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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.

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.

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 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.

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 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.

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.

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.

Sludge consisting of heavy element phases and oxides is often generated during the casting operation of aluminum (Al) and magnesium (Mg) alloys. With the help of the well-established Sludge Factor (SF) formula, it is relatively easy to control the sludge generation in aluminum alloys. But formation mechanisms and characteristics of sludge in die casting magnesium alloys are still unclear. To ensure the production of high quality die cast components at a low cost, a full understanding of sludge in die casting Mg alloys and its proper control measures need to be developed, since excessive sludge formation affects deleteriously material and operation cost, and casting performance. In the present report, the formation, characteristics and control of Mg die-casting sludge, based on the established knowledge of sludge formation and sludge factor in Al die casting alloys, are reviewed. Previous work on characterization and assessment of sludge in die cast Mg alloys are reviewed. Metallurgical principles for control of sludge in ingot production in association with die casting of Mg alloys are discussed. Rapid assessment of Mg oxide and intermetallics relevant to sludge formation in Mg alloys are highlighted.

High pressure die casting is widely used in metalworking industry. Many of the components and devices directly linked to the hot parts are subjected to severe wear. However, some design updates can enlarge the lifespan of these components and devices. This paper proposes to show how a sustainable maintenance can be obtained by focusing resources on the analysis of the critical problem and its consequent mitigation, whereas they are originated on the human, machine/process or supplier level. Design science research (DSR) was the iterative research methodology chosen to integrate this work. The completion of the objective with the implementation of this new injection subset concept brought extremely beneficial results, such as reduction of its consumption, reduction of acquisition cost and waste generated, and reduction of the intervention time during maintenance operations, as well as increase in equipment availability time.

This manuscript describes a novel method for thermal-stress modelling of a cyclic, permanent die casting process in the commercial software package ABAQUS. The key element in this method is that it updates the casting's geometry according to the deformed die at elevated temperature before filling the die cavity. Using this method, the evolution of gap and/or pressure at the die/casting interface has been predicted. This in turn has allowed for a more fundamental and less empirical description of the evolution in resistance to heat transfer at the interface during a casting cycle. The new methodology has been compared to a previously published methodology, and the comparison shows a noticeable difference between the two approaches in predicting the temperature field in the die and the casting and prediction of areas prone to shrinkage-based porosity. This methodology also predicts the stress distribution in the die in the cyclic steady-state operation, which may be of value in predicting die fatigue life.

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.

This paper presents a re-evaluation of the room temperature mechanical properties and high temperature creep resistance of magnesium die-casting alloy AE44 (Mg-4Al-4RE) in light of the influence of minor Mn addition. It is shown that the Mn-containing AE44 exhibits distinct age hardening response upon direct ageing (T5) due to the precipitation of nanoscale Al-Mn particles, as reported previously in a similar alloy. The T5 ageing leads to a significant improvement in strength with similar ductility. Consequently, the T5-aged AE44 has a remarkably better strength-ductility combination than most Mg die-casting alloys and even the Al die-casting alloy A380. Minor Mn addition is also shown to be critical for the creep resistance of AE44 whereas the influence of the RE constituent is not as significant as previously thought, which reaffirms that precipitation hardening of the α-Mg matrix is more important than grain boundary reinforcement by intermetallic phases for the creep resistance of die-cast Mg alloys. The findings in this work could provide new application perspectives for AE44, particularly in the automotive industry.

The die casting consists of the injection of a liquid metal into a mold cavity, submitting the mechanism to high pressures and subsequent cooling until its solidification. Understanding the operation of injection molding machines, as well as the factors that influence the good process development of these machines, it is important for the mechanical engineering area, in general. Thus, the purpose of this work was to evaluate the closing unit design of a mini-injection moulding machine, using CAD (computer-aided design) and CAE (computer-aided engineering) tools. Through an experimental research, it was possible to observe the behavior of the project, in terms of motion and static analysis. The results have shown an efficient project, regarding the modeling and analysis of movements, however, the tension static analysis points to needed improvements in the model, such as resizing of the articulation bars, in which the tensions were overloaded.

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.

In this study, AZ91 Magnesium alloy is produced by cold chamber high pressure die casting (HPDC) method. Different combinations of the cold chamber HPDC process parameters were selected as; in-mold pressure values of 1000 bar and 1200 bar, the gate speed of 30 m/s and 45 m/s, the casting temperatures of 640°C and 680°C. In addition, the test samples were produced by conventional casting method. Tensile test, hardness test, dry sliding wear test and microstructure analysis of samples were performed. The mechanical properties of the samples produced by the cold chamber HPDC and the conventional casting method were compared. Using these parameters; the casting temperature 680°C, in-mold pressure 1000 bar and the gate speed 30 m/s, the highest tensile strength and the hardness value were obtained. Since the cooling rate in the conventional casting method is slower than that of the cold chamber HPDC method, high mechanical properties are obtained by the formation of a fine-grained structure in the cold chamber HPDC method. In dry sliding wear tests, it was observed that there was a decrease in friction coefficient and less material loss with the increase of hardness values of the sample produced by the cold chamber HPDC method.

The paper reports the results of a physical modelling study of the production of a hypereutectic aluminium alloy to be used for making an alloy vapour source for operation in the magnetron. Within the study, targets from a hypereutectic aluminium-silicon alloy were made in laboratory conditions. Thus obtained material was subjected to heat treatment, porosity analysis, and the assessment of the microstructure and fitness for being used in the magnetron. The process of melting the hypereutectic Al-Si alloy was carried out at the Department of Foundry of the Czestochowa University of Technology. The investigation into the production of the alloy vapour source for the synthesis of the dielectric material from the hypereutectic aluminium alloy has confirmed.

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.

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.

The article presents the requirements for the lubricants used in die casting of non-ferrous alloys and polymer materials. The methodology for conducting research to determine the lubricating properties of materials, as well as the results of studies of the lubricating qualities of materials used in the development of lubricant compositions for die casting of non-ferrous alloys and polymer products are presented. It is shown that the use of the materials researched under study reduces the effort to extract the metal rod from the casting by 4.5–8.9 times. It has been established that it is advisable to use petroleum jelly and fus (by-product of vegetable oil) as materials used to develop the composition of a lubricant for die-casting non-ferrous alloys and polymer products. The lubricity of these materials is, on average, 28.8–51.2% higher than that of other lubricants studied.

Die casting process is widely applied in making Al parts. However, due to high speed of liquid metal flow in the die cavity, gases are prone to be entrapped in the filling, resulting in porosity defects. The X-ray computed tomography scanning technique was used to detect the pores in die-cast ADC12 alloys with different intensification pressures. The three-dimensional features of pores including pore size, number, sphericity have been obtained. The effect of different intensification pressures on two different kinds of pores, namely gas-pores and shrinkage pores, was analyzed. The results show that with increasing the pressure, the pore fractions and quantity gradually decrease. When the pressure increased to 85 MPa, the pores from gas entrapment during the mold filling were compressed, leading to a lower porosity fraction. The pressure cannot affect the pores in the samples with a thin wall (2 mm) due to a great solidification rate.

This paper describes the factors that affect gas content in castings during pressure molding. The possibility of removing air and gases from the cavity of the mold through the ventilation channels in the process of filling it with liquid metal is considered. It is shown that the previously used assumption about the outflow of gases from the mold as through a hole in a thin wall is not correct. The calculations, taking into account the friction factor in narrow ventilation ducts, showed that the required crosssectional area of the ventilation ducts increases 4–6 times with a depth of 0,12 mm. If the obtained value of the cross-sectional area of the ventilation ducts is not possible to realize, at a given depth, it is proposed to use an accompanying vacuum to solve the problem.

In contemporary high-pressure die casting foundries, the mastery of each sequence in the production cycle is more and more important. In the paper, an example of virtual analysis of gearbox casting from Al alloy will be presented. It includes a large variety of parameters, as follows: choosing of appropriate foundry technology, calculation of computer simulation of casting process which takes into account the filling process of cold chamber and filling of cavity, model description of three phases in high-pressure die casting, flow of molten metal, solidification, formation of stress and deformations. Additionally, the optimization of cooling and heating systems will be compared with calculated volume defects, dimensions of castings and their deformations with experimentally obtained values.

This present investigation deals with squeeze casting process in order to produce a component with good mechanical properties such as micro-hardness(VH), tensile strength(Rm), and density(ρ) on LM13 by varying squeeze pressure(P), molten temperature(Tm) and die temperature(Td). Taguchi experimental design L9 orthogonal array was used to determine the signal to noise ratio. The results specified that the squeeze pressure and die preheat temperature are the most influencing parameters for mechanical properties improvement. Genetic algorithm (GA) has been applied to optimize the casting parameters that simultaneously maximize the responses.

Simulation is a very useful tool in the design of the part and process conditions of high-pressure die casting (HPDC), due to the intrinsic complexity of this manufacturing process. Usually, physics-based models solved by finite element or finite volume methods are used, but their main drawback is the long calculation time. In order to apply optimization strategies in the design process or to implement online predictive systems, faster models are required. One solution is the use of surrogate models, also called metamodels or grey-box models. The novelty of the work presented here lies in the development of several metamodels for the HPDC process. These metamodels are based on a gradient boosting regressor technique and derived from a physics-based finite element model. The results show that the developed metamodels are able to predict with high accuracy the secondary dendrite arm spacing (SDAS) of the cast parts and, with good accuracy, the misrun risk and the shrinkage level. Results obtained in the predictions of microporosity and macroporosity, eutectic percentage, and grain density were less accurate. The metamodels were very fast (less than 1 s); therefore, they can be used for optimization activities or be integrated into online prediction systems for the HPDC industry. The case study corresponds to several parts of aluminum cast alloys, used in the automotive industry, manufactured by high-pressure die casting in a multicavity mold.

Increasing the service life of die casting dies is an important goal of the foundry industry. Approaches are either material- or process-related. Despite new material concepts, hot work steels such as H11 are still predominantly used in the uncoated condition for die casting dies. In order to withstand the stresses that occur, this steel is used exclusively in the quenched and tempered condition. Required properties such as high high-temperature strength and high hardness combined with high toughness are, in principle, contradictory and can only be adjusted consistently over the entire die by furnace-based heat treatment. However, the results of various investigations have shown that improvements in the thermal shock resistance and wear resistance of hot work tool steels can be achieved by thermally influencing the microstructure near the surface. Based on these studies and related findings, an approach to surface heat treatment using the electron beam was developed. Due to the particle character of the radiation and the associated possibility of high-frequency beam deflection, the electron beam offers significantly greater flexibility in energy input into the workpiece surface compared with lasers or induction. The overall technological concept envisages replacing furnace-based heat treatment in the production of casting dies by localized and demand-oriented boundary layer heat treatment with the electron beam. The experiments include, on the one hand, the experimental determination of a suitable temperature–time interval with a focus on short-term austenitization. On the other hand, a simulation-based approach of boundary layer heat treatment with validation of a suitable heat source is investigated. Regarding short-term austenitization, the corresponding temperature and time range could be narrowed down more precisely. Some of these parameter combinations seem to be very suitable for practical use. The test specimens show a hard surface layer with a depth of at least up to 6 mm and a very tough buffer layer. Numerical simulation is used to estimate the resulting metallurgical microstructure and the achievable hardness as a function of the temperature–time interval. In addition, the results provided show the possibility of determining and optimizing the material properties by means of a simulation-based approach within the framework of a purely digital process planning and subsequently transferring them into a process planning. In the technical implementation, a temperature control was first established by means of a two-color pyrometer. In the further course of research, the pyrometer will be supplemented by an internally installed infrared camera, which will allow the reproducible setting of specified temperature profiles even for complex, large-area contours in the future.

For realizing complicated shapes of the inner cavity of zinc alloy castings by pressure die casting, the problem of poor leachability has to be solved and the high-strength requirement of the water-soluble salt core should be met. High-melting potassium chloride salt and low-melting potassium nitrate salt were used as the core materials. High-strength binary composite water-soluble salt core (WSSC) was formed by the process of melting and gravity pouring. The performance characteristics of the potassium chloride core, potassium nitrate core, and binary composite WSSC (20% KCl-80% KNO3) were investigated. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies were performed to examine the micro-morphology and phase composition of WSSC. The results indicate the following:the binary composite WSSC has excellent comprehensive performance, its bending strength can exceed 21.2 MPa, the 24 h hydroscopicity rate is 0.568%, the water-soluble rate can exceed 208.63 kg·min-1·m-3 in water at 80℃ and its surface has no cracks and folds unlike the pure salt core. Crack growth in the binary composite salt core occurs by deflection, which is the main reason for the improvement in bending strength.

It is necessary in factories to assess the severity of the surface defects of castings, as a slight surface defect will be taken as qualified when it brings no bad effect or it can be removed by the subsequent processing. In practical production, professional technicians visually inspect the surface defect severity according to their individual experience. Therefore, it is difficult for them to maintain the same standard and accuracy in the subjective, tedious and labor-intensive work. Recently, image processing techniques based on optical images have been applied to achieve better accuracy and high efficiency. Unfortunately, optical images cannot directly quantify surface depth, which works as a crucial factor in the practical assessment of surface defect severity. The surface roughness evaluation algorithm, which takes into account of both area and depth information of the assessed surface, was applied to directly characterize surface defect severity based on surface asperity rather than optical image. The results using standard casting pieces show that surface defect severity has no apparent dependence on surface roughness. However, the subsequent results show that the root-mean-squared-deviation (RMSD) of surface gradient of flow line defects positively correlates with the increase of defect severity. The other types of defect do not present such tendency. Thus, practical workpieces with flow line defects on the surface were used to verify the universality of this tendency. The results show that surface roughness of an unqualified workpiece is larger than that of a qualified workpiece after surface slope adjustment, but presents no obvious coincidence before the adjustment. In contrast, the RMSD of an unqualified workpiece, no matter before or after the adjustment, is larger than that of a qualified one.

For the die casting conditions of aluminium bronzes assumed based on the literature data, a thick-walled bush was cast, made of complex aluminium bronze (Cu-Al-Fe-Ni-Cr). After the cast was removed from the mould, cracks were observed inside it. In order to identify the stage in the technological production process at which, potentially, the formation of stresses damaging the continuity of the microstructure created in the cast was possible (hot cracking and/or cold cracking), a computer simulation was performed. The article presents the results of the computer simulation of the process of casting the material into the gravity die as well as solidifying and cooling of the cast in the shape of a thick-walled bush. The simulation was performed with the use of the MAGMA5 program and by application of the CuAl10Ni5,5Fe4,5 alloy from the MAGMA5 program database. The results were compared with the location of the defects identified in the actual cast. As a result of the simulation of the die-casting process of this bush, potential regions were identified where significant principal stresses accumulate, which can cause local hot and cold cracking. Until now, no research has been made of die-cast aluminium bronzes with a Cr addition. Correlating the results of the computer simulation validated by the analysis of the actual cast made it possible to clearly determine the critical regions in the cast exposed to cracking and point to the causes of its occurrence. Proposals of changes in the bush die casting process were elaborated, in order to avoid hot tearing and cold cracking. The article discusses the results of preliminary tests being a prologue to the optimization of the die-casting process parameters of complex aluminium bronze thick-walled bushs.

Recent research in the process of aluminum alloy die castings production, which is nowadays deeply implemented into the rapidly growing automobile, shipping and aircraft industries, is aimed at increasing the useful qualitative properties of the die casting in order to obtain its high mechanical properties at acceptable economic cost. Problem of technological factors of high pressure die casting has been a subject of worldwide research (EU, US, Japan, etc.). The final performance properties of die castings are subjected to a large number of technological factors. The main technological factors of high pressure die casting are as follows: plunger pressing speed, specific (increase) pressure, mold temperature as well as alloy temperature. The contribution discusses the impact of the plunger pressing speed and specific (increase) pressure on the mechanical properties of the casting aluminum alloy.

Aluminum–silicon alloys are commonly used in die-cast and additively manufactured (AM) light-weight components due to their good processability and high strength-to-weight ratio. As both processing routes lead to the formation of defects such as gas and shrinkage porosity, a defect-sensitive design of components is necessary for safe application. This study deals with the fatigue and crack propagation behavior of die-cast alloy AlSi7Mg0.3 and additively manufactured alloy AlSi12 and its relation to process-induced defects. The different porosities result in significant changes in the fatigue stress-lifetime (S–N) curves. Therefore, the local stress intensity factors of crack-initiating defects were determined in the high and very high cycle fatigue regime according to the fracture mechanics approach of Murakami. Through correlation with fatigue lifetime, the relationship of stress intensity factor (SIF) and fatigue lifetime (N) could be described by one power law (SIF–N curve) for all porosities. The relationship between fatigue limit and defect size was further investigated by Kitagawa–Takahashi (KT) diagrams. By using El Haddad’s intrinsic crack length, reliable differentiation between fracture and run out of the cast and AM aluminum alloys could be realized. SIF–N curves and KT diagrams enable a reliable fatigue design of cast and AM aluminum alloys for a finite and infinite lifetime.

The influence of Sm (Samarium) content on microstructure and mechanical properties of recycled die-cast YL112 aluminum alloys was investigated. The results show that many small Sm-rich particles form in the recycled die-cast YL112 alloys with Sm addition. At the same time, the secondary dendrite arm spacing in the YL112 alloys modified with Sm is smaller than that of the unmodified alloy. The eutectic Si of recycled die-cast YL112-xSm alloys transforms from coarse acicular morphology to fine fibres. Mechanical properties of the investigated recycled die-cast YL112 aluminum alloys are enhanced with Sm addition, and a maximal ultimate tensile strength value (276 MPa) and elongation (3.76%) are achieved at a Sm content of 0.6wt.%. Due to the modification of eutectic Si by Sm, numerous tearing ridges and tiny dimples on the fractures of tensile samples are observed.

The work is a continuation of research on the use of water mist cooling in order to increase efficiency of die-casting aluminum alloys using multipoint water mist cooling system. The paper presents results of investigation on crystallization process and microstructure of synthetic hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled a with water mist stream. The study was conducted for unmodified AlSi20 alloy and a modified one with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using a dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream and solution heat treatment allows in wide range for the formation of the microstructure of hypereutectic silumins. It leads to the growth of microstructure refinement and spheroidizing of phases in the casting.

The paper presents the results of research on the study of the possibility of accumulation of the lubricating layer coating on the surface of the separation process of foundry equipment with high pressure die casting aluminum alloys.

This article deals with reliability evaluation of the production process for die casting. Reliability of the production process was assessed on the basis of productivity and deformity. With suitably chosen production technology the increasing of labour productivity can be achieved alongside the required quality of aluminum

This paper provides an overview of alloy and process developments in aluminum and magnesium castings for lightweight automotive applications. Wear-resistant aluminum alloys, creep-resistant and high strength/ductility magnesium alloys have been developed for automotive applications. On the process front, vacuum-assisted die casting and high vacuum die casting technologies have been developed for high-integrity body and chassis applications. Thin-wall and hollow casting components are being produced by low-pressure die casting processes for structural applications. Overcasting technology is gaining traction and has enabled mixed material designs for automotive sub-systems such as engine cradles and instrument panel beams. Simulation tools developed to predict the interfacial interactions of the dissimilar components and the structural integrity of the overcast systems are being validated in the casting trials.

Die-casting dies are exposed to high thermal and mechanical loads. Thermal fatigue cracking of dies due to thermal cycling may importantly shorten the life-time of the die. Cracks degrade the surface quality of dies and consequently the surface of castings. In this study, thermal fatigue cracking of dies was analyzed during the process of die casting aluminium alloys. During the process cracks were observed and measured and their location and size were determined. Thermal and mechanical loads cause high local stresses and consequently surface cracks. First cracks occur as early as after 2000 cycles and propagate progressively with cycles.

Die casting process uses high productive level machines. Machine capacity utilization is a key goal in achieving minimum time consumption. Changeover procedure during die casting process is recognized as possible area for reducing time consumption. The SMED method has been improved by additional procedures simultaneously applying the 5S method. Their contribution is evident in recognition of internal and external activities, particularly while transferring internal activities into external ones in as many numbers as possible, by minimizing at the same moment the internal ones. The validity of the method and procedures are verified by an example application of die casting foundry for casting automobile parts. Significant time savings have been achieved with minimum investment.

The present paper addresses problems in laser welding of die-cast tools used for aluminum pressure die-castings and plastic moulds. To extend life cycle of tools various surface improvements are used. These surface improvements significantly reduce weldability of the material. This paper presents development of defects in repair welding of duplex-treated tool steel. The procedure is aimed at reduction of defects by the newly developed repair laser welding techniques. Effects of different repair welding process parameters and techniques are considered. A microstructural analysis is conducted to detect defect formation and reveal the best laser welding method for duplex-treated tools.

High-speed injection die casting is an effi cient manufacturing technology for upgrading aluminum die-cast products. However, defi ciencies (such as die damage in early period) due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die emperature analysis, fl ow analysis and thermal stress analysis). The potential countermeasures to solve the above problems were also proposed.

A semi-solid metal processing technique has been invented and is being developed for aluminium casting applications in Thailand. The technique uses fine gas bubbles to create convection necessary for modifying grain structure. Semi-solid metal processing of three aluminium alloys, A356, Al-4.4%Cu, and ADC12, was investigated. Results show that the novel technique successfully modified A356 and Al-4.4%Cu to become semi-solid slurry with solid fractions up to about 50%. Current developments show a feasibility of applying this technique with gravity casting and the capability to prepare semisolid slurry up to 2 kg of aluminium alloys for industrial production.

The temperature change of the die surface in practical aluminum alloy die casting process was analyzed,and a 2D model was formulated on the basis of a deep concave round cavity without sliding core to analyze the stress distributions along the die surface in detail. Equipment was designed to test the thermal state of the die steel in different thermal loading conditions. The results of stress analysis showed that, the value of thermal stress (maximum 1.5 GPa) caused in the die filling and die spraying stages was larger than the mechanical stress (maximum 85 MPa) caused in the die locking stage. The results of the thermal check experiment showed that there were three stages of die dissolving, and that the stress distribution shown by the samples' cracking routine was close to the die surface stress analysis.

The quality of aluminium alloy in the production process on the chemical composition basis was evaluated. The quality of casting alloy depends on the chemical composition of melt and on the technological process of production process. The basic elements such as Si, Cu, Fe, Mg and Al in melting were evaluated. The obtained data were compared with the guide data referred to in the standard for aluminium alloy.

After many years of development, die casting technology of metallic materials has been matured. In this paper,the lower-support and its injecting system were created with commercial software. And then the simulation software FLOW3D was applied to study the flow behavior of the melt during injection filling process. Both temperature field and defect distribution were simulated. Based on these results, the better injecting system with two additional overflows wasadopted.

This paper deals with a study of the failure mode of thin PVD coatings in alternated contact with molten aluminum alloy. CrN and ZrN monolayer coatings deposited through cathodic arc evaporation were used. The coatings morphology was assessed by SEM and their mechanical properties evaluated by nanohardness test performed at room temperature. An experimental test rig which cyclically immerses coated steel samples in molten Al-alloy and in a cooling bath was applied. The thermal gradient from the coating to the steel core was exalted by internal cooling channels placed in the internal cavity of samples. Periodical SEM inspections were performed to assess the damaging levels introduced by the test and to study the related decrease of substrate protection capability. Descriptions and interpretations of the damages evolutions were derived. The main conclusions achieved are that both coatings suffered by the formation of corrosion pits, which were due to a corrosion attack of the steel substrate localized at coating defects sites. In particular, at pores locations the corrosion was fast, whereas at droplets sites it required a certain incubation time. Once corrosion pits were formed they exhibited an initial tendency to expand laterally, but they did rapidly stabilize in terms of lateral dimensions. Later on two different failure modes acted in ZrN and in CrN. Extended delamination due to a marked mismatch of mechanical properties between the coating and the steel substrate developed in ZrN. On the contrary, thermal cracking due to lower hardness levels developed in CrN, but with limited delamination. Accordingly the steel substrate protection capability was evaluated to be higher in CrN than in ZrN. Keywords: PVD