Internal combustion engine component and method for the production thereof

Abstract

Disclosed is an internal combustion engine component (1) comprising at least one area (4) that is subject to a greater thermal load then another area (5) during operation of the internal combustion engine. The area (4) that is subjected to a greater thermal load is provided with a lower heat expansion coefficient (α2) then the area (5) which is subject to a lower thermal load.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a national stage of PCT / EP2004 / 012413 filed Nov. 3, 2004 and based upon DE 103 53 473.3 filed on Nov. 15, 2003 under the International Convention.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention concerns a component of an internal combustion engine of the type defined in greater detail hereinafter. The invention further concerns a process for production of a component of an internal combustion engine. [0004] 2. Description of Related Art [0005] In components of internal combustion engines, such as, for example, cylinder heads or pistons, a problem frequently occurs during thermal cycling in that, in the case of prevention of thermal expansion in higher loaded areas, mechanical tensions are induced in these areas which are so high that, due to the strong plasticization and the therewith associated material fatigue in these areas, crack formation occurs. This prevention of thermal expans...

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Benefits of technology

[0007] It is thus the task of the present invention to provide a component of an internal combustion engine and a process for production thereof in which, even in the case of varying high thermal loads distributed across different areas of the component, the problems known from the state of the art with regard to the failure of the component can be avoided.

[0009] In accordance with the invention, the thermally highly loaded area of the component exhibits a lower thermal coefficient of expansion than the thermally less loaded area, which leads thereto, that the entire component can expand evenly during an increase in temperature. As a result thereof that the various areas of the inventive component expand evenly, there are smaller inhibitions in expansion, and thus smaller occurrence of the plastic deformation areas, so that upon heating and subsequent cooling essentially only small, or as the case may be, very minimal tensions are produced in the component, whereby the conventionally present danger of crack formation, attributable to the exceeding of the permissible tensions, is ultimately prevented.

[0010] By the inventive adaptation of the thermal coefficient of expansions to the thermal conditions within the component, the occurrence of a material fatiguing and / or a crack formation at a later point in time, or as the case may be, following higher loads, can be delayed, so that the inventive component can be employed in internal combustion engines with higher power and / or to lengthen the life span.

[0012] Therein the base material of the component is melted and an additive is introduced, which results in a changed thermal coefficient of expansion in the thermally higher loaded area. This manner of proceeding makes possible a particularly precise control of the alloy composition in the thermally higher loaded area.

Problems solved by technology

In components of internal combustion engines, such as, for example, cylinder heads or pistons, a problem frequently occurs during thermal cycling in that, in the case of prevention of thermal expansion in higher loaded areas, mechanical tensions are induced in these areas which are so high that, due to the strong plasticization and the therewith associated material fatigue in these areas, crack formation occurs.

Since the thermally higher loaded areas are generally in the middle of the component, an outwards expansion is not possible, and the result is the above mentioned tensions, in particular pressure tensions, which during the cooling process convert into contraction tensions, which can exceed the materials' strength.

These measures, however, extend evenly across the entire component, so that the above-described problems cannot be overcome by these measures.

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