KR20110139534A - Heat-resistant aluminum alloy for powder-forged piston - Google Patents

Abstract

PURPOSE: A high heat resistant aluminum alloy for power forging piston is provided to improve high temperature fatique strength more than the existing alloy unit by 50%. CONSTITUTION: A high heat resistant aluminum alloy for power forging piston comprises aluminum, silicon, iron, copper, manganese, titanium and zirconium. Silicon is 20~25 weight%. Season is 4~6 weight%. Copper is 1~3 weight%. Manganese is 0.3~0.7 weight%. Atomization process is performed after titanium and zirconium alloy. The titanium and zirconium are made to be 10~100μm.

Description

Heat-resistant Aluminum alloy for powder-forged piston

The present invention relates to a high heat-resistant aluminum powder alloy that can be applied to forged pistons for ultra high-power engines of 130 bar or more. It is to help improve.

In general, developed countries and other countries around the world are making efforts to curb environmental pollution by strengthening various environmental regulations, and in order to cope with the ever-increasing environmental regulations, the automobile industry is continuously researching to improve fuel efficiency. Accordingly, the demand for higher power for automobile engines is getting stronger.

In addition, the A4032 continuous casting alloy, which has been applied to pistons as an alternative material recently, is expected to have a heat resistance limit of 130 bar, which is an ultra-high power engine (130 bar or more) for significant improvement in fuel efficiency. Piston development requires a new development of a new aluminum piston material with significantly improved physical properties.

The present invention has been studied in view of the above points, the excess of silicon (Si), iron (Fe), copper (Cu) in the aluminum so that the heat resistance characteristics can be further improved compared to the current A4032 continuous casting material ) Was added to form a new kind of intermetallic compound (AlSiFeCu-based).

At this time, when a general cooling rate is applied, the above intermetallic compound is formed on the microstructure in the form of a needle-shaped coarse shape, and thus the physical properties are rather deteriorated. Therefore, the micro-atomization process is applied to a few μm. The production of spherical intermetallic compounds of size was induced.

By applying T6 heat treatment to maximize the effect of strengthening the dispersion and precipitation of intermetallic compounds, the purpose is to provide a new high heat-resistant aluminum powder alloy that has improved the tensile strength and fatigue strength by more than 50% compared to the existing A4032 continuous castings. have.

The present invention is a high heat-resistant aluminum powder alloy for powder forged piston, for this purpose, the present invention is based on the aluminum (Al), the silicon (Si) 20 to 25% by weight, iron (Fe) 4 ~ 6% by weight, 1 to 3% by weight of copper (Cu), 0.3 to 0.7% by weight of manganese (Mn), and other alloying elements, such as Ti and Zr, are added and alloyed, followed by an atomization process. Achievement is made by making the micrometer size.

According to the high heat-resistant aluminum powder alloy for powder forged piston according to the present invention as described above, through the addition of excess Si and Fe, atomizing and sintering / T6 heat treatment process, the effect of increasing the high temperature fatigue strength of more than 50% compared to the existing alloy There is an advantage that can be widely used as a high-strength, high heat-resistant material that can be obtained, and can be applied to ultra-high power, high-combustion pistons to be developed in the future.

1 is a photograph of the development alloy powder and microstructure and A4032 continuous casting material microstructure.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The present invention contains the aluminum (Al) as a main component, 20 to 25% by weight of silicon (Si), 4 to 6% by weight of iron (Fe), 1-3% by weight of copper (Cu), manganese (Mn) 0.3 After alloying by adding ~ 0.7% by weight and other alloying elements, such as Ti, Zr, and the like to provide a high heat-resistant aluminum powder alloy made of 10 ~ 100㎛ size through an atomization process.

At this time, the added Si is added to produce fine primary Si particles and AlSiFeCu-based intermetallic compounds to increase the heat resistance at high temperature, the amount may be added from 20% by weight to 25% by weight. When added below 20% by weight, the amount of fine primary Si may be insufficient due to the quenching effect, and when added above 25% by weight, primary Si is coarsened and causes a decrease in physical properties. Iron (Fe) for forming the intermetallic compound may be added from 4% by weight to 6% by weight. At this time, when added below 4%, the intermetallic compound is not produced due to the quenching effect, and it cannot be dissolved to improve the heat resistance. May occur.

Copper (Cu) is added in the amount of 1 to 3% by weight for the precipitation strengthening effect during T6 heat treatment, especially when the addition of more than 3% by weight coarse intermetallic compound can be produced to limit the amount.

1 is a microstructure of the high heat-resistant alloy powder according to the present invention.

As can be seen in Figure 1, the alloy in the present invention is a fine and uniform distribution of spherical prismatic Si and intermetallic compound, even after sintering and T6 treatment to maintain the powdery structure without coarsening phenomenon at high temperature It is possible to provide a high heat-resistant aluminum powder alloy with improved fatigue properties.

Hereinafter, the embodiment of the present invention will be described in more detail with a comparative example, but the present invention is not limited to the following examples.

Examples and Comparative Examples

As an example and a comparative example, the present invention alloy and A4032 continuous casting alloy were used, and the results of the component ratio analysis are shown in Table 1 below.

Si Cu Fe Ni Ti Zr Comparative Example (A4032 Alloy) 12.1 1.2 0.3 1.1 0.06 0.05 Example 23.5 2.8 5.1- 0.15 0.11

The alloy according to the embodiment of the present invention has Al as a main component, and 23.5% by weight of Si, 2.8% by weight of Cu, 5.1% by weight of Fe, 0.15% by weight of Ti, and 0.11% by weight of Zr are added to the powder through atomization. After the production, the alloy is the result of sintering and T6 heat treatment.

On the other hand, the alloy (A4032) according to the comparative example has Al as a main component, and 12.1% by weight of Si, 1.2% by weight of Cu, 1.1% by weight of Ni, 0.06% by weight of Ti, and 0.05% by weight of Zr, after continuous casting The alloy of the result of T6 heat processing is shown.

Test Example

As a test example, changes in room temperature and high temperature strength of the above-described Example and Comparative Example alloys were measured by conventional equipment, and the results are shown in Table 2.

Room temperature High temperature (250 ° C) Tensile Strength (MPa) Elongation (%) Fatigue Strength (MPa) Comparative Example (A4032 Alloy) 370 2.8 65 MPa Example 450 1.3 100 MPa

As can be seen in Table 2, according to the embodiment of the present invention by a change in the microstructure, it was confirmed that a high-strength, high heat-resistant alloy material can be obtained compared to the existing alloy.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims to be described.

Claims (2)

In the high heat-resistant aluminum powder alloy for powder forging piston,
The main component is aluminum (Al), 20 to 25% by weight of silicon (Si), 4 to 6% by weight of iron (Fe), 1 to 3% by weight of copper (Cu), 0.3 to 0.7% by weight of manganese (Mn) and A high heat-resistant aluminum powder alloy produced by alloying by adding other alloying elements titanium (Ti) and zirconium (Zr), and then undergoing an atomization process.
The alloy of claim 1, wherein the titanium (Ti) is added at 0.15% by weight or less, and the zirconium (Zr) is added at 0.11% by weight or less.

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