• 한국기계가공학회지
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• 제7권1호
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• pp.9-16
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• 2008

It is important not only to reduce the casting defects of piston but also to improvement in the mechanical properties(hardness) of piston for the air compressor. The blow hole is typical casting defects in the conventional cast of aluminium alloy(AC8A-T6) piston. Because of the heat treatment method, mechanical properties of the aluminium alloy for piston was decided on the heat treatment method and cycle. Therefore, we tested on the development of mechanical properties and on the casting defects of piston for the air compressor in accordance with the heat treatment and casting condition. After the heat treatment and casting was carried out as several times, and was compared with the imported piston. As a result of several investigations; microstructure, hardness and casting defects of piston was changed under the influence of the heat treatment and casting method. When the cooling rate was controlled and the uni-cast method used, it bas the same mechanical properties and microstructure.

• 한국정밀공학회지
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• 제17권8호
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• pp.87-93
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• 2000

Powder Forging technology is being developed rapidly because of its economic merits and the possibility of lightening parts by replacing steel parts with aluminum ones especially in automotive parts manufacturing. Recently Powder Forging process is widely used for manufacturing primary mechanical parts as a combined technology of P/M and precision hot forging. This paper describes the process conditions for the powder forging of Aluminium alloy piston. For example powder alloy design preform design by FEM simulation cold of compaction of specimens and preform sintering of preform powder forging process. The characteristics of sintered compaction of specimens and preform sintering of preform powder forging process. The characteristics of sintered products and final forged piston ones are investigated with tensile strength hardness ductility and so on. Eventually its results prove the improve mechanical properties of the piston produced by powder forging.

• International Journal of Precision Engineering and Manufacturing
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• 제2권4호
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• pp.69-74
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• 2001

Powder forging technology has been introduced to manufacture the parts for vehicles. This paper describes the process conditions for the powder forging of aluminium also piston for vehicles including the determination of composition of aluminum alloy by experiment, preform design by FEM simulation, coed compaction of aluminum alloy powder, sintering of preform, and the experiment of powder forging. The mechanical properties such as hardness, tensile strength, and elongation of the farmed piston were invested and compared with casted piston and forged piston. The tensile strength and hardness of the piston formed by powder forging technology were much more excellent than other pistons.

• 한국정밀공학회지
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• 제17권11호
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• pp.63-68
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• 2000

The purpose of this paper is to compare the forging effects according th the shape of preforms of cup shaped powder forging product, and extend the application of powder forging technology to more complicated cup-shaped products like pistons. In order to this, preforms are provided by compacting, sintering, and machining in various shapes, then forged to final shape of products. The workability for sintered aluminium powder material is examined. Density and strain loci of forged products are compared, and the most effective shape of preform is proposed. The preform for a piston of 50mm in diameter is provided and hot forged to final product.

• International Journal of Precision Engineering and Manufacturing
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• 제3권4호
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• pp.37-42
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• 2002

The purpose of this paper is comparing the forging effect according to the shape of preforms of cup shaped powder forging product, and extending the application of powder forging technology to more complicated cup-shaped products like pistons. In order to achieve this, preforms are provided by compacting, sintering, and machining to 5 different shapes, then forged to the final shape of products. The workability for sintered aluminium powder material was examined and confirmed its slope was 0.5 as known. Density and strain loci of forged products are also evaluated and compared. On the basis of the results, the most effective shape of preform was proposed. The preform for the piston which is 50mm in diameter was prepared and hot forged successfully to the final product.