Corrosion-resistant aluminum alloy

Abstract

An electronics module housing is provided. The electronics module housing includes a high-pressure die cast integrated power electronics (IPE) housing component having at least one coating-free mating surface. The integrated power electronics housing component is formed from an aluminum alloy including silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium more than 0 wt. % and less than 0.30 wt. %, and manganese more than 0 wt. % and than 0.15 wt. %.

Description

INTRODUCTION

[0001] The present disclosure relates to an electronics module housing, and more particularly, to an electronics module housing including an integrated part electronics (IPE) component formed of a corrosion-resistant aluminum alloy.

[0002] Aluminum exhibits a combination of high corrosion resistance, thermal conductivity, and machinability, and is thus a desirable material for use in the manufacture of electrical and vehicle components. Aluminum alloys for casting applications typically include silicon or other metals as alloying elements to increase strength and other desirable qualities.

[0003] Many metals and alloys, including aluminum, are affected by crevice corrosion, which is localized corrosion of a metal or alloy at or immediately adjacent to an area that is shielded from environmental exposure because of close proximity of the metal or alloy to a surface of another material or an adjacent surface of the same metal or alloy. Crevice corrosion is among the most damaging forms of corrosion.

[0004] Crevice geometries may be found on a wide variety of structures and components, for example flanges, threaded connections, lap joints, and under damaged coatings. For an electronics module housing, crevice corrosion tends to occur at sealing or mating surfaces. Current methods for improving crevice corrosion performance of aluminum-made electronics module housing include applying aluminum alloys with reduced copper content as it is believed that copper is the main alloying element that causes degraded corrosion performance. For instance, the copper content in A380 alloy ranges from 3-4 mass %, showing unsatisfactory performance in component-level crevice corrosion testing. However, commercially available premium aluminum alloys including A360 and 43400 alloys with reduced copper content of 0-0.6 wt. % and 0-0.08 wt. % still exhibit crevice corrosion. Hence, the known alloys are usually treated with anodization or an E-coat to pass the component-level crevice corrosion test, but the added coatings and anodization surface treatment increase cost.

[0005] While prior art methods and systems attempt to minimize crevice corrosion in aluminum and aluminum alloys and may achieve their particular purpose, a need still exists for a new and improved aluminum and aluminum alloy that minimizes and prevents crevice corrosion. Accordingly, a corrosion-resistant aluminum and aluminum alloy is needed.SUMMARY

[0006] According to several aspects of the present disclosure, an electronics module housing is provided. The electronics module housing includes a high-pressure die cast integrated power electronics (IPE) housing component having at least one coating-free mating surface. The integrated power electronics housing component is formed from an aluminum alloy including silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium less than 0.30 wt. %, and manganese than 0.15 wt. %.

[0007] In accordance with another aspect of the disclosure, the electronics module housing includes a corrosion rate (K) of the aluminum alloy less than or equal to 0.003.

[0008] In accordance with another aspect of the disclosure, the electronics module housing includes a corrosion rate (K) defined as K=−0.0251+0.0064 (Fe wt. %)+0.0844(Cu wt. %)+0.1041 (Cr wt. %).

[0009] In accordance with another aspect of the disclosure, the electronics module housing includes an aluminum alloy satisfying the equation 2.7 (Cr wt. %)+1.44 (Mn wt. %) +(Fe wt. %) is greater than 0.8.

[0010] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0011] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0012] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0013] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0014] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.05 wt. % and 0.10 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0015] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, iron between 0.25 wt. % and 0.65 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0016] In accordance with another aspect of the disclosure, the aluminum alloy includes copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

[0017] According to several aspects of the present disclosure, a method for forming a high-pressure die cast integrated power electronics (IPE) housing component is provided. The method includes forming an aluminum alloy in a molten state and casting the molten aluminum alloy by a high pressure die cast process to form a cast structure. The aluminum alloy includes silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium less than 0.30 wt. %, and manganese than 0.15 wt. %.

[0018] In accordance with another aspect of the disclosure, the cast structure is an individual IPE housing component, and each IPE housing component has at least one coating-free mating surface.

[0019] In accordance with another aspect of the disclosure, the method includes an aluminum alloy having a corrosion rate (K) less than or equal to 0.003.

[0020] In accordance with another aspect of the disclosure, the method includes an aluminum alloy having a corrosion rate (K) defined as K=−0.0251+0.0064 (Fe wt. %) +0.0844 (Cu wt. %)+0.1041 (Cr wt. %).

[0021] In accordance with another aspect of the disclosure, the aluminum alloy includes copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

[0022] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0023] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0024] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0025] According to several aspects of the present disclosure, an electronics module housing is provided. The electronics module housing includes a high-pressure die cast integrated power electronics (IPE) housing component having at least one coating-free mating surface. The integrated power electronics housing component is formed from an aluminum alloy including silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium less than 0.30 wt. %, and manganese than 0.15 wt. %. A corrosion rate (K) of the aluminum alloy is less than or equal to 0.003, where K=−0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %). Additionally, the aluminum alloy satisfies the equation 2.7 (Cr wt. %)+1.44 (Mn wt. %)+(Fe wt. %) is greater than 0.8%.

[0026] In accordance with another aspect of the disclosure, the electronics module housing includes an IPE housing component having a tensile yield strength between 160 MPa and 180 MPa and a tensile elongation-to-fracture of between 3%-6% in an as-cast state.

[0027] Further areas of applicability of the present disclosure will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

[0028] The above features and advantages, and other features and advantages, of the presently disclosed system and method are readily apparent from the detailed description, including the claims, and examples when taken in connection with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0030] FIG. 1 is an exploded perspective view illustrating an example of an electronics module housing including an integrated power electronics housing component having a coating-free mating surface formed from an aluminum alloy, in accordance with the present disclosure.

[0031] FIG. 2 is a graphical depiction of hydrogen evolution rates of six tested alloys shown in Table 1, in accordance with the present disclosure.

[0032] FIG. 3 is a flowchart illustrating a method for forming a high-pressure die cast integrated power electronics (IPE) housing component as shown in FIG. 1, in accordance with the present disclosure.DETAILED DESCRIPTION

[0033] Reference will now be made in detail to several examples of the disclosure that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0034] For electronics module housing, for example an integrated part electronics (IPE) component formed of a corrosion-resistant aluminum alloy, crevice corrosion tends to occur at sealing and mating surfaces. Many current aluminum alloys, including A360, A380, and premium 43400 alloys have been shown to fail crevice corrosion raising concerns for potential failure of electronic components.

[0035] FIG. 1 illustrates a perspective view of an electronics module housing 10, in accordance with the present disclosure. The electronics module housing 10 can include an integrated power electronics (IPE) housing component 12 formed from high pressure die casting, for example. An IPE module (not shown), housed within the integrated power electronics (IPE) housing component 12, includes an electric drive unit (EDU) or other electrical / mechanical modules that combine power electronics and motor components within a single assembly. The electronics module housing 10 and / or the integrated power electronics (IPE) housing component 12 can be utilized in automotive applications as well as high-performance computing, communications, and industrial systems.

[0036] The electronics module housing 10 is formed of an aluminum alloy and has at least one coating-free sealing or mating surface 14. A coating-free mating surface 14 includes a surface that is configured to abut a substrate or chassis, which supports the electronics module housing 10. For example, the coating-free mating surface 14 may include a lid 16 coupled to a wall 18, or a wall 18 coupled to a substrate 20. Preferably, the electronics module housing 10 includes no coating at any mating surface 14 of the housing 10.

[0037] Crevice corrosion performance of electronics module housing 10 can be evaluated via measuring corrosion penetration length on the mating surface 14, under designated testing environment.

[0038] The term “aluminum alloy” refers to a material that comprises, by weight, greater than or equal to 80% or, more preferably, greater than or equal to 90% aluminum (Al) and one or more other elements selected impart certain desirable properties to the material that are not exhibited by pure aluminum.

[0039] An aluminum alloy composition for casting shaped aluminum alloy parts may include, in addition to aluminum, alloying elements of silicon (Si), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), magnesium (Mg), chromium (Cr), and titanium (Ti). The respective amounts or Si, Cr, Cu, and Mg in the alloy are selected to provide the alloy with certain desirable properties during casting and with the ability to develop a desired microstructure during a subsequent heat treatment process.

[0040] The corrosion resistance of an aluminum alloy is strongly related to its alloying content. For example, the amount of silicon in the aluminum alloy is selected to provide the molten alloy with suitable fluidity for casting, a relatively low melting temperature, excellent dimensional stability, and low thermal expansion, all of which are required for excellent castability. In the aluminum alloys traditionally used for casting electronics module housing, such as A380, A360 and 43400 aluminum alloys, silicon content ranges from 9 mass % to 11 mass % for excellent castability. However, a higher silicon content, along with the existence of transition metal elements like iron (Fe), manganese (Mn), chromium (Cr) and copper (Cu), results in the formation of a larger volume of intermetallic particles embedded in the aluminum matrix which may act as cathode to induce corrosion of the aluminum matrix. Silicon content ranges from 6.5 mass % to 7.5 mass % will impart a better balance between castability and corrosion resistance for the application of electronics module housing.

[0041] In addition, the respective amounts of Fe, Cr, Cu, and Magnesium (Mg) in the aluminum alloy are selected to provide the alloy with the ability to develop a multiphase microstructure when subjected to a suitable heat treatment process that includes a solution heat treatment stage and a subsequent artificial aging heat treatment stage. Among them, Mg has relatively minor impact on corrosion resistance. The content of Mg is dependent on the requirement of strength properties and normally ranges from 0.1 mass % to 0.6 mass %. Fe, Cr and Cu will have significant adverse impacts on corrosion resistance. Moreover, allowing a higher content of Fe, Cr and Cu in aluminum alloy is often desirable as more low-cost scrap can be used in the production for cost-saving.

[0042] Additionally, elements not intentionally introduced into the composition of the aluminum alloy may be inherently present in the alloy in relatively small amounts (e.g., less than 0.2 wt. %, preferably less than 0.05 wt. %, and more preferably less than 0.01 wt. %). These elements may be present, for example, as impurities in the raw materials used to prepare the aluminum alloy. In examples where the aluminum alloy is referred to as comprising one or more alloying elements (e.g., one or more of Si, Cr, Cu, Mg, Ti, and / or Sr) and aluminum as balance, the term “as balance” does not exclude the presence of additional elements not intentionally introduced into the composition of the aluminum alloy but nonetheless inherently present in the aluminum alloy in relatively small amounts, for example as impurities.

[0043] For metals that have a low oxidation potential, including elemental aluminum, a cathodic reaction of hydrogen evolution is possible during free corrosion. In aluminum electronic housing components, hydrogen evolution indicates crevice corrosion of the aluminum housing components, often on or at mating or sealing surfaces. Crevice corrosion risk increases with active metal, improper crevice geometry, and component location. For evaluating crevice corrosion performance risk in a fast manner, hydrogen released from the corrosion of aluminum matrix was collected from a lab immersion test using samples of aluminum alloys with a size of 1 centimeter (cm)×1 cm×0.5 cm3 conducted in a 3.5 wt. % NaCl solution at room temperature for one week to determine an impact of iron (Fe), copper (Cu), and chromium (Cr) on corrosion resistance of the aluminum alloys. As shown in Table 1 below, six alloys were tested in a lab immersion test in which alloys A, B, C, D, E were Al-Si alloys containing 7 mass % Si and varied levels of Cr, Fe and Cu. A360 alloy was also tested as baseline. FIG. 2 illustrates the hydrogen evolution rates of the tested alloys. Hydrogen evolution rate can be calculated by linear fitting the data to get the slope for ranking corrosion resistance of various aluminum alloys. A smaller slope indicates a better corrosion resistance. According to the results, alloys E, A and D have better corrosion resistance than A360 alloy.TABLE 1Hydrogen evolutionAlloyrate (mL / cm2 · hour)B0.0241C0.0128A360 (baseline)0.0052E0.0030A0.0024D0.0019

[0044] A formula has been developed to correlate Cr, Cu and Fe contents of an aluminum alloy to its corrosion rate K in lab immersion test as K=−0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %), where Fe, Cu and Cr are mass percentages contained in the alloy.

[0045] Alloy E, as shown in Table 1 above, was selected to cast electronics module housing 10 for component-level crevice corrosion testing and passed with very limited crevice corrosion penetration at mating surfaces. When K ≤0.003 milliliters per square centimeter hour (ml / cm2·hr), the Al-Si-Cr-Fe-Cu alloy provides sufficient corrosion resistance for satisfying crevice corrosion performance for electronics module housing.

[0046] In an example, the aluminum alloy composition for casting shaped aluminum alloy parts has a hydrogen evolution rate K in lab immersion test of less than or equal to 0.0030 milliliters per square centimeter hour (mL / cm2·hr). In an additional example, the K satisfies the equation −0.0251+(0.0064·Fe·100)+(0.0844−Cu−100)+(0.1041·Cr·100), where Fe, Cu and Cr are weight and / or mass percentages contained in the alloy. In an additional example, which facilitates a high ratio of scrap in raw material production, the aluminum alloy includes equal to or greater than 0.05 wt. % copper (Cu) and equal to or greater than 0.2 wt. % iron (Fe).

[0047] In an example, the aluminum alloy may include, by weight, silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.5 wt. %, chromium more than 0 wt. % and less than 0.30 wt. %, and manganese more than 0 wt. % and less than 0.15 wt. %. For satisfying die-sticking resistance required by high pressure die casting process, 2.7·Cr·100+1.44·Mn·100+Fe>0.8, where Fe, Mn and Cr are mass percentages contained in the alloy.

[0048] In another example, the aluminum alloy may include, by weight, chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0049] In another example, the aluminum alloy may include, by weight, chromium between 0.1 wt. % and 0.15 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0050] In another example, the aluminum alloy may include, by weight, chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0051] In another example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0052] In another example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0053] In an example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0054] In an example, the aluminum alloy may include, by weight, chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0055] In an example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0056] In an example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0057] In an example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, iron between 0.25 wt. % and 0.65 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %. In an example, the aluminum alloy may include, by weight, copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

[0058] In an example, the electronics module housing 10 includes an IPE housing component or other component having a tensile yield strength between 160 MPa and 180 MPa and a tensile elongation-to-fracture between 3%-6% in an as-cast state.

[0059] With reference to FIG. 3, a method 100 for forming a high-pressure die cast integrated power electronics (IPE) housing component is presented, in accordance with the present disclosure. The method starts at block 102. Block 102 depicts forming an aluminum alloy in a molten state. Forming an aluminum alloy melt can include heating at least some of the alloying elements using, for example a furnace, to dissolve at least partially one or more of the alloying elements into the alloy melt. Then the alloy melt with designated chemistries will be cast into at least one (IPE) housing component 12. The raw materials used for preparing aluminum melt may include pure / refined aluminum and scrap aluminum. After casting, the IPE housing component may be subjected to cooling to different temperatures such that at least part of the alloying elements are retained in a supersaturated solid solution so that the aluminum alloy includes differing desired phases (e.g., an aluminum matrix phase, a dispersoid phase, and so forth). In an example, forming the aluminum alloy includes an aluminum alloy with silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium less than 0.30 wt. %, and manganese than 0.15 wt. %. Additionally, the aluminum alloy may include a hydrogen evolution rate K in lab immersion test less than or equal to 0.003, where K equals −0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %). In an additional example, to facilitate use of scrap metal in the raw materials for the aluminum alloy, the aluminum alloy can include copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

[0060] In an example, forming the aluminum alloy includes an aluminum alloy formed from alloying elements including chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0061] In an example, forming the aluminum alloy includes an aluminum alloy formed from alloying elements including chromium between 0.1 wt. % and 0.15 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0062] In an example, forming the aluminum alloy includes an aluminum alloy formed from alloying elements including chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0063] In an example, forming the aluminum alloy includes an aluminum alloy formed from alloying elements including chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0064] Block 104 depicts casting the molten aluminum alloy by a high pressure die cast process to form a cast structure. The cast structure includes an individual IPE housing component that has at least one coating-free mating surface. Casting the molten aluminum alloy can include using a high pressure die casting (HPDC) process. During HPDC, the aluminum-based melt (i.e., molten aluminum alloy composition) is injected with a die casting machine under force using considerable pressure into a steel mold or die to form components. A dosing furnace with a degassing system may be used to hold and transfer the molten aluminum alloy composition to the die casting machine. After the aluminum alloy composition solidifies to form the component, the cast component may be removed from the die. The component may then be further processed, for example with a heat treatment.

[0065] The aluminum alloy herein may be used to form a variety of casting structures including automobile parts, electronic housing parts, computer parts, communication parts, or consumer electronic parts.

[0066] The coating-free aluminum alloy and electronics module housing 10 of the present disclosure is advantageous and beneficial over prior art materials for use in power electronics sealing and mating interfaces, for example an IPE housing, as well as other aluminum alloy products. The aluminum alloy provides an alloy chemistry with an optimum balance between cost and corrosion resistance. The aluminum alloy satisfies requirements for crevice corrosion performance while accommodating a high ratio of scrap in raw materials for the aluminum alloy.

[0067] This description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims.

Examples

Embodiment Construction

[0033]Reference will now be made in detail to several examples of the disclosure that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0034]For electronics module housing, for example an integrated part electronics (IPE) component formed of a corrosion-resistant aluminum alloy, crevice corrosion tends to occur at sealing and mating surfaces. Many current aluminum alloys, including A360, A380, and premium 43400 alloys have been shown to fail crevice corrosion raising concerns for potential failure of electronic components.

[0035]FIG. 1 illustrates a perspective view of an electronics module housing 10, in accordance with the present disclosure. The electronics module housing 10 can include an integrated power electron...

INTRODUCTION

[0001] The present disclosure relates to an electronics module housing, and more particularly, to an electronics module housing including an integrated part electronics (IPE) component formed of a corrosion-resistant aluminum alloy.

[0002] Aluminum exhibits a combination of high corrosion resistance, thermal conductivity, and machinability, and is thus a desirable material for use in the manufacture of electrical and vehicle components. Aluminum alloys for casting applications typically include silicon or other metals as alloying elements to increase strength and other desirable qualities.

[0003] Many metals and alloys, including aluminum, are affected by crevice corrosion, which is localized corrosion of a metal or alloy at or immediately adjacent to an area that is shielded from environmental exposure because of close proximity of the metal or alloy to a surface of another material or an adjacent surface of the same metal or alloy. Crevice corrosion is among the most damaging forms of corrosion.

[0004] Crevice geometries may be found on a wide variety of structures and components, for example flanges, threaded connections, lap joints, and under damaged coatings. For an electronics module housing, crevice corrosion tends to occur at sealing or mating surfaces. Current methods for improving crevice corrosion performance of aluminum-made electronics module housing include applying aluminum alloys with reduced copper content as it is believed that copper is the main alloying element that causes degraded corrosion performance. For instance, the copper content in A380 alloy ranges from 3-4 mass %, showing unsatisfactory performance in component-level crevice corrosion testing. However, commercially available premium aluminum alloys including A360 and 43400 alloys with reduced copper content of 0-0.6 wt. % and 0-0.08 wt. % still exhibit crevice corrosion. Hence, the known alloys are usually treated with anodization or an E-coat to pass the component-level crevice corrosion test, but the added coatings and anodization surface treatment increase cost.

[0005] While prior art methods and systems attempt to minimize crevice corrosion in aluminum and aluminum alloys and may achieve their particular purpose, a need still exists for a new and improved aluminum and aluminum alloy that minimizes and prevents crevice corrosion. Accordingly, a corrosion-resistant aluminum and aluminum alloy is needed.SUMMARY

[0006] According to several aspects of the present disclosure, an electronics module housing is provided. The electronics module housing includes a high-pressure die cast integrated power electronics (IPE) housing component having at least one coating-free mating surface. The integrated power electronics housing component is formed from an aluminum alloy including silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium less than 0.30 wt. %, and manganese than 0.15 wt. %.

[0007] In accordance with another aspect of the disclosure, the electronics module housing includes a corrosion rate (K) of the aluminum alloy less than or equal to 0.003.

[0008] In accordance with another aspect of the disclosure, the electronics module housing includes a corrosion rate (K) defined as K=−0.0251+0.0064 (Fe wt. %)+0.0844(Cu wt. %)+0.1041 (Cr wt. %).

[0009] In accordance with another aspect of the disclosure, the electronics module housing includes an aluminum alloy satisfying the equation 2.7 (Cr wt. %)+1.44 (Mn wt. %) +(Fe wt. %) is greater than 0.8.

[0010] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0011] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0012] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0013] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0014] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.05 wt. % and 0.10 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0015] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, iron between 0.25 wt. % and 0.65 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0016] In accordance with another aspect of the disclosure, the aluminum alloy includes copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

[0017] According to several aspects of the present disclosure, a method for forming a high-pressure die cast integrated power electronics (IPE) housing component is provided. The method includes forming an aluminum alloy in a molten state and casting the molten aluminum alloy by a high pressure die cast process to form a cast structure. The aluminum alloy includes silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium less than 0.30 wt. %, and manganese than 0.15 wt. %.

[0018] In accordance with another aspect of the disclosure, the cast structure is an individual IPE housing component, and each IPE housing component has at least one coating-free mating surface.

[0019] In accordance with another aspect of the disclosure, the method includes an aluminum alloy having a corrosion rate (K) less than or equal to 0.003.

[0020] In accordance with another aspect of the disclosure, the method includes an aluminum alloy having a corrosion rate (K) defined as K=−0.0251+0.0064 (Fe wt. %) +0.0844 (Cu wt. %)+0.1041 (Cr wt. %).

[0021] In accordance with another aspect of the disclosure, the aluminum alloy includes copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

[0022] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0023] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0024] In accordance with another aspect of the disclosure, the aluminum alloy includes chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0025] According to several aspects of the present disclosure, an electronics module housing is provided. The electronics module housing includes a high-pressure die cast integrated power electronics (IPE) housing component having at least one coating-free mating surface. The integrated power electronics housing component is formed from an aluminum alloy including silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium less than 0.30 wt. %, and manganese than 0.15 wt. %. A corrosion rate (K) of the aluminum alloy is less than or equal to 0.003, where K=−0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %). Additionally, the aluminum alloy satisfies the equation 2.7 (Cr wt. %)+1.44 (Mn wt. %)+(Fe wt. %) is greater than 0.8%.

[0026] In accordance with another aspect of the disclosure, the electronics module housing includes an IPE housing component having a tensile yield strength between 160 MPa and 180 MPa and a tensile elongation-to-fracture of between 3%-6% in an as-cast state.

[0027] Further areas of applicability of the present disclosure will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

[0028] The above features and advantages, and other features and advantages, of the presently disclosed system and method are readily apparent from the detailed description, including the claims, and examples when taken in connection with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0030] FIG. 1 is an exploded perspective view illustrating an example of an electronics module housing including an integrated power electronics housing component having a coating-free mating surface formed from an aluminum alloy, in accordance with the present disclosure.

[0031] FIG. 2 is a graphical depiction of hydrogen evolution rates of six tested alloys shown in Table 1, in accordance with the present disclosure.

[0032] FIG. 3 is a flowchart illustrating a method for forming a high-pressure die cast integrated power electronics (IPE) housing component as shown in FIG. 1, in accordance with the present disclosure.DETAILED DESCRIPTION

[0033] Reference will now be made in detail to several examples of the disclosure that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0034] For electronics module housing, for example an integrated part electronics (IPE) component formed of a corrosion-resistant aluminum alloy, crevice corrosion tends to occur at sealing and mating surfaces. Many current aluminum alloys, including A360, A380, and premium 43400 alloys have been shown to fail crevice corrosion raising concerns for potential failure of electronic components.

[0035] FIG. 1 illustrates a perspective view of an electronics module housing 10, in accordance with the present disclosure. The electronics module housing 10 can include an integrated power electronics (IPE) housing component 12 formed from high pressure die casting, for example. An IPE module (not shown), housed within the integrated power electronics (IPE) housing component 12, includes an electric drive unit (EDU) or other electrical / mechanical modules that combine power electronics and motor components within a single assembly. The electronics module housing 10 and / or the integrated power electronics (IPE) housing component 12 can be utilized in automotive applications as well as high-performance computing, communications, and industrial systems.

[0036] The electronics module housing 10 is formed of an aluminum alloy and has at least one coating-free sealing or mating surface 14. A coating-free mating surface 14 includes a surface that is configured to abut a substrate or chassis, which supports the electronics module housing 10. For example, the coating-free mating surface 14 may include a lid 16 coupled to a wall 18, or a wall 18 coupled to a substrate 20. Preferably, the electronics module housing 10 includes no coating at any mating surface 14 of the housing 10.

[0037] Crevice corrosion performance of electronics module housing 10 can be evaluated via measuring corrosion penetration length on the mating surface 14, under designated testing environment.

[0038] The term “aluminum alloy” refers to a material that comprises, by weight, greater than or equal to 80% or, more preferably, greater than or equal to 90% aluminum (Al) and one or more other elements selected impart certain desirable properties to the material that are not exhibited by pure aluminum.

[0039] An aluminum alloy composition for casting shaped aluminum alloy parts may include, in addition to aluminum, alloying elements of silicon (Si), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), magnesium (Mg), chromium (Cr), and titanium (Ti). The respective amounts or Si, Cr, Cu, and Mg in the alloy are selected to provide the alloy with certain desirable properties during casting and with the ability to develop a desired microstructure during a subsequent heat treatment process.

[0040] The corrosion resistance of an aluminum alloy is strongly related to its alloying content. For example, the amount of silicon in the aluminum alloy is selected to provide the molten alloy with suitable fluidity for casting, a relatively low melting temperature, excellent dimensional stability, and low thermal expansion, all of which are required for excellent castability. In the aluminum alloys traditionally used for casting electronics module housing, such as A380, A360 and 43400 aluminum alloys, silicon content ranges from 9 mass % to 11 mass % for excellent castability. However, a higher silicon content, along with the existence of transition metal elements like iron (Fe), manganese (Mn), chromium (Cr) and copper (Cu), results in the formation of a larger volume of intermetallic particles embedded in the aluminum matrix which may act as cathode to induce corrosion of the aluminum matrix. Silicon content ranges from 6.5 mass % to 7.5 mass % will impart a better balance between castability and corrosion resistance for the application of electronics module housing.

[0041] In addition, the respective amounts of Fe, Cr, Cu, and Magnesium (Mg) in the aluminum alloy are selected to provide the alloy with the ability to develop a multiphase microstructure when subjected to a suitable heat treatment process that includes a solution heat treatment stage and a subsequent artificial aging heat treatment stage. Among them, Mg has relatively minor impact on corrosion resistance. The content of Mg is dependent on the requirement of strength properties and normally ranges from 0.1 mass % to 0.6 mass %. Fe, Cr and Cu will have significant adverse impacts on corrosion resistance. Moreover, allowing a higher content of Fe, Cr and Cu in aluminum alloy is often desirable as more low-cost scrap can be used in the production for cost-saving.

[0042] Additionally, elements not intentionally introduced into the composition of the aluminum alloy may be inherently present in the alloy in relatively small amounts (e.g., less than 0.2 wt. %, preferably less than 0.05 wt. %, and more preferably less than 0.01 wt. %). These elements may be present, for example, as impurities in the raw materials used to prepare the aluminum alloy. In examples where the aluminum alloy is referred to as comprising one or more alloying elements (e.g., one or more of Si, Cr, Cu, Mg, Ti, and / or Sr) and aluminum as balance, the term “as balance” does not exclude the presence of additional elements not intentionally introduced into the composition of the aluminum alloy but nonetheless inherently present in the aluminum alloy in relatively small amounts, for example as impurities.

[0043] For metals that have a low oxidation potential, including elemental aluminum, a cathodic reaction of hydrogen evolution is possible during free corrosion. In aluminum electronic housing components, hydrogen evolution indicates crevice corrosion of the aluminum housing components, often on or at mating or sealing surfaces. Crevice corrosion risk increases with active metal, improper crevice geometry, and component location. For evaluating crevice corrosion performance risk in a fast manner, hydrogen released from the corrosion of aluminum matrix was collected from a lab immersion test using samples of aluminum alloys with a size of 1 centimeter (cm)×1 cm×0.5 cm3 conducted in a 3.5 wt. % NaCl solution at room temperature for one week to determine an impact of iron (Fe), copper (Cu), and chromium (Cr) on corrosion resistance of the aluminum alloys. As shown in Table 1 below, six alloys were tested in a lab immersion test in which alloys A, B, C, D, E were Al-Si alloys containing 7 mass % Si and varied levels of Cr, Fe and Cu. A360 alloy was also tested as baseline. FIG. 2 illustrates the hydrogen evolution rates of the tested alloys. Hydrogen evolution rate can be calculated by linear fitting the data to get the slope for ranking corrosion resistance of various aluminum alloys. A smaller slope indicates a better corrosion resistance. According to the results, alloys E, A and D have better corrosion resistance than A360 alloy.TABLE 1Hydrogen evolutionAlloyrate (mL / cm2 · hour)B0.0241C0.0128A360 (baseline)0.0052E0.0030A0.0024D0.0019

[0044] A formula has been developed to correlate Cr, Cu and Fe contents of an aluminum alloy to its corrosion rate K in lab immersion test as K=−0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %), where Fe, Cu and Cr are mass percentages contained in the alloy.

[0045] Alloy E, as shown in Table 1 above, was selected to cast electronics module housing 10 for component-level crevice corrosion testing and passed with very limited crevice corrosion penetration at mating surfaces. When K ≤0.003 milliliters per square centimeter hour (ml / cm2·hr), the Al-Si-Cr-Fe-Cu alloy provides sufficient corrosion resistance for satisfying crevice corrosion performance for electronics module housing.

[0046] In an example, the aluminum alloy composition for casting shaped aluminum alloy parts has a hydrogen evolution rate K in lab immersion test of less than or equal to 0.0030 milliliters per square centimeter hour (mL / cm2·hr). In an additional example, the K satisfies the equation −0.0251+(0.0064·Fe·100)+(0.0844−Cu−100)+(0.1041·Cr·100), where Fe, Cu and Cr are weight and / or mass percentages contained in the alloy. In an additional example, which facilitates a high ratio of scrap in raw material production, the aluminum alloy includes equal to or greater than 0.05 wt. % copper (Cu) and equal to or greater than 0.2 wt. % iron (Fe).

[0047] In an example, the aluminum alloy may include, by weight, silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.5 wt. %, chromium more than 0 wt. % and less than 0.30 wt. %, and manganese more than 0 wt. % and less than 0.15 wt. %. For satisfying die-sticking resistance required by high pressure die casting process, 2.7·Cr·100+1.44·Mn·100+Fe>0.8, where Fe, Mn and Cr are mass percentages contained in the alloy.

[0048] In another example, the aluminum alloy may include, by weight, chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0049] In another example, the aluminum alloy may include, by weight, chromium between 0.1 wt. % and 0.15 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0050] In another example, the aluminum alloy may include, by weight, chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0051] In another example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0052] In another example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0053] In an example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0054] In an example, the aluminum alloy may include, by weight, chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0055] In an example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0056] In an example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0057] In an example, the aluminum alloy may include, by weight, chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, iron between 0.25 wt. % and 0.65 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %. In an example, the aluminum alloy may include, by weight, copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

[0058] In an example, the electronics module housing 10 includes an IPE housing component or other component having a tensile yield strength between 160 MPa and 180 MPa and a tensile elongation-to-fracture between 3%-6% in an as-cast state.

[0059] With reference to FIG. 3, a method 100 for forming a high-pressure die cast integrated power electronics (IPE) housing component is presented, in accordance with the present disclosure. The method starts at block 102. Block 102 depicts forming an aluminum alloy in a molten state. Forming an aluminum alloy melt can include heating at least some of the alloying elements using, for example a furnace, to dissolve at least partially one or more of the alloying elements into the alloy melt. Then the alloy melt with designated chemistries will be cast into at least one (IPE) housing component 12. The raw materials used for preparing aluminum melt may include pure / refined aluminum and scrap aluminum. After casting, the IPE housing component may be subjected to cooling to different temperatures such that at least part of the alloying elements are retained in a supersaturated solid solution so that the aluminum alloy includes differing desired phases (e.g., an aluminum matrix phase, a dispersoid phase, and so forth). In an example, forming the aluminum alloy includes an aluminum alloy with silicon between 6.5 wt. % and 7.5 wt. %, copper between 0.05 wt. % and 0.30 wt. %, magnesium between 0.1 wt. % and 0.6 wt. %, iron between 0.20 wt. % and 1.50 wt. %, chromium less than 0.30 wt. %, and manganese than 0.15 wt. %. Additionally, the aluminum alloy may include a hydrogen evolution rate K in lab immersion test less than or equal to 0.003, where K equals −0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %). In an additional example, to facilitate use of scrap metal in the raw materials for the aluminum alloy, the aluminum alloy can include copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

[0060] In an example, forming the aluminum alloy includes an aluminum alloy formed from alloying elements including chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0061] In an example, forming the aluminum alloy includes an aluminum alloy formed from alloying elements including chromium between 0.1 wt. % and 0.15 wt. %, manganese between 0.05 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, and iron between 0.2 wt. % and 0.60 wt. %.

[0062] In an example, forming the aluminum alloy includes an aluminum alloy formed from alloying elements including chromium between 0.1 wt. % and 0.15 wt. %, copper between 0.05 wt. % and 0.1 wt. %, iron between 0.25 wt. % and 0.60 wt. %, and magnesium between 0.5 wt. % and 0.6 wt. %.

[0063] In an example, forming the aluminum alloy includes an aluminum alloy formed from alloying elements including chromium between 0.05 wt. % and 0.10 wt. %, copper between 0.1 wt. % and 0.15 wt. %, and iron between 0.25 wt. % and 0.65 wt. %.

[0064] Block 104 depicts casting the molten aluminum alloy by a high pressure die cast process to form a cast structure. The cast structure includes an individual IPE housing component that has at least one coating-free mating surface. Casting the molten aluminum alloy can include using a high pressure die casting (HPDC) process. During HPDC, the aluminum-based melt (i.e., molten aluminum alloy composition) is injected with a die casting machine under force using considerable pressure into a steel mold or die to form components. A dosing furnace with a degassing system may be used to hold and transfer the molten aluminum alloy composition to the die casting machine. After the aluminum alloy composition solidifies to form the component, the cast component may be removed from the die. The component may then be further processed, for example with a heat treatment.

[0065] The aluminum alloy herein may be used to form a variety of casting structures including automobile parts, electronic housing parts, computer parts, communication parts, or consumer electronic parts.

[0066] The coating-free aluminum alloy and electronics module housing 10 of the present disclosure is advantageous and beneficial over prior art materials for use in power electronics sealing and mating interfaces, for example an IPE housing, as well as other aluminum alloy products. The aluminum alloy provides an alloy chemistry with an optimum balance between cost and corrosion resistance. The aluminum alloy satisfies requirements for crevice corrosion performance while accommodating a high ratio of scrap in raw materials for the aluminum alloy.

[0067] This description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims.

Examples

Embodiment Construction

[0033]Reference will now be made in detail to several examples of the disclosure that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0034]For electronics module housing, for example an integrated part electronics (IPE) component formed of a corrosion-resistant aluminum alloy, crevice corrosion tends to occur at sealing and mating surfaces. Many current aluminum alloys, including A360, A380, and premium 43400 alloys have been shown to fail crevice corrosion raising concerns for potential failure of electronic components.

[0035]FIG. 1 illustrates a perspective view of an electronics module housing 10, in accordance with the present disclosure. The electronics module housing 10 can include an integrated power electron...

Claims

1. An electronics module housing, comprising:a high-pressure die cast integrated power electronics (IPE) housing component having at least one coating-free mating surface, wherein the integrated power electronics housing component is formed from an aluminum alloy including:silicon between 6.5 wt. % and 7.5 wt. %;copper between 0.05 wt. % and 0.30 wt. %;magnesium between 0.1 wt. % and 0.6 wt. %;iron between 0.20 wt. % and 1.50 wt. %;chromium more than 0 wt. % and less than 0.30 wt. %; andmanganese more than 0 wt. % and less than 0.15 wt. %.

2. The electronics module housing of claim 1, wherein a corrosion rate (K) of the aluminum alloy is less than or equal to 0.003.

3. The electronics module housing of claim 2, wherein the corrosion rate (K) is defined as K=−0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %).

4. The electronics module housing of claim 1, wherein the aluminum alloy satisfies the equation 2.7 (Cr wt. %)+1.44 (Mn wt. %)+(Fe wt. %) is greater than 0.8%.

5. The electronics module housing of claim 1, wherein the aluminum alloy includes:chromium between 0.1 wt. % and 0.15 wt. %;copper between 0.05 wt. % and 0.1 wt. %; andiron between 0.2 wt. % and 0.60 wt. %.

6. The electronics module housing of claim 1, wherein the aluminum alloy includes:chromium between 0.1 wt. % and 0.15 wt. %;manganese between 0.05 wt. % and 0.15 wt. %;copper between 0.05 wt. % and 0.1 wt. %; andiron between 0.2 wt. % and 0.60 wt. %.

7. The electronics module housing of claim 1, wherein the aluminum alloy includes:chromium between 0.1 wt. % and 0.15 wt. %;copper between 0.05 wt. % and 0.1 wt. %;iron between 0.25 wt. % and 0.60 wt. %; andmagnesium between 0.5 wt. % and 0.6 wt. %.

8. The electronics module housing of claim 1, wherein the aluminum alloy includes:chromium between 0.05 wt. % and 0.10 wt. %;copper between 0.1 wt. % and 0.15 wt. %; andiron between 0.25 wt. % and 0.65 wt. %.

9. The electronics module housing of claim 1, wherein the aluminum alloy includes:chromium between 0.05 wt. % and 0.10 wt. %;manganese between 0.05 wt. % and 0.15 wt. %;copper between 0.1 wt. % and 0.15 wt. %; andiron between 0.25 wt. % and 0.65 wt. %.

10. The electronics module housing of claim 1, wherein the aluminum alloy includes:chromium between 0.05 wt. % and 0.10 wt. %;copper between 0.1 wt. % and 0.15 wt. %;iron between 0.25 wt. % and 0.65 wt. %; andmagnesium between 0.5 wt. % and 0.6 wt. %.

11. The electronics module housing of claim 1, wherein the aluminum alloy includes copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

12. A method for forming a high-pressure die cast integrated power electronics (IPE) housing component, comprising:forming an aluminum alloy in a molten state, the aluminum alloy including:silicon more than between 6.5 wt. % and 7.5 wt. %;copper between 0.05 wt. % and 0.30 wt. %;magnesium between 0.1 wt. % and 0.6 wt. %;iron between 0.20 wt. % and 1.50 wt. %;chromium more than 0 wt. % and less than 0.30 wt. %; andmanganese more than 0 wt. % and less than 0.15 wt. %; andcasting the molten aluminum alloy by a high pressure die cast process to form a cast structure, the cast structure being an individual IPE housing component, wherein each IPE housing component has at least one coating-free mating surface.

13. The method of claim 12, wherein a corrosion rate (K) of the aluminum alloy is less than or equal to 0.003.

14. The method of claim 13, wherein the corrosion rate (K) is defined as K=−0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %).

15. The method of claim 12, wherein the aluminum alloy includes copper greater than 0.05 wt. % and iron greater than 0.2 wt. %.

16. The method of claim 12, wherein the aluminum alloy includes:chromium between 0.1 wt. % and 0.15 wt. %;copper between 0.05 wt. % and 0.1 wt. %; andiron between 0.2 wt. % and 0.60 wt. %.

17. The method of claim 12, wherein the aluminum alloy includes:chromium between 0.1 wt. % and 0.15 wt. %;manganese between 0.05 wt. % and 0.15 wt. %;copper between 0.05 wt. % and 0.1 wt. %; andiron between 0.2 wt. % and 0.60 wt. %.

18. The method of claim 12, wherein the aluminum alloy includes:chromium between 0.1 wt. % and 0.15 wt. %;copper between 0.05 wt. % and 0.1 wt. %;iron between 0.25 wt. % and 0.60 wt. %; andmagnesium between 0.5 wt. % and 0.6 wt. %.

19. An electronics module housing, comprising:a high-pressure die cast integrated power electronics (IPE) housing component having at least one coating-free mating surface, wherein the integrated power electronics housing component is formed from an aluminum alloy including:silicon between 6.5 wt. % and 7.5 wt. %;copper between 0.05 wt. % and 0.30 wt. %;magnesium between 0.1 wt. % and 0.6 wt. %;iron between 0.20 wt. % and 1.50 wt. %;chromium more than 0 wt. % and less than 0.30 wt. %; andmanganese more than 0 wt. % and less than 0. 15 wt. %,wherein a corrosion rate (K) of the aluminum alloy is less than or equal to 0.003, wherein K=−0.0251+0.0064 (Fe wt. %)+0.0844 (Cu wt. %)+0.1041 (Cr wt. %), and wherein the aluminum alloy satisfies the equation 2.7 (Cr wt. %)+1.44 (Mn wt. %)+(Fe wt. %) is greater than 0.8%.

20. The electronics module housing of claim 19, wherein the IPE housing component has a tensile yield strength between 160 MPa and 180 MPa and a tensile elongation-to-fracture between 3%-6% in an as-cast state.

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