• 한국주조공학회지
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• 제20권1호
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• pp.3-12
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• 2000

The lead content of drinking water has been restricted to less than 15 ppb by Environmental Protection Agency (EPA) in USA. This has led to extensive research and development work at the Materials Technology Laboratory (MTL) of CANMET, a Canadian Government research laboratory, on the development of low-lead and lead-free copper alloys for plumbing applications. Attentionhas also been focused on the environmentally friendly and energy efficient permanent mold casting process to minimize the disposal of foundry sand contaminated by lead due to the use of leaded alloys in the non-ferrous foundries. A new series of alloys called SeBiLOY contaning Bi and Se been introduced to replace lead in the leaded alloys. This paper addresses some important casting characteristics such as fluidity, hot tear resistance, mechanical properties and microstructure of lead-free alloys such as SeBiLOY III and low-lead alloys such as silicon brass, silicon bronze and yellow brass in gravity permanent mold casting.

• 한국주조공학회지
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• 제5권2호
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• pp.85-96
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• 1985

In order to investigate the effect of particle size and distribution of silica sand on the characteristics of investment, W/P ratio, setting time, temperature change during setting, setting expansion, thermal expansion and compressive strength of the investments were measured. In this experiment, magnesia clinker and mono ammonium phosphate were used as binder, and particle size and distribution of silica sand were classified for convinence into 10 categories. The main results obtained from this investigation were summerized as follows. 1. W/P ratio decreased with increase of particle size and evenness in distribution of sand grain. 2. Setting time decreased with increase of evenness in distribution of sand grain, and temperature during setting increased with evenness in distribution of sand grain. 3. Setting expansion decreased with increase of particle size, while it increased with evenness in distribution of sand grain. 4. Thermal expansion decreased with increase of particle size. 5. Compressive strength increased with increase of particle size and evenness in distribution of sand grain. From above results, G.F.N. 250 sand which contains 30% of 50-100 mesh could be recommended for investment casting.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.225-226
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• 2007

• 산업경영시스템학회지
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• 제4권5호
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• pp.1-10
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• 1981

The purpose of this study is to cut down cost of production and improve the productivity of industry through quality improvement of castings and reduction of defectives by applying the experimental design to the foundry sand mixing operation done at molding department in the foundry. Among the related foundry sand mixing factors which have an effect on casting the experiment of which factors have a dominant effect on quality improvement was performed between two different levels by means of "$2^n$ type orthogonal array." The results cail be summarized as follows ; (1) The optimum conditions per each foundry sand mixing between two different levels proved to be such as $A_2$(used sand) : 24 unit (172.8kg), $B_2$(unused sand ) : 2 unit (15.0kg), $C_2$(binder) : 2.5 unit (4.4kg). $D_2$(addition agent) : 1 unit(1.4kg) and $F_1$(moisture) : 7.4%(14.6kg). (2) As a result of the application of experimental design, the fraction defective during the foundry sand mixing operation turned out to be reduced front 6.6% to 2.04%. (3) For the purpose of cost-down, It was found that the optimum level decision of foundry sand mixing for various castings is required to be made by means of experimental design.al design.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.71-75
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• 2006

Problem of the environmental pollution and pollution by vast quantity occurrence of industrial waste by progress of industry is risen recently. Is real condition that waste foundry sand to be industrial waste that happen in casting industry of them has much the occurrence amount and the processing method is depending on most simplicity reclamation and so on. Therefore, by using waste foundry sand in the world by fine aggregate for mortar in recycling side of industrial waste necessity of development for new principal parts aggregate is risen along with rise of aggregate price by exhaustion phenomenon of natrual resources, wish to analyze physical and mechanical properties special quality and foretell practical use possibility availability.

• Design & Manufacturing
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• 제15권2호
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• pp.30-35
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• 2021

The casting method uses a mold to solidify a liquid metal to make a solid metal. Since it uses a liquid metal with the least deformation resistance, it has the characteristic that it can easily manufacture even a complex shape. However, the process of solidifying a liquid metal into a solid metal inevitably involves a volume change and contains internal defects such as shrinkage holes. Therefore, in the design of the casting plan, an excess volume called a pressurization compensates for the volume shrinkage. in the product, and it induces the shrinkage hole defects to occur in parts other than the product1). In this study, casting analysis was performed using casting analysis software (anycasting) in order to optimize the design of the tilting gravity casting method for automobile brackets. In particular, the filling and solidification analysis according to the shape and volume of the pressurized metal was conducted, and applied to the actual product to study the effect of the pressurized metal on the shrinkage defect. Through this study, it is possible to understand the effect of the pressure metal on shrinkage defects in the actual product and propose a design of the pressure metal that improves reliability and productivity.

• 한국주조공학회지
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• 제13권5호
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• pp.450-461
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• 1993

AC4C alloy casts in the metallic mold, zircon sand mold, silica sand mold and shell mold with the pouring temperatures of 680, 710 and $740^{\circ}C$ have been investigated. The tensile strength, elongation and hardness of AC4C alloy castings have been influenced by the kind of molds used. The mechanical properties in zircon sand mold castings were greater than those in other sand mold castings, but were inferior to the properties in metallic mold castings. Eutectic Si particle size and DAS were increased in the order of metallic mold, ziron sand mold, silica sand mold and shell mold. Also, they were increased with the increase of pouring temperatures. DAS, eutectic Si particle size and grain size decreased with the increase of mechanical properties as the cooling rate increased. The eutectic Si particle size and DAS of AC4C alloy castings after T6 treatment were decreased in as-cast. The variation of eutectic Si particle size has been effected on the tensile strength, elongation and fractured surface.

• 한국주조공학회지
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• 제20권5호
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• pp.336-343
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• 2000

The effects of casting variables and alloying elements on the fluidity of thin wall cast stainless steels were investigated. Melts were poured into the sand molds to produce thin wall test castings. The length of it was 245 mm and the thickness varied at the interval of 0.5 in the range of 1.6 to 2.6 mm. For the same casting condition, the fluidities of austenitic stainless steel, ferritic, precipitation hardenable and martensite ones were better in the order. The higher the pouring temperature, the shorter the pouring rate and the better the fluidity were. The fluidity was increased with the addition of Cr and decreased with W and Nb.

• 한국환경보건학회지
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• 제18권1호
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• pp.1-5
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• 1992

A study was performed to measure the heavy metal concentrations of suspended particles in iron castings during February, 1990. The heavy metal concentrations were analyzed using patricles atomic absorption spectrophotometer. The results were as fellows 1. The concentrations of suspended paticles by casting process were at furnace 4.19mg/m$^{3}$ at pouring 2.93mg/m$^{3}$ at nonferrous furnace 3.90mg/m$^{3}$, at molding 1.17mg/m$^{3}$, jung ja 2.23mg/m$^{3}$, desanding 5.42mg/m$^{3}$, sand treatment 4.82mg/m$^{3}$, finishing 1,20mg/m$^{3}$. 2. Among the total of 8 iron casting workplaces, the concentrations Fe of furnace was 0.36mg/m$^{3}$, Cu of nonferrous furnace 0.02mg/m$^{3}$, Pb of pouring 0.02mg/m$^{3}$, Cr of desanding 0.01mg/m$^{3}$ and Mn of furnace 0.03mg/m$^{3}$.

• 한국주조공학회지
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• 제3권1호
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• pp.13-21
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• 1983

In order to determine the feeding distance of aluminiun alloys (Alsi7Mg and AlCu4Ti) bar castings in the sand mold, the distance of the sound castings has been observed by radiograph for various risers, melt treatment, and casting design. Variation of porosity and hardness with the distance from the riser were also measured in order to determine the casting soundness. The results obained were as follows; 1) The modulus of riser should be 1.4 times of the casting`s 2) The maximum distance which can be made sound is greatly dependent on chemical composition and ingate location, and follows the rules given by the formula; a) When the melt flows into the casting first, and the riser afterward, D = 37.7 ${\sqrt{T}}$ for AlSi7Mg D = 31.2 ${\sqrt{T}}$ for pure aluminium D ${\ge}$ 54.8 ${\sqrt{T}}$ for AlCu4Ti Where T = casting thickness in mm Of this maximum distance, $aa{\sqrt{T}}$ for AlSi7Mg and 7.5 ${\sqrt{T}}$ for pure aluminium is made sound by the chilling effect of the casting edge. b) When the melt flows into the casting passing through the riser, $30{\times}30{\times}600mm$ bars can be made sound in all cases 3) Percentage of porosity is higer in AlCu4Ti than AlSi7Mg. And it is increased gradually by moving closer to the riser in case of $30{\times}30{\times}600mm$ bars, but for the $30{\times}30{\times}600mm$ bars it is increased gradually by moving closer to the center of bars. 4) Hardness variation is similar to the tendency of porosity. And it decreased gradually with approaching to the center in case of $30{\times}30{\times}600mm$ bars.