• 한국산업융합학회 논문집
• /
• 제17권3호
• /
• pp.122-135
• /
• 2014

This paper was studied on the horizontal continuous casting of Al-xSi(x=10~15%) aluminum alloy. The experiments of the horizontal continuous casting was carried out by the horizontal continuous casting machine for various casting conditions and investigated on fracture types and mechanisms. Surface defect types for the horizontal continuous casting is also investigated. And the study was carried out that the horizontal continuous casting conditions such as casting temperature, cooling rate, and drawing speed affect the hardness and primary silicon size of Al-xSi(x=10~15%) aluminum rod bar. Casting temperature within this experiment conditions don't affect on the hardness of rod bar but the higher casting temperature is the smaller primary silicon size. The higher cooling rate and drawing speed have the higher hardness and the smaller primary silicon size.

• 한국생산제조학회지
• /
• 제25권3호
• /
• pp.198-203
• /
• 2016

Computer-Aided Engineering (CAE) durability analysis and experiments of an aluminum alloy brake pedal were carried out for the car lighter by die casting method. In the CAE analysis, KS standards and criteria of the Volvo Car Corporation were applied, and in the experiment, KS standards were applied. The CAE analysis results show that aluminum alloy brake pedals are stronger than the conventional steel brakes pedals because the yield strength of the aluminum alloy increased by almost 97% over that of steel. Further, the structures of the cylinder and the frame were reinforced with increasing thickness of flame and were changed to suit the die-casting process. Through a durability test based on the KS standard, the strength of a prototype of the aluminum alloy brake pedal was confirmed to be sufficient.

• 대한금속재료학회지
• /
• 제56권11호
• /
• pp.805-812
• /
• 2018

High pressure die casting is one of the precision casting methods. It is highly productivity and suitable for manufacturing components with complex shapes and accurate dimensions. Recently, there has been increasing demand for efficient heat dissipation components, to control the heat generated by devices, which directly affects the efficiency and life of the product. Die cast aluminum alloys with high thermal conductivity are especially needed for this application. In this study, the influence of elements added to the die cast aluminum alloy on its thermal conductivity was evaluated. The results showed that Mn remarkably deteriorated the thermal conductivity of the aluminum alloy. When Cu content was increased, the tensile strength of cast aluminum alloy increased, showing 1 wt% of Cu ensured the minimum mechanical properties of the cast aluminum. As Si content increased, the flow length of the alloy proportionally increased. The flow length of aluminum alloy containing 2 wt% Si was about 85% of that of the ALDC12 alloy. A heat dissipation component was successfully fabricated using an optimized composition of Al-1 wt%Cu-0.6 wt%Fe-2 wt%Si die casting alloy without surface cracks, which were turned out as intergranular cracking originated from the solidification contraction of the alloy with Si composition lower than 2 wt%.

• 한국생산제조학회지
• /
• 제25권3호
• /
• pp.204-210
• /
• 2016

This study analyzed the amount of displacement of window wipers according to pressure by using finite element analysis (FEA) with KS standards for aluminum alloy window wipers manufactured by die-casting method. The product design was changed over four steps considering the die-casting process to achieve strength greater than that of the conventional steel window wiper. According to the FEA results, the strength of final aluminum alloy window wiper improved by 55% over that of a steel window wiper, and the weight of the former was less by approximately 45%. Therefore, there is the possibility of module downsizing for driving motor capacity. Further, the cost competitiveness improved, and the manufacturing process of aluminum alloy window wipers was simplified.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 춘계학술대회논문집
• /
• pp.102-106
• /
• 1999

One of the main causes of unwanted dimensional changes in precision metal mold casting parts is excessive and irregular residual stresses induced by temperature gradients and plastic deformation in the solidifying shell. Residual stresses can also cause stress cracking and lower the fatigue life and fracture strength of the casting parts,. In the present study aluminum alloy casting system with metal mold equipped with electrical heating elements and water cooling units was designed and the casting specimens were produced to quantify the effects of different cooling conditions on the development of residual stresses. the layer removal method was used to measure the biaxial residual stresses in casting specimens produced from the experiments. The experimental results agreed with Tien-Richmond's theoretical model for thermal stress development for the solidifying metal plate

• 한국주조공학회지
• /
• 제31권3호
• /
• pp.101-105
• /
• 2011

• International Journal of Precision Engineering and Manufacturing
• /
• 제6권3호
• /
• pp.56-59
• /
• 2005

Aluminum alloy casting is gaining increased acceptance in automotive and electronic industries and especially, squeeze casting is the most efficient method of mass manufacturing of such parts. In this study, the microstructures and mechanical properties of Al-7.0Si-0.4Mg(AC4C) alloy fabricated by squeeze casting process for development of fuel system parts (fuel rail) are investigated. The microstructure of squeeze cast specimen was composed of eutectic structure aluminum solid solution and $Mg_2Si$ precipitates. The tensile strength of as-solid solution treatment Al-7.0Si-0.4Mg alloy was 298.5MPa. It was found that Al-7.0Si-0.4Mg alloy had good corrosion resistance in electrochemical polarization test.

• Archives of Metallurgy and Materials
• /
• 제67권4호
• /
• pp.1543-1546
• /
• 2022

The aluminum composite with dispersed high entropy alloy were developed by stir casting involving the powder-in-tube method. First, Al_0.5CoCrCuFeNi high entropy alloy (HEA) powder was made by mechanical alloying, and the powder was extruded in a tube-type aluminum container to form HEA precursor. The extruded HEA precursor was then dispersed in the aluminum matrix via stir casting. As a result, Fe-Cr-Ni based high-entropy phases was uniformly formed in the aluminum matrix, revealing ~158, 166, 235% enhancement of tensile strength by incorporating 1, 3, and 5 wt% HEA particles, respectively.

• 대한기계학회논문집A
• /
• 제26권3호
• /
• pp.461-470
• /
• 2002

The present paper investigates the effect of hot isostatic pressing (HIPing) on mechanical properties, e.g., tensile strength, ductility and impact absorption energy of sand and die casted aluminum alloys. After HIPing at various temperatures and pressure conditions, uniaxial tensile test and Izod impact test of the samples were carried out. The experimental results showed improvements in uniaxial tensile strength, elongation and Izod impact toughness of sand casted aluminum alloy, while deterioration of a tensile strength fur die casted aluminum alloy. The effect of HIPing for microstructure of the cast aluminum alloy was also investigated.

• 한국주조공학회지
• /
• 제38권6호
• /
• pp.121-131
• /
• 2018

The effect of additives on the castability of the AC2BS aluminum alloy, which contains 35% recycled scrap, was investigated. For the wide utilization of the recycled scrap AC2BS aluminum alloy, the research results were compared to those with the AC2B virgin alloy, which is typical Al-Si-Cu alloy system. It was confirmed that the addition of Al-5%Ti-1%B increased the ${\alpha}$-Al nucleation temperature during solidification and decreased the grain size through cooling curve and microstructural observations of the recycled alloy. It was also found that an addition of Al-10%Sr decreased the eutectic Si growth temperature during the solidification process and modified the shape of the eutectic Si of the recycled alloy. The characteristics of fluidity, shrinkage and solidification crack strength were evaluated. For the AC2BS aluminum alloy containing 35% recycled scrap, both ${\alpha}$-Al grain refinement due to Ti-B and eutectic Si modifications due to Sr contributed to the improvement of the fluidity. The macro- shrinkage ratio increased with additions of both Al-10%Sr and Al-5%Ti-1%B and the micro-shrinkage ratio increased with the addition of Al-10%Sr but decreased with the addition of Al-5%Ti-1%B. The casting characteristics of TiB and Sr-treated AC2BS aluminum alloy containing 35% recycled scrap are similar to those of AC2B virgin alloy. The improvement of the solidification crack strength of the AC2BS aluminum alloy was possible by the reduction of the grain boundary the stress concentration through the enhancement by both ${\bullet}{\cdot}$-Al refinement and eutectic Si modification. More extensive use of the AC2BS aluminum alloy containing 35% recycled scrap can be expected in the future.