U.S. patent application number 11/990098 was filed with the patent office on 2010-07-01 for aluminum casting alloys.
This patent application is currently assigned to KSM Castings GmbH. Invention is credited to Andreas Buhrig-Polaczek, Andreas Hennings, Dietrich Kahn, Lars Wurker.
Application Number | 20100163137 11/990098 |
Document ID | / |
Family ID | 37517275 |
Filed Date | 2010-07-01 |
United States Patent
Application |
20100163137 |
Kind Code |
A1 |
Wurker; Lars ; et
al. |
July 1, 2010 |
Aluminum Casting Alloys
Abstract
The invention relates to a light metal alloy.
Inventors: |
Wurker; Lars; (Remscheid,
DE) ; Kahn; Dietrich; (Sehnde, DE) ; Hennings;
Andreas; (Aachen, DE) ; Buhrig-Polaczek; Andreas;
(Aachen, DE) |
Correspondence
Address: |
COLLARD & ROE, P.C.
1077 NORTHERN BOULEVARD
ROSLYN
NY
11576
US
|
Assignee: |
KSM Castings GmbH
|
Family ID: |
37517275 |
Appl. No.: |
11/990098 |
Filed: |
August 30, 2006 |
PCT Filed: |
August 30, 2006 |
PCT NO: |
PCT/DE2006/001525 |
371 Date: |
February 6, 2008 |
Current U.S.
Class: |
148/440 ;
148/437; 420/544; 420/546; 420/548 |
Current CPC
Class: |
C22C 21/04 20130101 |
Class at
Publication: |
148/440 ;
420/544; 420/546; 420/548; 148/437 |
International
Class: |
C22C 21/08 20060101
C22C021/08; C22C 21/06 20060101 C22C021/06; C22C 21/02 20060101
C22C021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2005 |
DE |
102005041188.6 |
Mar 6, 2006 |
DE |
102006010131.6 |
Claims
1. An Al casting alloy containing at least five of the following
alloying components: Si: 2.5 to 3.3, preferably 2.7 to 3.1 wt. %
Mg: 0.2 to 0.7, preferably 0.3 to 0.6 wt. % Fe: <0.18,
preferably 0.05 to 0.16 wt. % Mn: <0.5, preferably 0.05 to 0.4
wt. % Ti: <0.1, preferably 0.01 to 0.08 wt. % Sr: <0.03,
preferably 0.01 to 0.03 wt. % <0.03 wt. % Other: <0.1 wt. %
and in each case made up to 100 wt. % with Al.
2. The Al casting alloys according to claim 1, wherein the parts
cast therefrom are solution-annealed between 490 and 540.degree. C.
for 1 to 10 h.
3. The Al casting alloys according to claim 1, wherein the parts
cast therefrom are tempered between 150 and 200.degree. C. for 1 to
10 h.
4. The Al casting alloys according to claim 1, wherein the alloys
are grain-refined.
5. Use of Al casting alloys according to claim 1, wherein component
or parts for respectively chassis part of motor vehicles.
Description
[0001] The invention relates to aluminium casting alloys, in
particular for chassis applications. Generally used for this
purpose are primarily molten sub-eutectic AlSi alloys which are
alloyed with low Mg contents, e.g. AlSi7Mg or AlSi11Mg, to increase
the strength. In isolated cases AlSi(Mg, Cu) alloys are also used
but these can only have niche applications as a result of the
corrosive properties. The same applies to the family of AlCu(Ti,
Mg) alloys which offer the highest strengths among the common
alloys. Likewise, the AlMg alloys form niche applications in the
chassis sector. Other families of alloys such as AlZn or AlLi play
no role in chassis.
[0002] The components made of the aforesaid alloys are usually
subjected to a two-stage heat treatment to achieve the desired
properties.
[0003] The existing families of alloys generally have the
disadvantage that only a limited strength-strain ratio can be
achieved thereby. The aforesaid higher-strength alloys with added
Cu are frequently eliminated because of the corrosive properties.
AlMg alloys are significantly more difficult to pour and therefore
are limited in their application (component geometry).
[0004] Accordingly, it is the object of the invention to develop an
alloy having properties which still have sufficiently high breaking
elongation values at high material strengths, particularly for
applications in automobile construction. This combination of
properties is necessary, for example, in chassis applications in
order to be able to withstand cases of abuse. At the same time, the
alloy must be sufficiently pourable and should not impose any
excessively high requirements on the melting process and the metal
cycle on account of their composition.
[0005] This is achieved according to the invention by Al casting
alloys containing at least five of the following alloying
components:
[0006] Si: 2.5 to 3.3, preferably 2.7 to 3.1 wt. %
[0007] Mg: 0.2 to 0.7, preferably 0.3 to 0.6 wt. %
[0008] Fe: <0.18, preferably 0.05 to 0.16 wt. %
[0009] Mn: <0.5, preferably 0.05 to 0.4 wt. %
[0010] Ti: <0.1, preferably 0.01 to 0.08 wt. %
[0011] Sr: <0.03, preferably 0.01 to 0.03 wt. %
[0012] Other: <0.1 wt. %
[0013] and in each case made up to 100 wt. % with Al.
[0014] The alloys according to the invention have a strength-strain
ratio which cannot be achieved with conventional Al casting alloys
subject to the requirement of freedom from. Cu. In particular, in
pressure-assisted casting methods, e.g. low-pressure--back-pressure
chill casting, better mechanical technological properties are
obtained from the good casting structure.
[0015] it can also be advantageous if the alloy is
grain-refined.
[0016] In order to achieve or further develop the aforesaid
advantages, it is advantageous if the cast components are
heat-treated, in particular with the following parameters:
[0017] Solution annealing: 490 and 540.degree. C. for 1 to 10
h.
[0018] Tempering: 150 and 200.degree. C. for 1 to 10 h.
[0019] For some applications, however, it can also be advantageous
if only one single-stage tempering treatment is carried out,
generally known as, for example, T4, T5 or 0.
[0020] In addition to the aforesaid advantages exhibited by
components of alloys according to the invention, it is additionally
found that as a result of the lack of Cu and Cn alloying
constituents, the corrosion resistance is increased significantly.
The product is also relatively inexpensive because none of the
alloying additions such as, for example, rare earth metals which
make the product more expensive are used, the usual melting
treatment can be used and no particular expenditure is required for
separating circuits.
[0021] An excellent strength-strain ratio is also provided with
excellent pourability. Firstly, the pourability makes it possible
to achieve a casting free from major defects, known as blow holes
and secondly, the microstructure is positively influenced in such a
manner that the number of internal notches which reduce the
breaking elongation is kept as low as possible.
[0022] The following may be given as example values:
TABLE-US-00001 R.sub.m R.sub.p 0.2 A.sub.5 [MPa] [MPa] [%]
Gravitational chill casting 250 140 13 Casting state Gravitational
chill casting 320 260 5 Heat treatment T6 (540.degree. C., 7 h,
160.degree. C., 8 h) Pressure-assisted chill casting 370 300 11
Heat treatment T6 (540.degree. C., 7 h/160.degree. C., 6 h) *only
give the precise values when absolutely necessary
* * * * *