Aluminum alloy, method for producing an engine component, engine component, and use of an aluminum alloy to produce an engine component

Abstract

An aluminum alloy, and in particular a cast aluminum alloy, for producing an engine component, in particular a piston for an internal combustion engine, consists of the following alloying elements: Silicon: 10% by weight to <13% by weight, nickel: to <0.6% by weight, copper: 1.5% by weight to <3.6% by weight, magnesium: 0.5% by weight to 1.5% by weight, iron: 0.1% by weight to 0.7% by weight, manganese: 0.1 to 0.4% by weight, zirconium: >0.1 to <0.3% by weight, vanadium: >0.08 to <0.2% by weight, titanium: 0.05 to <0.2% by weight, phosphorus: 0.0025 to 0.008% by weight, and as balance aluminum and unavoidable impurities.

Claims

1. A method for producing an engine component, comprising gravity casting an aluminum alloy consisting of the following alloy elements: silicon: 11% by weight to <12.5% by weight, copper: 1.8% by weight to <2.6% by weight, magnesium: 0.8% by weight to 1.2% by weight, iron: 0.4% by weight to 0.6% by weight, manganese: 0.1 to 0.4% by weight, zirconium: >0.1 to <0.3% by weight, vanadium: >0.08 to <0.2% by weight, titanium: 0.05 to <0.2% by weight, phosphorus: 0.0025 to 0.008% by weight, and as balance aluminum and unavoidable impurities, wherein a ratio of the iron to the manganese is between 2:1 to 5:1, and the sum of the iron and the manganese does not exceed 0.9% by weight.

2. The method of claim 1, wherein the engine component produced by the method is a piston for an internal combustion engine.

Description

SUMMARY

(1) An aluminum alloy is provided that can be cast by gravity die casting, has a low density and nevertheless contains an increased proportion of finely dispersed, highly heat-resistant, thermally stable phases.

(2) As with pressure die casting, there is also an upper concentration limit for gravity die casting up to which alloying elements should be introduced and above which the castability of the alloy is made difficult or impossible. Moreover, too high concentrations of strength-increasing elements result in the formation of large plate-shaped intermetallic phases that drastically reduce fatigue strength. This is taken into account in the present invention.

(3) An aluminum alloy, in particular a cast aluminum alloy, containing the alloying elements silicon (Si): 10.0% by weight to <13.0% by weight, nickel (Ni): to <0.6% by weight, copper (Cu): 1.5% by weight to <3.6% by weight, magnesium (Mg): 0.5% by weight to 1.5% by weight, iron (Fe): 0.1% by weight to 0.7% by weight, manganese (Mn): 0.1 to 0.4% by weight, zirconium (Zr): >0.1 to <0.3% by weight, vanadium (V): >0.08 to <0.2% by weight, titanium (Ti): 0.05 to <0.2% by weight, phosphorus (P): 0.0025 to 0.008% by weight,
and as balance aluminum and unavoidable impurities, or optionally consisting thereof, and thus furthermore having particularly favorable properties as regards heat resistance and, on account of reduced density compared to the prior art, being suitable for the production of weight-reduced and heavy-duty pistons for internal combustion engines. Preferably, the aluminum alloy according to the invention is nickel-free and therefore does not contain significant amounts of nickel (Ni).

(4) The contents of copper and nickel that are significantly reduced compared to the prior art on the one hand advantageously reduce the overall costs of alloy production since they are among the most expensive alloying elements, and thus any (partial) substitution or reduction in the contents of these two elements results in considerable cost savings. On the other hand, this reduces the density of the aluminum material. The present invention is characterized by the fact that owing to the optimum adjustment of the alloying elements magnesium, iron, manganese, zirconium, vanadium and titanium, good and sufficient strength is nevertheless ensured despite the significant reduction in the contents of the elements copper and nickel that are otherwise necessary to withstand high thermal stresses. The silicon content according to the invention serves to achieve good castability of the aluminum material.

(5) The above alloy according to the invention preferably consists of the listed components and contains only the listed components and otherwise only unavoidable impurities, i.e. components in low concentration that have not been deliberately added as functional components. The alloy according to the invention is then preferably free of further elements and in particular free of beryllium (Be) and/or calcium (Ca).

(6) Furthermore, it is preferred that the aluminum alloy or cast aluminum alloy according to the invention contains 11.0 to <12.5 silicon and/or 1.8 to <2.6% by weight copper and/or 0.8% by weight to 1.2% by weight magnesium and/or 0.4% by weight to 0.6% by weight iron. Advantageously, the aluminum alloy or cast aluminum alloy according to the invention has an iron/manganese ratio of 2:1 and preferably between 2:1 and 5:1 and/or a sum of the contents of iron and manganese not exceeding 0.9% by weight.

(7) The discovered aluminum alloy is advantageously produced or processed according to the invention using the gravity die casting method.

(8) An engine component according to the invention, in particular a piston for an internal combustion engine, preferably consists at least partially of one of the aforementioned aluminum alloys according to the invention. Such an engine component according to the invention has a high heat resistance. In a piston produced in accordance with the invention, there is furthermore only a small amount of primary silicon and silicon precipitates of acceptable size in the thermally highly stressed bowl rim area or bottom area thereof, and thus the alloy leads in particular to a very high heat resistance of a piston produced in accordance with the invention.

(9) A further aspect of the invention is the preferred use of the aluminum alloy according to the invention as described above for the production of an engine component, in particular a piston of an internal combustion engine.