology proposed in this paper, it is possible to determine the value of allowable deformations in the cooling channel zone and to determine whether the heat treatment applied to the SLM steel does not cause an excessive reduction in the plastic properties. [ABSTRACT FROM AUTHOR]

The paper presents the 3-phases milling process simulation of a surface of a polystyrene injection mold, by using CATIA software. The cutting regime parameters are computed and are used, togeth-er with other data, as inputs for the simulation process. On the ba-sis of milling process simulation, the software generates the manu-facturing program for the NC machine tool.

Porous carbon fiber-reinforced Al-Si alloy matrix composites and carbon fiber felt-reinforced Al-Si alloy matrix composites with carbon content of 10 wt.% were prepared by die casting. The dry tribological properties of these two composites and Al-Si alloy were studied using a ball-on-disc rotational tribometer in the rotational speed range of 300 r/min to 1000 r/min, and the wear mechanisms were analyzed in combination with the wear morphology. The results show that the friction coefficient and wear rate of these two composites are lower than the Al-Si alloy at different speeds. With the increase in rotational speed, the friction coefficient of the two composites and Al-Si alloy first increases and then decreases, and the wear rate gradually increases. The wear mechanisms of the two composites and Al-Si alloy change from abrasive wear and adhesive wear to delamination wear, but the node speed of the change in the wear mechanism of the composites to delamination wear is higher, and the wear degree is relatively slight. In addition, the comprehensive tribological properties of carbon fiber felt-reinforced Al-Si alloy matrix composites are better than the porous carbon fiber-reinforced Al-Si alloy matrix composites. [ABSTRACT FROM AUTHOR]

The demand for aluminum in various fields continuously grows, including in the automotive industry. In this industry, aluminum is used as the material for the spare part. Therefore, aluminum with high mechanical properties and low casting defects is required. One of the available alternatives for producing excellent aluminum is through aluminum casting, including die casting. Die casting offers low cost in mass manufacturing of complex shaped components with acceptable casting results. Further, the selection of die-casting parameters and the addition of reinforcing elements can also improve the mechanical properties of aluminum. In this study, we strengthened the Al-Si matrix using High Pressure Die Casting process with particles from snail shell powder (calcium carbonate). Further, this study also explores the mechanical properties and microstructure of the product produced through experiment and optimization. The optimization was adopted to identify the optimum parameter. For the optimization, we used the Taguchi method. Our analysis results suggested that the reinforcing agent from the snail shell powder has the CaO and Ca(OH) _2 phases, with a crystallite size of 106.59 nm. The morphology of the shell powder reinforcing agent showed the presence of agglomeration and interconnected structures, such as skeletons, with average particle size of 0.4 micro. The functional group of the shell powder reinforcing agent showed the OH band during the water absorption by CaO, along with asymmetric C–O with vibration from the carbonate group and Ca–O bound. The most excellent hardness level was identified from T8, with 86.33 HRB and die casting parameters of 0.15% reinforce agents, 750 °C temperature injection, and 50 MPa pressure. Meanwhile, the best tensile strength was found from the T9 sample, with 109,95 MPa and die casting parameters of 0.15% reinforce agents, 800 °C temperature injection, and 60 MPa pressure. Microstructure on the used piston die casting sample with snail shell powder reinforcing agent showed the presence of Al, Si, dendrite, and Al _4 Ca phases. The multiple response analysis on the three factors indicated that the reinforcing agent presented the most significant effects toward the tensile strength and hardness, followed by pressure and temperature injection. Meanwhile, the Taguchi method and ANOVA results showed the optimal parameter die casting was obtained from a combination of 0.15 wt% reinforce agent, 800 °C injection temperature, and 50 MPa pressure. A multiple linear regression mathematical model for tensile strength and hardness was developed from the observed data. In regression model, the value of R ^2 of tensile strength 74.02% and R ^2 of the hardness is 95,18% Thus, the developed model can be effectively used to predict the tensile strength and hardness

To solve the problem of slow solidification of large ingots and the difficulty of eliminating internal shrinkage, a cold steel bar was fed into the molten steel during the solidification process after the completion of casting to affect the solidification process. Different cooling and solidification schemes for 60-ton 16-angle ingots were simulated by the finite element simulation software PROCAST. The simulation results show that the insertion of cold steel rods can shorten the full solidification time of the ingot. It is beneficial to improve the concentrated shrinkage in the central region under the conventional cooling scheme; in terms of the cold steel addition method, the decentralized addition of cold steel is more effective in improving the internal quality of the ingot.

In this study, the time-dependent variation of interfacial heat transfer coefficient (IHTC) for metal molds at different mold temperatures was numerically investigated and the time-dependent interfacial heat transfer mechanisms were determined. For this purpose, IHTC, temperature distribution and heat transfer of aluminum alloy A383 for metal molds were numerically investigated. The interfacial heat transfer coefficient between the mold and the cast part was calculated at a different preheating temperature (493 K, 543 K and 593 K) and the time dependent temperatures of the A383 casting alloy cast at 973 K. The calculated temperatures were used to define the impact of mold temperature on the IHTC. The average IHTC for casting temperatures of 493 K 543 K and 593 K were calculated as 16453 W/m2K, 17441 W/m2K and 18127 W/m2K, respectively. As a result, the IHTC increased with rising up mold temperature. [ABSTRACT FROM AUTHOR]

This paper presents the results of a stress analysis and fatigue life calculation of an HPDC mould core. The calculations were performed using Abaqus and fe-safe software. The numerical model of a core cooled by a conformal channel was based on an existing and working counterpart made of additively manufactured high-strength 1.2709 maraging steel. This study shows that the conformal channel results in a lower average core temperature as compared to the temperature of the same core shape cooled by the conventional method. The course of the stress changes during the mould cycle was also determined. It was found that stresses on the core surface caused the cyclic compression and tension of the material. The necessary strength tests of 1.2709 steel produced by selective laser melting (SLM) within a temperature range of 25 to 550 °C, which were necessary to define the fatigue coefficients by the Seeger approximation method, were also carried out in this study, along with metallographic tests of the fractures of the specimens. Based on the multiaxial fatigue criterion and using the maximum principal deformation hypothesis, the fatigue life of the core and channel surfaces was determined. Based on the calculations, it was shown that crack initiation on the channel surface can occur earlier than on the outer surface of the core. [ABSTRACT FROM AUTHOR]

PIG (Pin-Injection-Gate) die-casting and hot stamping was developed for fabrication of small-sized and thin-walled aluminum alloy parts from the recycled feedstock. The pure aluminum and aluminum alloy granules were utilized as a feedstock model of recycled materials. The measured mass of granules with the estimated weight from 3D-CAD (Computer Aided Design) of products was poured into the PIG-nozzles before injection. After quickly melting by induction heating inside the PIG-nozzle units, the aluminum melts were injected into a die cavity through the PIG-nozzle. No furnaces and no crucibles were needed to store the melt aluminum stock in different from the conventional die-casting system. No clamping mechanism with huge loading machine was also needed to significantly reduce the energy consumption in casting. Much less wastes were yielded in these processes; the ratio of product to waste, or, the materials efficiency was nearly 100%. Nitrogen supersaturation and TiAlN coating were used to protect the PIG-nozzle and the stamping die surfaces from severe adhesion from aluminum melt. The pure aluminum gears and thin-walled mobile phone case were fabricated by this process. X-ray tomography proved that both products had no cavities, pores and shrinkages in their inside. Using the hot stamping unit, the micro-pillared pure aluminum heatsink was fabricated to investigate the holding temperature effect on the aspect ratio of micro-pillar height to width. [ABSTRACT FROM AUTHOR]

At present, the qualified rate of large thin-walled magnesium alloy castings is low. In this study, the effects of mold structure and process parameters were investigated to improve the production qualification rate of castings. The filling process of die castings was simulated by numerical simulation technology to optimize their structure. On the basis of an optimized mold structure, the process parameters of die castings were optimized using a response surface model, and a group of optimal process combinations were obtained: pouring temperature—660 °C; mold preheating temperature—200 °C; injection speed—6.5 m/s. The rationality of the optimized mold structure and process parameters is verified by die-casting experiments. The results show that the optimized mold structure and process parameters can effectively reduce the internal shrinkage cavity casting defects of automotive CCB castings, and effectively improve the production qualification rate of magnesium alloy CCB castings. This research has important guiding significance for the production of large thin-walled magnesium alloy parts. [ABSTRACT FROM AUTHOR]

In this work, the acoustic resonance testing method has been extended by a finite element analysis of the examined component to localize cavities within die casting parts. This novel method aims at a fast and efficient quality inspection which allows hidden cavities in cast components to be detected, which is only possible with X-ray technology at the moment. The promising results show that this method enables the localization of shrinkage cavities. Furthermore, the influence of product scatter has been analyzed regarding the accuracy of the calculated position of artificial defects. [ABSTRACT FROM AUTHOR]