Extrusion casting manufacture method of piston with reinforced pseudo-alloy circular groove

Abstract

The invention relates to an extrusion casting manufacture method of a piston with a reinforced pseudo-alloy circular groove. The extrusion casting manufacture method is characterized by including the preparation process steps: firstly, preparing aluminum alloy for the piston; secondly, preparing pseudo-alloy components; thirdly, manufacturing a pseudo-alloy preformed part, uniformly mixing pseudo-alloy powder particles, and pressing and sintering the mixed particles via a die so that a pseudo-alloy insert ring preformed part is formed; fourthly, melting, namely, placing the prepared aluminum alloy for the piston into a melting furnace for melting, and refining, deteriorating, homogenizing and refining alloy liquid after melting; fifthly, preheating the pseudo-alloy preformed part; seventhly, performing extrusion casting; eighthly, performing aging heat treatment for a piston blank and performing air cooling after the piston blank taps off; and ninthly, machining and performing surface treatment for the piston blank so that an aluminum piston finished product is obtained. Compared with the prior art, the extrusion casting manufacture method has the advantages that the piston with the reinforced circular groove is good in wear resistance, compact in material internal texture and remarkably improved in mechanical performance, and the method is high in process efficiency and low in manufacture cost.

Description

technical field [0001] The invention relates to a piston casting method, in particular to a method for manufacturing a pseudo-alloy reinforced ring groove piston used in the field of high-strength diesel engines with severe engine working conditions. Background technique [0002] At present, ZL108 and ZL109 cast aluminum alloys are generally used in automobile engine pistons in my country. The mechanical properties of the materials are tensile strength (Rm) 220MPa-240MPa, elongation (A) 0.5%-1.0%, and high-temperature (300℃) tensile strength 60MPa ~80MPa. High-strength diesel engines are developing towards high power and high load, and aluminum pistons are important reciprocating components of internal combustion engines, and their performance directly affects the performance and reliability of high-strength diesel engines. The aluminum piston usually has a cooling oil chamber in the thick part to cool the piston, and the first ring groove of the piston is equipped with a hi...

AI Technical Summary

Problems solved by technology

Using conventional metal gravity casting and sand casting aluminum pistons, it is easy to produce casting defects such as pores, shrinkage porosity, cracks, and slag inclusions, the microstructure density is poor, and the mechanical properties cannot meet the requirements of use. Not only that, conventional casting methods, production efficiency low, labor intensive

[0003] Existing pistons for diesel engines at home and abroad are usually reinforced with high-nickel cast iron inserts in the first ring groove, and the thick and large parts are usually equipped with cooling oil chambers to cool the pistons. The gravity casting process is used to shape the pistons. Defects such as low bonding strength between the cast iron insert ring and the aluminum matrix lead to short service life and poor reliability of the piston

[0004] During the research process of the "Eleventh Five-Year Plan" high-strength diesel engine piston, I found that: the aluminum alloy piston with the first ring groove cast high-nickel cast iron ring prepared by the gravity casting process has high nickel content in the hydraulic cycle fatigue simulation assessment test. The phenomenon that the cast iron insert is disengaged

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