Gasoline engine piston material and preparation method thereof

Abstract

The invention relates to a gasoline engine piston material and a preparation method thereof. The synthetic material comprises the following chemical constituents: Si, Fe, Cu, Mn, Mg, Ni, Zn, Ti, Pb and Al. The preparation method comprises the following steps: firstly, feeding an aluminum ingot into a smelting furnace, so as to heat and melt the aluminum ingot, feeding and stirring low-temperature a dregs remover, so as to adsorb impurities, continuously feeding other chemical constituents, heating until all the chemical constituents are completely molten, secondly, feeding a phosphate compound modifier to perform refining modification treatment, thirdly, feeding a high-temperature dregs remover, stirring the liquid level, then degassing and leaving to stand, fourthly, casting through a metal mold, and fifthly, performing T6 heat treatment on qualified piston blanks. According to the method, the constituents of aluminum alloy pistons is improved in terms of formula, the high-temperature strength, heat stability and strength of the aluminum alloy pistons are improved, meanwhile, the preparation method is improved, the mechanical property of the aluminum alloy pistons is improved, so that the aluminum alloy pistons can meet the requirements for recast supercharged direct injection pistons in the gasoline engine, and the production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of metal alloys and their preparation, in particular to a gasoline engine piston material and a preparation method thereof. Background technique [0002] The piston is called the heart of the engine. It is one of the most important parts in the engine. Its function is to withstand the gas pressure and transmit it to the connecting rod through the piston pin to drive the crankshaft to rotate. When the engine is working, the piston is directly in contact with the high-temperature gas with an instantaneous temperature of 2200°C, and its top temperature is above 300°C, and it is also subjected to a large gas pressure. Generally, the gasoline engine reaches 5-7Mpa, and the supercharged direct-injection gasoline engine is as high as 8~ 10 Mpa, the diesel engine is as high as 15-22MPa, or even higher, so the piston structure and materials used should meet the following requirements: ①High thermal strength; ②Good th...

AI Technical Summary

Problems solved by technology

With the improvement of engine power and emission standards, the ability of these materials to withstand high temperature loads is less and less able to meet the requirements

[0003] Chinese patent CN103060625A discloses a high-copper and high-nickel liquid die forging aluminum alloy piston material, in which Cu: 3.5-4.5%, Si: 13.5-14.5%, Mg: 0.05-0.25%, Fe: 0.4-1.05%, Ni: 1.5% -2.5%,Ti: 0.05-0.15%,Mn: 0.1-0.35%,Cr: 0.01-0.15%,Zn: 0.05-1%,Sn: 0.01-0.1%,Pb: 0.01-0.2%,Bi: 0.01- 0.08%, it is used in the snowplow engine, although its performance can be made thin and can meet the requirements of high strength, but due to the liquid die forging process, the piston structure is required to be simple, and the inner cavity of the piston must not have limited demoulding Structure, the inner mold of the mold corresponding to the inner cavity of the piston can only be made with a whole inner core straight off, otherwise it cannot be demoulded for production, the wall of the pin hole seat should be thin, because if the pin hole seat is too thick, the pin hole seat will form a hot node, It is easy to produce casting defects, and the obtained piston has poor high temperature resistance strength and contains small pores

Chinese patent CN103374674A discloses a high-strength aluminum alloy piston for diesel engines. Although its high-temperature performance has been improved and its wear resistance is good, it is only used in diesel engines, and its performance cannot meet the thin-walled high-strength performance of gasoline engine supercharged direct injection pistons. Requirements, because the piston wall of the diesel engine is thick, the speed is low, and the wear resistance is more pursued, and the Ni content is high, and the domestic source of nickel is lacking, which increases the manufacturing cost of the piston