Papers by Keyword: Die Casting

Abstract: The performance of three kinds of mold lubricants was evaluated by testing the flow length of Al-4.7%Mg alloy. The lubricants tested were a heat-insulating type with inorganic compounds (10~20%), a heat-insulating type with organic acid salts (~10%) and a water-soluble type with mineral oil (20~30%). The flow length of the alloy was longest when using the heat-insulating type with inorganic compounds, and shortest with the water-soluble type with mineral oil. Additionally, data variation was largest with the heat-insulating type with inorganic compounds, and smallest with the water-soluble type with mineral oil.

Abstract: Aluminum materials are used in a wide field for household appliances, aircraft, cars, ships, and construction. This research aims to obtain a new material based on aluminum magnesium silicon (AlMgSi) alloy as an alternative material to replace the steel base material in the shaft propeller product. In this paper, we will use the die-casting method to investigate corrosion resistance and the microstructure of the propeller shaft with AlMgSi aluminum alloy base material. The main base material used is 6063 aluminum alloy, with variations in the addition of Si (1, 2, 4 wt%). Alloy Al6063 is heated to a temperature of 720°C to reach a complete liquid state. Then the temperature is lowered to 645°C, then the Si element is inserted into the heating furnace and stirred. Then the temperature is lowered to 615°C, then the Mg element is added, then stirred thoroughly by a mechanical stirrer. The rotational speed of the stirrer is 70 rpm and the stirring time is 240 seconds. They were then heated to a pouring temperature of 680°C. The mold is heated to a temperature of 265°C. Then poured into the mold and pressed 7 MPa. The cast is cooled at room temperature. Then the casting products were heat treated with a solution treatment temperature of 485°C for 3600 seconds and quenched. After that, the casting products were treated with artificial aging. The results of this study show corrosion resistance increases along with the addition of variations of Silicon. The highest corrosion rate was obtained by adding Si as much as 4 wt% of 511.28 mm/y. With the addition of variations of Silicon 0 wt%, 1 wt% and 2 wt% showed the corrosion rate of 173.35 mm/y, 201.60 mm/y, 233.49 mm/y. The microstructure shows differences in grain structure. materials with variations of si 0 wt% and materials with variations of si 0 wt%, 1 wt%, 2 wt% and 4 wt% have different grain sizes. The intermediate phase (Mg₂Si) was mostly formed at Si 4% wt variation. So this study proves that adding silicon elements can increase grain sizes and refiner the propeller shaft.

Abstract: In this research, different types of Mg-Zn based intermetallics that appear in the Mg-Zn alloy system were synthesized by conventional casting route. Consequently, the structural, mechanical, electrical, and magnetic properties of these Mg-Zn intermetallics were thoroughly studied. Every casting underwent a trivial loss of Mg by oxidation which resulted in slightly higher weight percentages of Zn. X-ray Diffraction (XRD) analysis confirmed the coexistence of several intermetallics in each sample. The morphology of the samples was studied under Optical and Field Emission Scanning Electron Microscopes and the phases were identified by Energy Dispersive Spectroscopy (EDS). Differential Scanning Calorimetry (DSC) analysis further confirmed many of the available phases found. Mainly five intermetallics i.e., Mg₅₁Zn₂₀, MgZn, Mg₄Zn₇, MgZn₂ and Mg₂Zn₁₁ were observed in the structures. The cast sample which is rich in Mg₂Zn₁₁ showed the highest compressive strength (122.6 MPa) and electrical conductivity of 10.47 S/m. From Vibrating Sample Magnetometry (VSM) analysis it was found that three of the samples are soft ferromagnets whereas only the samples abundant in MgZn₂ content showed paramagnetic behavior with maximum magnetization of 0.66 emu/gm.

Abstract: This project aims to investigate and compare the tribological properties of copper-based alloys produced by the die-casting method. Tribological properties, such as wear resistance and frictional behavior, play a crucial role in determining the suitability of materials for various engineering applications. Copper has many useful properties, such as high thermal and electrical conductivity, corrosion resistance, and antibacterial properties. It is used in a variety of industries, including electrical and electronics, construction, transportation, and healthcare. The study involves conducting wear tests on various copper-based alloys using a linear reciprocating tribometer. These tests were performed under different loading conditions (5N, 10N, and 15N), varied time durations (5 min, 15 min, and 30 min), Wear rates and morphologies of the specimens were determined by SEM. The effect of composition, microstructure, and hardness on the wear behavior of copper-based alloys has been carried out. The correlation between hardness and wear resistance was analyzed. The findings of this study could provide valuable information for the selection and optimization of copper-based alloys for trigolocal applications. The copper alloys has been characterized by an optical microscope, scanning electron microscope, and Energy dispersive X-ray analysis was used to analyze the wear surfaces.

Abstract: In the actual semi-solid die-casting production, the existence of several uncertain factors can impose an effect on the final product quality, which poses a challenge to semi-solid production. However, data analysis such as machine learning (ML) can help producers eliminate this problem. In order to quickly identify defective castings, a new model of predicting quality by real-time injection pressure data will be generated in terms of ML in this research. Quality assessment will be based on non-filling defect, density and tensile properties. The result of cross-validation shows that the classifier can achieve a confidence level of 0.95 for the quality classification. In addition, this research will find key intervals by the importance given by the model and analyze the effects of process on filling pressure. According to the result of feature screening, the surface quality problems are related to speed-pressure conversion and feeding displacement of plunger, the flowing state of slurry in filling affects the formation of defects and tensile properties. This work will make semi-solid die casting more automatically and efficiently, and thus provides support for semi-solid sustainable development.

Abstract: This research studied the effect of tin (Sn) on the surface dullness of ENAC44300 aluminum alloy commercial grade for die casting applications.Tin impurities in the alloy composition led to surface dullness which degraded the quality of the alloy. This investigation found that bulk structure as well as microstructure were affected by the presence of high Sn content. Porosity increased in the amount and size and microstructural change was evident when the alloy containing high Sn (0.67%) was homoginized at 550°C.

Abstract: An aluminum alloy, Al–4.8%Mg–2%Si, was cast by die casting and thixocasting, and the properties of the cast specimens were investigated. When the poured molten metal temperature was lower than 640 °C during die casting, it was lower than the liquidus temperature, and the metal became a semisolid slurry in the sleeve of the die casting machine; this fulfills the conditions for rheocasting. A tension test was conducted to investigate the effects of semisolid casting on the mechanical properties of Al–4.8%Mg–2%Si. The ultimate tensile strength and elongation of the ingots cast by die casting and rheocasting were affected by the size of ingot. When the ingot had a circular base of 4.5 mm diameter, the ultimate tensile strength and elongation were excellent; however, when the cross section of the ingot was a square with a side length of 20 mm, the tensile strength and elongation were inferior. The thixocasting was conducted using square ingots with a side length of 20 mm, and the tensile strength and elongation were poor in this case as well. The results of this study demonstrate that semisolid casting cannot improve the mechanical properties of Al–4.8%Mg–2%Si ingots with a high thickness. Semisolid casting cannot produce fine-grained Mg₂Si, and the mechanical properties of the material could not be improved by this casting method.

Abstract: The article considers the requirements for protective coatings operating in the conditions of injection molding of non-ferrous metal alloys, among which the most important are the provision of crack resistance and wear resistance of the forming surface. It is revealed that single-layer coatings applied by the physical vapour deposition method, regardless of its composition, are not able to fully meet the formulated requirements. It is established that multilayer coatings provide increased performance of structural elements of molds in comparison with single-layer ones.

Abstract: It is known from theory that coatings on the forming surface increase the service life of injection molding molds. In practice, the most widespread method of nitriding, which has a number of undeniable advantages, while there are other promising coatings. Therefore, the article considered coatings applied by the physical vapour deposition method in comparison with nitriding. The comparison was carried out on the basis of pressure and temperature indicators on the walls of the forming surface of the working inserts of the molds.

Abstract: The effects Si and Mn addition on the fluidity length, mechanical properties, and casting cracks of a die-cast Al-4.5%Mg alloy were investigated. The Si content was 1, 2, or 3 mass% and the Mn content was 0.3, 0.6, or 0.9 mass%. Both Si and Mn did not affect fluidity. Si content of more than 1 mass% improved casting crack resistance. The effect of Mn on casting cracks was weaker than that of Si. When Si content was 2 mass%, both tensile stress and elongation were good. Mn did not affect the mechanical properties.