U.S. patent application number 12/483187 was filed with the patent office on 2009-12-24 for cast component and method for the production thereof.
This patent application is currently assigned to BDW TECHNOLOGIES GMBH. Invention is credited to Richard Weizenbeck, Dirk E.O. Westerheide, Juergen Wuest.
Application Number | 20090314392 12/483187 |
Document ID | / |
Family ID | 41165361 |
Filed Date | 2009-12-24 |
United States Patent
Application |
20090314392 |
Kind Code |
A1 |
Wuest; Juergen ; et
al. |
December 24, 2009 |
CAST COMPONENT AND METHOD FOR THE PRODUCTION THEREOF
Abstract
The invention relates to a method for the production of a cast
component made of an aluminium diecasting alloy, in which the cast
component is subjected to a heat treatment process after casting,
wherein an aluminium diecasting alloy is used, by means of which
the cast component has an elongation at break A.sub.5 of
.gtoreq.10% and a yield point Rp.sub.0.2 of <120 MPa, and
wherein a single-step annealing process for stability is carried
out at a temperature of 120-260.degree. C., after which the
heat-treated cast component has a break at elongation A.sub.5 of
.gtoreq.7% and a yield point Rp.sub.0.2 of .gtoreq.110 MPa.
Furthermore, the invention relates to a cast component which is
produced in accordance with a method of this type.
Inventors: |
Wuest; Juergen; (Erding,
DE) ; Weizenbeck; Richard; (Erding, DE) ;
Westerheide; Dirk E.O.; (Versmold, DE) |
Correspondence
Address: |
BARLOW, JOSEPHS & HOLMES, LTD.
101 DYER STREET, 5TH FLOOR
PROVIDENCE
RI
02903
US
|
Assignee: |
BDW TECHNOLOGIES GMBH
Markt Schwaben
DE
|
Family ID: |
41165361 |
Appl. No.: |
12/483187 |
Filed: |
June 11, 2009 |
Current U.S.
Class: |
148/549 ;
148/437; 148/440 |
Current CPC
Class: |
C22C 21/02 20130101;
C22F 1/043 20130101 |
Class at
Publication: |
148/549 ;
148/437; 148/440 |
International
Class: |
C22F 1/04 20060101
C22F001/04; C22C 21/00 20060101 C22C021/00; C22C 21/06 20060101
C22C021/06; C22C 21/02 20060101 C22C021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 24, 2008 |
DE |
10 2008 029 864.6 |
Claims
1. Method for producing a cast component made of an aluminium
diecasting alloy, in which the cast component is subjected to a
heat treatment process after casting, characterised in that an
aluminium diecasting alloy is used, by means of which the cast
component, as cast, has an elongation at break A.sub.5 of
.gtoreq.10% and a yield point RP.sub.0.2 of <120 MPa, and in
that an annealing process for stability is carried out at a
temperature of 120-260.degree. C., after which the heat-treated
cast component has an elongation at break A.sub.5 of .gtoreq.7% and
a yield point Rp.sub.0.2 of .gtoreq.110 MPa.
2. Method according to claim 1, characterised in that an aluminium
diecasting alloy with <8.5% by weight, and in particular
.ltoreq.8.3% by weight silicon is used
3. Method according to claim 1, characterised in that an aluminium
diecasting alloy with <0.6% by weight, and in particular
0.02-0.3% by weight magnesium is used.
4. Method according to claim 1, characterised in that an aluminium
diecasting alloy with the following alloy elements is used:
TABLE-US-00006 4 to 8.2 % by weight silicon 0.5 to 0.6 % by weight
manganese 0.15 to 0.2 % by weight iron 0.04 to 0.2 % by weight
magnesium 0.04 to 0.08 % by weight titanium 14 * 10.sup.-3 to 18 *
10.sup.-3 % by weight strontium (140-180 ppm)
and the rest being formed of aluminium, which individually contains
a maximum of 0.05% and a total maximum of 0.2% by weight impurities
caused by the production method.
5. Method according to claim 1, characterised in that an aluminium
diecasting alloy is used, by means of which the cast component, as
cast, has an elongation at break A.sub.5 of .gtoreq.11%, and in
particular of .gtoreq.12%.
6. Method according to of claim 1, characterised in that an
aluminium diecasting alloy is used, by means of which the cast
component, as cast, has an elongation at break A.sub.5 of
.gtoreq.13%.
7. Method according to claim 1, characterised in that an aluminium
diecasting alloy is used, by means of which the cast component, as
cast, has a yield point Rp.sub.0.2 of .gtoreq.105, and in
particular of .gtoreq.110 MPa.
8. Method according to claim 1, characterised in that an aluminium
diecasting alloy is used, by means of which the cast component, as
cast, has a yield point Rp.sub.0.2 of .gtoreq.115, and in
particular of .gtoreq.120 MPa.
9. Method according to claim 1, characterised in that the annealing
process for stability is carried out at a temperature of
200-240.degree. C.
10. Method according to claim 1, characterised in that the
annealing process for stability is carried out, after which the
heat-treated cast component has a yield point Rp.sub.0.2 of
.gtoreq.115 to .ltoreq.165 MPa, and in particular .gtoreq.125 to
.ltoreq.220 MPa.
11. Cast component made of an aluminium diecasting alloy and
subjected to a heat treatment process after casting, characterised
in that the cast component is formed from an aluminium diecasting
alloy which, as cast, has an elongation at break A.sub.5 of
.gtoreq.10% and a yield point Rp.sub.0.2 of <120 MPa, in that
the cast component is subjected to an annealing process for
stability at a temperature of 120-260.degree. C., after which the
heat-treated cast component has a break at elongation A.sub.5 of
.gtoreq.7% and a yield point Rp.sub.0.2 of .gtoreq.110 MPa.
12. Cast component according to claim 11, characterised in that the
aluminium diecasting alloy of the cast component comprises <8.5%
by weight, and in particular .ltoreq.8.3% by weight silicon.
13. Cast component according to claim 11, characterised in that the
aluminium diecasting alloy of the cast component comprises <0.6%
by weight, and in particular 0.02-0.3% by weight magnesium.
14. Cast component according to claim 11, characterised in that the
aluminium diecasting alloy of the cast component comprises the
following alloy elements: TABLE-US-00007 4 to 8.2 % by weight
silicon 0.5 to 0.6 % by weight manganese 0.15 to 0.2 % by weight
iron 0.04 to 0.2 % by weight magnesium 0.04 to 0.08 % by weight
titanium 14 * 10.sup.-3 to 18 * 10.sup.-3 % by weight strontium
(140-180 ppm)
and the rest being formed of aluminium, which individually contains
a maximum of 0.05% and a total maximum of 0.2% by weight impurities
caused by the production method.
15. Cast component according to claim 11, characterised in that the
cast component, as cast, has an elongation at break A.sub.5 of
.gtoreq.11%, and in particular of .gtoreq.12%.
16. Cast component according to claim 11, characterised in that the
cast component, as cast, has an elongation at break A.sub.5 of
.gtoreq.13%.
17. Cast component according to claim 11, characterised in that the
cast component, as cast, has a yield point Rp.sub.0.2 of
.gtoreq.105, and in particular of .gtoreq.110 MPa.
18. Cast component according to claim 11, characterised in that the
cast component, as cast, has a yield point Rp.sub.0.2 of
.gtoreq.115, and in particular of .gtoreq.120 MPa.
19. Cast component according to claim 11, characterised in that the
cast component is subjected to an annealing process for stability
at a temperature of 200-240 .degree. C.
20. Cast component according to claim 11, characterised in that the
heat-treated cast component has a yield point Rp.sub.0.2 of
.gtoreq.115 to .ltoreq.220 MPa, and in particular
.gtoreq.125.ltoreq.165 MPa.
Description
[0001] The present invention relates to a method for producing a
cast component made of an aluminium diecasting alloy of the type
disclosed in the preamble of claim 1. The invention further relates
to a cast component made of an aluminium diecasting alloy of the
type disclosed in the preamble of claim 11.
[0002] In order for cast components of this type made of aluminium
diecasting alloys to be used, for example, in the automobile
industry, they are currently normally subjected to a heat treatment
process after primary forming and casting.
[0003] As a result of this heat treatment a cast component is
produced, by means of which short-term heat stability at
205.degree. C. over a period of 1 hour, for example, or long-term
heat stability at 150.degree. C. over a period of 1,000 hours, for
example, may be achieved. In this case, short-term heat stability
is necessary for the car body to be appropriately heat-stable, for
example, when baking on a layer of paint, this process taking place
over 20 mins at 170.degree. C. for example. Long-term heat
stability is necessary, for example, so the components can
withstand corresponding temperatures which are emitted by the
motor, for example during vehicle operation, or which act on the
components by way of solar radiation.
[0004] In this case, crash-sustainable cast components with reduced
ductility may be produced, for example, which have a yield point
Rp.sub.0.2 of, for example, between 120 and 165 MPa and an
elongation at break A.sub.5 of .gtoreq.7%. Corresponding components
with a suitable level of ductility are thus produced and may be
used, for example, in the region of a deformable zone.
[0005] Nowadays, in order to be able to produce these components,
alloys must be used, for example, which contain a high proportion
of the alloy elements Ti, Zr and Mo. However, these alloy elements
are extremely expensive and therefore the cast components are
ultimately also very expensive.
[0006] The object of the present invention is therefore to provide
a method and a cast component of the aforementioned type, by means
of which cost-effective production can be achieved.
[0007] This object is achieved in accordance with the invention by
a method and cast component having the features of claims 1 and 11.
Advantageous embodiments with useful and non-trivial developments
of the invention are disclosed in the respective dependent
claims.
[0008] In order to provide a method by means of which cast
components with an elongation at break A.sub.5 of .gtoreq.7% and a
yield point Rp.sub.0.2 of .gtoreq.110 MPa can be produced as
cost-effectively as possible, it is provided in accordance with the
invention to use an aluminium diecasting alloy, by means of which
the cast component, as cast, has an elongation at break A.sub.5 of
.gtoreq.10% and a yield point Rp.sub.0.2 of <120 MPa, the cast
component being subjected to an annealing process for stability at
a temperature of 120 to 260.degree. C. after primary forming. By
way of the said annealing process for stability, a correspondingly
suitable aluminium diecasting alloy may thus be used in a simple
manner so sufficient values are still obtained after the heat
treatment.
[0009] These sufficient values are necessary to produce aluminium
diecasting components having suitable properties so they can be
used, for example in the region of deformable zones, within the
field of automobile manufacture. As is comprised within the scope
of the invention, it should also be noted, however, that the
present cast component is in no way limited to use within the
region of deformable zones of a motor vehicle. The present cast
component may also be used at other locations, for example in the
region of the chassis or in the region of external attaching parts
or components.
[0010] The present invention makes it possible to achieve a
sufficient level of heat stability of the cast component in a
simple manner in such a way that said component remains heat-stable
in the short-term for 1 hour at 205.degree. C. and in the long-term
for 1,000 hours at 150.degree. C. without any significant change to
the mechanical properties, such as the elongation at break A.sub.5
and the yield point Rp.sub.0.2.
[0011] A particularly cost-effective aluminium diecasting alloy can
thus be produced which comprises <8.5% by weight, and in
particular .ltoreq.8.3% by weight silicon. This reduced silicon
content in the diecasting alloy may, in particular, be compensated
by an optimised content of magnesium.
[0012] In a further embodiment of the invention it has proved to be
advantageous if the magnesium content is <0.6% by weight, and in
particular ranges from 0.02 to 0.3% by weight. The aforementioned
properties of the aluminium diecasting alloy thus enable production
which is as cost-effective as possible, in which the necessary
values of the cast component, in particular after heat treatment,
are attained without having to add a considerable amount of Ti, Zr
or Mo for example.
[0013] In a further embodiment of the invention, it has also proved
to be advantageous if an aluminium diecasting alloy having the
following alloy elements is used:
TABLE-US-00001 4 to 8.2 % by weight silicon 0.5 to 0.6 % by weight
manganese 0.15 to 0.2 % by weight iron 0.04 to 0.2 % by weight
magnesium 0.04 to 0.08 % by weight titanium 14 * 10.sup.-3 to 18 *
10.sup.-3 % by weight strontium (140-180 ppm)
and the rest being formed of aluminium, which individually contains
a maximum of 0.05% and a total maximum of 0.2% by weight impurities
caused by the production method.
[0014] An aluminium diecasting alloy of this type is thus
characterised not only by an extremely low silicon content and an
optimised magnesium content, but in particular in that the alloy
elements Ti, Zr and Mo can be dispensed with in most cases. These
alloy elements in particular are influential, namely since they
drive up the price of aluminium diecasting alloys.
[0015] In a further embodiment of the invention it has also proved
to be advantageous if an aluminium diecasting alloy is used, by
means of which the cast component, as cast, has an elongation at
break A.sub.5 of .gtoreq.11%, and in particular .gtoreq.12%. It
should thus be ensured that the cast component also has a
sufficient elongation at break A.sub.5 of .gtoreq.7% after the heat
treatment or annealing process for stability.
[0016] In order to produce a cast component which has a
particularly advantageous elongation at break A.sub.5, even after
the heat treatment, an aluminium diecasting alloy is preferably
used, by means of which the cast component, as cast, has an
elongation at break A.sub.5 of .gtoreq.13%.
[0017] It is further advantageous to use an aluminium diecasting
alloy, by means of which the cast component, as cast, has a yield
point Rp.sub.0.2 of .gtoreq.105, and in particular of .gtoreq.110
MPa. Starting from this yield point Rp.sub.0.2 it is thus possible
to achieve a required yield point Rp.sub.0.2 of .gtoreq.120 MPa
after heat treatment in a simple manner.
[0018] In order to obtain an even higher yield point after the
annealing process for stability, it has also proved advantageous to
set the magnesium content of the aluminium diecasting alloy within
a range of up to 0.6% by weight at most, the cast component, as
cast, comprising a yield point Rp.sub.0.2 of .gtoreq.80 and in
particular of .gtoreq.85 MPa.
[0019] In a further embodiment of the invention, it has also proved
advantageous if the annealing process for stability is carried out
at a temperature of 200 to 240.degree. C. It is thus possible to
achieve a particularly quick annealing process, the duration of
which is, for example, <180 mins, and in particular <60
mins.
[0020] In particular, the annealing process for stability is
ultimately carried out in such a way that the heat-treated cast
component subsequently has a yield point Rp.sub.0.2 of .gtoreq.115
to .ltoreq.220 MPa, and in particular .gtoreq.125 to .ltoreq.165
MPa. Particularly advantageous components may thus be obtained
which, for example, may be used in the body work of passenger
vehicles.
[0021] Of course, the aforementioned advantages discussed in
conjunction with the method according to the invention also apply
to the cast component according to claim 11.
[0022] Further advantages, features and details of the invention
will be disclosed in the following description of preferred
embodiments.
EXAMPLE 1
[0023] In accordance with Example 1, an aluminium diecasting alloy
is used which comprises the following alloy elements:
TABLE-US-00002 7.8 to 8.2 % by weight silicon 0.5 to 0.6 % by
weight manganese 0.15 to 0.2 % by weight iron 0.04 to 0.08 % by
weight magnesium 0.04 to 0.08 % by weight titanium 14 * 10.sup.-3
to 18 * 10.sup.-3 % by weight strontium (140-180 ppm)
and the rest being formed of aluminium, which individually contains
a maximum of 0.05% and a total maximum of 0.2% by weight impurities
caused by the production method.
[0024] This aluminium diecasting alloy is characterised in that it
has a break at elongation A.sub.5 of .gtoreq.10% and a yield point
Rp.sub.0.2 of <120 MPa after the cast component has been cast or
primary formed and is immediately in the cast state.
[0025] The components produced from the aforementioned aluminium
diecasting alloy are subsequently subjected to an annealing process
for stability at between 120 and 260.degree. C., and in particular
between 200 to 240.degree. C. for a duration of <180 mins, for
example approximately 20 mins to 90 mins, and in particular for a
duration of 30 mins to 60 mins.
[0026] After the heat treatment, the cast component has a yield
point Rp.sub.0.2 of, for example, approximately 110 to 120 MPa, and
in particular between 115 to 118 MPa.
EXAMPLE 2
[0027] According to Example 2, an aluminium diecasting alloy for
the cast components is used, which has the following alloy
elements:
TABLE-US-00003 7.8 to 8.2 % by weight silicon 0.5 to 0.6 % by
weight manganese 0.15 to 0.2 % by weight titanium 0.08 to 0.12 % by
weight magnesium 0.04 to 0.08 % by weight titanium 14 * 10.sup.-3
to 18 * 10.sup.-3 % by weight strontium (140-180 ppm)
and the rest being formed of aluminium, which individually contains
a maximum of 0.05% and a total maximum of 0.2% by weight impurities
caused by the production method.
[0028] The aluminium diecasting alloy used in this case has an
elongation at break A.sub.5 of .gtoreq.10% and a yield point
Rp.sub.0.2 of <120 MPa as cast.
[0029] The respective cast component as cast is subsequently
subjected to an annealing process for stability at a temperature
of, for example, approximately 120 to 260.degree. C., and in
particular at a temperature of 200 to 240.degree. C. within a
period of <180 mins, for example approximately 20 mins to
approximately 90 mins, and in particular within a period of
approximately 30 mins to approximately 60 mins.
[0030] The cast component subsequently has an elongation at break
A.sub.5 of .gtoreq.7% and a yield point of Rp.sub.0.2, for example,
approximately 125 to 135 MPa, and in particular of 129 to 133
MPa.
EXAMPLE 3
[0031] According to Example 3, an aluminium diecasting alloy for
the respective cast component is used which comprises the following
alloy elements:
TABLE-US-00004 7.8 to 8.2 % by weight silicon 0.5 to 0.6 % by
weight manganese 0.15 to 0.2 % by weight iron 0.12 to 0.16 % by
weight magnesium 0.04 to 0.08 % by weight titanium 14 * 10.sup.-3
to 18 * 10.sup.-3 % by weight strontium (140-180 ppm)
and the rest being formed of aluminium, which individually contains
a maximum of 0.05% and a total maximum of 0.2% by weight impurities
caused by the production method.
[0032] The cast components produced using the aforementioned
aluminium diecasting alloy have an elongation at break A.sub.5 of
.gtoreq.10% and a yield point Rp.sub.0.2 of <120 MPa as cast,
i.e. before any heat treatment.
[0033] The individual cast components are in turn subjected to an
annealing process for stability carried out at a temperature
ranging from 120 to 260.degree. C., and in particular from 200 to
240.degree. C. The annealing process for stability is carried out
over a period of up to 180 mins, and in this case, for example,
approximately 20 mins to 90 mins, and in particular over a period
from 30 to 60 mins.
[0034] The cast components heat-treated in this manner have, after
the annealing process for stability, an elongation at break A.sub.5
of .gtoreq.7% and a yield point Rp.sub.0.2 ranging between 135 and
150 MPa, and in particular ranging from 141 to 148 MPa.
EXAMPLE 4
[0035] According to Example 4, an aluminium diecasting alloy is
used which comprises the following alloy elements:
TABLE-US-00005 7.8 to 8.2 % by weight silicon 0.5 to 0.6 % by
weight manganese 0.15 to 0.2 % by weight iron 0.16 to 0.2 % by
weight magnesium 0.04 to 0.08 % by weight titanium 14 * 10.sup.-3
to 18 * 10.sup.-3 % by weight strontium (140-180 ppm)
and the rest being formed of aluminium, which individually contains
a maximum of 0.05% and a total maximum of 0.2% by weight impurities
caused by the production method.
[0036] In the present case also, the cast components produced by
the aforementioned aluminium diecasting alloy comprise a elongation
at break A.sub.5 of .gtoreq.7% and a yield point Rp.sub.0.2 of
<120 MPa as cast and before the heat treatment.
[0037] The cast components are in turn subjected to an annealing
process for stability at a temperature of 120 to 260.degree. C.,
and in particular between 200 and 240.degree. C. The annealing
process for stability is thus carried out within a period lasting
up to 180 mins, in particular lasting between 20 mins and 90 mins,
and in particular within a period lasting between 30 mins and 60
mins.
[0038] In the present case, cast components are thus produced
which, after the heat treatment, have a break at elongation A.sub.5
of .gtoreq.7% and a yield point Rp.sub.0.2 ranging from 145 to 165
MPa, and in particular ranging from 151 to 161 MPa.
SUMMARY
[0039] All in all, it can thus be seen from the above Examples 1 to
4 that, in the present case, starting from respective cast
components which have an elongation at break A.sub.5 of .gtoreq.10%
and a yield point Rp.sub.0.2 of <120 MPa as cast and before heat
treatment, heat-treated cast components can be produced by way of a
suitable annealing process for stability, which cast components
subsequently have an elongation at break A.sub.5 of .gtoreq.7% and
a yield point Rp.sub.0.2 of .gtoreq.110 MPa.
[0040] It can further be seen that, by adjusting the magnesium
content, the yield point can be adjusted to the values given
according to Examples 1 to 4, depending on the field in which the
respective cast component is to be used. For a high yield point,
magnesium content may be adjusted to a maximum of 0.6% by
weight.
[0041] It can also be seen from Examples 1 to 4 that the respective
single-step annealing process for stability is, in this case,
carried out at a temperature ranging from 120 to 260.degree. C.,
and in particular ranging from 200 to 240.degree. C. The shortest
possible annealing process for stability is thus achieved, in which
it is ensured that for all cast component samples the required
short-term heat stability or long-term stability is obtained
without having to excessively or considerably reduce the yield
point Rp.sub.0.2.
[0042] A single-step annealing process for stability of this type
with temperatures within the disclosed temperature range, and in
particular <240.degree. C., may also be carried out during the
painting process for example, in particular during the paint baking
process of a motor vehicle. An annealing process for stability of
this type at such temperatures, i.e. for example a temperature of
<240.degree. C. for a duration of <180 mins, and in
particular <60 mins, also has the advantage that the cast
components are not distorted and can be heat-treated in a large
batch in a batch furnace.
[0043] A particular advantage when using the cast component, for
example within the field of vehicle manufacture, also lies in that
the cast component as cast, i.e. when it has minimum strength
(Rp.sub.0.2 approx. 100 MPa) and maximum ductility (A.sub.5 approx.
10 to 14%), can be mechanically joined, for example riveted. During
the subsequent heat treatment, which, for example, may be carried
out during the painting or paint baking process of the vehicle body
at, for example approximately 180.degree. C. for a period of
approximately 30 mins, the final mechanical values are set.
* * * * *