Silumin piston contour forging technique and mold

Abstract

The invention discloses a die-forging process for high-silicon aluminum alloy pistons and forging die. The process can directly mold a high-silicon aluminum alloy extrusion bar blank in one step into a piston forging piece heated up to 400-470 DEG C which has a transversal flash edge of a thickness no more than 1.2 mm along the die parting surface, and the piston forging is obtained after cutting the flash edge. The forging die comprises an upper die and a lower die. The die cavity of the lower die is provided circumferentially with a flash edge groove that consists of a bridge portion and a storage portion. The width/thickness ratio of the bridge portion close to the die cavity is 8-10. The upper and the lower dies are guided and positioned based on the engagement of two pilot pins and the corresponding pilot holes. The forging die is mounted to work on a high-speed hydraulic press (4000KN). The inventive process has the advantages of good stability, simple die structure and easy operation.

Description

technical field [0001] The invention provides a high-silicon aluminum alloy piston die forging process and mold, which can be directly used in the die forging production of column pistons, key parts in automobiles, airplanes and household air-conditioning compressors, and belong to the plastic forming technology of metal materials field. Background technique [0002] The traditional method of producing high-silicon aluminum alloy pistons is to use the die-casting process. The process is to pour molten liquid aluminum alloy into the pressure chamber of the die-casting machine, so that the liquid metal fills the cavity of the die-casting mold under pressure and high speed. And it is formed and crystallized under pressure to obtain castings. This die-casting process is used to produce high-silicon aluminum alloy pistons with high strength, high corrosion resistance, and high air-tightness requirements. The main problem is that there are pores and inclusions in the die-casting ...

AI Technical Summary

Problems solved by technology

[0003] At present, another more advanced process for producing high-silicon aluminum alloy pistons is to use the method of secondary or tertiary plastic forming. The process is: extruded bar → blanking → heating → billet making → heating → molding plastic forming → Edge trimming→subsequent processing, but this process is easy to cause wrinkles and surface cracks on the surface of the high-silicon aluminum alloy piston, and the die-casting parts have defects such as poor internal structure and low strength

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