U.S. patent application number 14/991154 was filed with the patent office on 2016-07-14 for molten aluminum resistant alloys.
The applicant listed for this patent is Scoperta, Inc.. Invention is credited to Justin Lee Cheney, James Vecchio, Kenneth Vecchio.
Application Number | 20160201170 14/991154 |
Document ID | / |
Family ID | 56356504 |
Filed Date | 2016-07-14 |
United States Patent
Application |
20160201170 |
Kind Code |
A1 |
Vecchio; Kenneth ; et
al. |
July 14, 2016 |
MOLTEN ALUMINUM RESISTANT ALLOYS
Abstract
Embodiments of methods for protection a material from a reaction
from molten aluminum. In some embodiments, a coating can be applied
over a substrate which has significantly less of a reaction rate
with molten aluminum, thus preventing damage or chemical changes to
the substrate. The coating alloy can be formed from cast iron in
combination with niobium in some embodiments.
Inventors: |
Vecchio; Kenneth; (San
Diego, CA) ; Vecchio; James; (San Diego, CA) ;
Cheney; Justin Lee; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Scoperta, Inc. |
San Diego |
CA |
US |
|
|
Family ID: |
56356504 |
Appl. No.: |
14/991154 |
Filed: |
January 8, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62101873 |
Jan 9, 2015 |
|
|
|
Current U.S.
Class: |
164/47 ; 164/159;
420/10; 420/17; 420/422; 420/426 |
Current CPC
Class: |
B22C 1/00 20130101; B22C
9/061 20130101; B22C 9/101 20130101; B22C 3/00 20130101; C22C 37/08
20130101; B22D 21/007 20130101; C22C 37/10 20130101; C22C 27/02
20130101; C22C 37/00 20130101; C22C 16/00 20130101 |
International
Class: |
C22C 37/10 20060101
C22C037/10; C22C 37/00 20060101 C22C037/00; C22C 16/00 20060101
C22C016/00; B22D 21/00 20060101 B22D021/00; B22C 3/00 20060101
B22C003/00; B22C 1/00 20060101 B22C001/00; B22C 9/06 20060101
B22C009/06; B22C 9/10 20060101 B22C009/10; C22C 37/08 20060101
C22C037/08; C22C 27/02 20060101 C22C027/02 |
Claims
1. A method of protecting a component from molten aluminum
reaction, the method comprising: coating a component formed from a
base material with an alloy; wherein the alloy has a reaction level
to molten aluminum of less than 38 atomic %, the reaction level
being calculated by determining a minimum alloy content in a pseudo
binary alloy/aluminum phase diagram where the liquidus temperature
is at or above 1500K; and wherein the alloy has a minimum
concentration of highly resistant secondary phases of 5 mole %.
2. The method of claim 1, wherein the alloy is a Nb--Zr alloy with
30-60 wt. % Zr.
3. The method of claim 1, wherein the alloy has a reaction rate to
molten aluminum less than 50% than that of the base material.
4. The method of claim 1, wherein the alloy is a pseudo alloy of
grey cast iron and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 10 to 30 wt. %.
5. The method of claim 1, wherein the alloy is a pseudo alloy of
grey cast iron and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 0 to 10 wt. %.
6. The method of claim 1, wherein the alloy has a reaction rate
less than 10% than that of the base material.
7. The method of claim 1, wherein the alloy has a reaction rate
less than 5% than that of the base material.
8. An alloy resistant to molten aluminum, the alloy comprising: two
or more elements; a reaction level of less than 38 atom %, wherein
the reaction level is calculated by determining a minimum alloy
content in a pseudo binary alloy/aluminum phase diagram where the
liquidus temperature is at or above 1500K; and a minimum
concentration of highly resistant secondary phases of 5 mole %.
9. The alloy of claim 8, wherein the reaction level is 10 atom % or
less.
10. The alloy of claim 8, wherein the reaction level is 5 atom % or
less.
11. The alloy of claim 8, wherein the alloy is a Nb--Zr alloy with
30-60 wt. % Zr.
12. The alloy of claim 8, wherein the alloy is a pseudo alloy of
grey cast iron and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 10 to 30 wt. %.
13. The alloy of claim 8, wherein the alloy is a pseudo alloy of
grey cast iron and niobium according to the formula: (grey cast
.sub.iron).sub.100-xNb.sub.x with x ranging from 0 to 10 wt. %.
14. The alloy of claim 8, wherein the alloy has a minimum
concentration of highly resistant secondary phases of 10 mole
%.
15. The alloy of claim 8, wherein the alloy has a minimum
concentration of highly resistant secondary phases of 20 mole
%.
16. The alloy of claim 8, wherein the alloy comprises Fe and the
following in weight percent: Nb: about 10; Si: 0 to about 2; Mn: 0
to about 2; and C: 0 to about 2.5.
17. The alloy of claim 8, wherein the alloy comprises Fe and one of
the following in weight percent: Nb: about 10, Si: about 1.6, Mn:
about 0.5, C: about 2.5; Nb: about 10, Si: about 1.6, Mn: about
0.5, C: about 2.0; Nb: about 10, Si: about 1.6, Mn: about 0.5, C:
about 1.5; or Nb: about 10, Si: about 1.6, Mn: about 0.5, C: about
1.0.
18. The alloy of claim 8, wherein the alloy is a coating on a base
substrate.
19. The alloy of claim 8, wherein the alloy is a casting component
for casting molten aluminum.
20. An article of manufacture for use in an aluminum casting
process, the article comprising: an alloy forming at least a
portion of the article; wherein the alloy has a reaction level to
molten aluminum of less than 38 atomic %, the reaction level being
calculated by determining a minimum alloy content in a pseudo
binary alloy/aluminum phase diagram where the liquidus temperature
is at or above 1500K; and wherein the alloy has a minimum
concentration of highly resistant secondary phases of 5 mole %.
21. The article of manufacture of claim 20, wherein the alloy is a
grey cast iron.
22. The article of manufacture of claim 20, wherein the alloy has a
reaction rate in molten aluminum of less than or equal to 1/2 the
rate of H13 steel.
23. The article of manufacture of claim 20, wherein the alloy is
pseudo alloy of grey cast iron and niobium according to the
formula: (grey cast iron).sub.100-xNb.sub.x with x ranging from 0
to 10 wt. %.
24. The article of manufacture of claim 20, wherein the alloy has a
reaction rate less than 10% than that of the H13 steel.
25. The article of manufacture of claim 20, wherein the alloy has a
reaction rate less than 5% than that of the H13 steel.
26. A casting component for casting aluminum, wherein the casting
component is either clad with or is comprised of a metal alloy
composition, the metal alloy composition having a reaction level of
about 38 atom % or less, wherein the reaction level is defined as
the minimum alloy content of the metal alloy composition in the
phase diagram between aluminum and the metal alloy composition
where the liquidus curve is at or above 1500 K.
27. The casting component of claim 26, wherein the alloy has a
reaction rate in molten aluminum of less than or equal to 1/2 the
rate of H13 steel.
28. The casting component of claim 26, wherein a % loss of an alloy
rod, based on area loss and diameter loss, formed the metal alloy
composition is less than 5% after undergoing a molten aluminum flow
rate of 0.2 meters/second.
29. A method of casting aluminum, comprising: providing molten
aluminum into contact with a surface of a casting component,
wherein the casting component is either clad with or is comprised
of a metal alloy composition, the metal alloy composition having a
reaction level of about 38 atom % or less, wherein the reaction
level is defined as the minimum alloy content of the metal alloy
composition in the phase diagram between aluminum and the metal
alloy composition where the liquidus curve is at or above 1500 K;
and casting the molten aluminum.
Description
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS
[0001] Any and all applications for which a foreign or domestic
priority claim is identified in the Application Data Sheet as filed
with the present application are hereby incorporated by reference
under 37 CFR 1.57.
BACKGROUND
[0002] 1. Field
[0003] This disclosure generally relates to materials and coatings
which can be resistant to flowing molten aluminum, and methods for
producing the same.
[0004] 2. Description of the Related Art
[0005] Casting components can degrade due to their reaction with
molten aluminum during the manufacturing of aluminum parts within
the casting component. The reaction rate between the casting
component and the molten aluminum thus can govern the lifetime of
the components' utility. The reaction rate can be increased and
lifetime decreased when the component is subject to contact with
flowing aluminum due to the component experiencing more of a
reaction with the molten aluminum.
[0006] One conventional material used to create components by the
aluminum casting industry due to its relatively high resistance to
molten aluminum is H13 steel. H13 steel has the composition of:
Fe-bal, C: 0.32-0.40, Cr: 5.13-5.25, Mo: 1.33-1.4, Si: 1, V: 1, and
the steel is air or oil quenched from 1000.degree. C.-1025.degree.
C.
SUMMARY
[0007] Disclosed herein in some embodiments are methods of
protecting a component from molten aluminum reaction. The method
may comprise coating a component formed from a base material with
an alloy, wherein the alloy has a reaction rate to aluminum less
than 50% than that of the base material.
[0008] In some embodiments, the alloy can be a Nb--Zr alloy with
30-60 wt. % Zr. In some embodiments, the alloy can be a grey cast
iron. In some embodiments, the alloy can be a pseudo alloy of grey
cast iron and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 10 to 30 wt. %. In some
embodiments, the alloy can be a pseudo alloy of grey cast iron and
niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 0 to 10 wt. %.
[0009] In some embodiments, the alloy can have a reaction rate less
than 10% than that of the base material. In some embodiments, the
alloy can have a reaction rate less than 5% than that of the base
material.
[0010] Also disclosed herein are embodiments of an alloy resistant
to molten aluminum, the alloy comprising two or more elements,
wherein the alloy has a reaction level of less than 38 atom %,
wherein the reaction level is calculated by determining a minimum
alloy content in a pseudo binary alloy/aluminum phase diagram where
the liquidus temperature is at or above 1500K. In some embodiments,
the reaction level can be 10 atom % or less. In some embodiments,
the reaction level can be 5 atom % or less.
[0011] In some embodiments, the alloy can be a Nb--Zr alloy with
30-60 wt. % Zr. In some embodiments, the alloy can be a grey cast
iron. In some embodiments, the alloy can be a pseudo alloy of grey
cast iron and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 10 to 30 wt. %. In some
embodiments, the alloy can be a pseudo alloy of grey cast iron and
niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 0 to 10 wt. %.
[0012] Also disclosed herein are embodiments of an alloy resistant
to molten aluminum, the alloy comprising two or more elements,
wherein the alloy has a reaction level of less than 40 atom %,
wherein the reaction level is calculated by determining a minimum
alloy content in a pseudo binary alloy/aluminum phase diagram where
the liquidus temperature is at or above 1500K. In some embodiments,
the reaction level can be 10 atom % or less. In some embodiments,
the reaction level can be 5 atom % or less.
[0013] Also disclosed herein are embodiments of an article of
manufacture for use in an aluminum casting process, the article
comprising at least a portion of an alloy, wherein the alloy has a
reaction rate in molten aluminum of less than or equal to 1/2 the
rate of H13 steel.
[0014] In some embodiments, the alloy can be a grey cast iron. In
some embodiments, the alloy can be pseudo alloy of grey cast iron
and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 0 to 10 wt. %.
[0015] In some embodiments, the alloy can have a reaction rate less
than 10% than that of the base material. In some embodiments, the
alloy can have a reaction rate less than 5% than that of the base
material.
[0016] Also disclosed herein are embodiments of a casting component
for casting aluminum, wherein the casting component is either clad
with or is comprised of a metal alloy composition, the metal alloy
composition having a reaction level of about 38 atom % or less,
wherein the reaction level is defined as the minimum alloy content
of the metal alloy composition in the phase diagram between
aluminum and the metal alloy composition where the liquidus curve
is at or above 1500 K.
[0017] In some embodiments, the alloy can have a reaction rate in
molten aluminum of less than or equal to 1/2 the rate of H13 steel.
In some embodiments, a % loss of an alloy rod, based on area loss
and diameter loss, formed the metal alloy composition can be less
than 5% after undergoing a molten aluminum flow rate of 0.2
meters/second.
[0018] Also disclosed herein are embodiments of a casting component
for casting aluminum, wherein the casting component is either clad
with or is comprised of a metal alloy composition, the metal alloy
composition having a reaction level of about 40 atom % or less,
wherein the reaction level is defined as the minimum alloy content
of the metal alloy composition in the phase diagram between
aluminum and the metal alloy composition where the liquidus curve
is at or above 1500 K.
[0019] Also disclosed herein are embodiments of a method of casting
aluminum, comprising providing molten aluminum into contact with a
surface of a casting component, wherein the casting component is
either clad with or is comprised of a metal alloy composition, the
metal alloy composition having a reaction level of about 38 atom %
or less, wherein the reaction level is defined as the minimum alloy
content of the metal alloy composition in the phase diagram between
aluminum and the metal alloy composition where the liquidus curve
is at or above 1500 K; and casting the molten aluminum.
[0020] Also disclosed herein are embodiments of a method of casting
aluminum, comprising providing molten aluminum into contact with a
surface of a casting component, wherein the casting component is
either clad with or is comprised of a metal alloy composition, the
metal alloy composition having a reaction level of about 40 atom %
or less, wherein the reaction level is defined as the minimum alloy
content of the metal alloy composition in the phase diagram between
aluminum and the metal alloy composition where the liquidus curve
is at or above 1500 K; and casting the molten aluminum.
[0021] Also disclosed herein are embodiments of a method of
protecting a component from molten aluminum reaction, the method
comprising coating a component formed from a base material with an
alloy, wherein the alloy has a reaction level to molten aluminum of
less than 38 atomic %, the reaction level being calculated by
determining a minimum alloy content in a pseudo binary
alloy/aluminum phase diagram where the liquidus temperature is at
or above 1500K, and wherein the alloy has a minimum concentration
of highly resistant secondary phases of 5 mole %.
[0022] Also disclosed herein are embodiments of a method of
protecting a component from molten aluminum reaction, the method
comprising coating a component formed from a base material with an
alloy, wherein the alloy has a reaction level to molten aluminum of
less than 40 atomic %, the reaction level being calculated by
determining a minimum alloy content in a pseudo binary
alloy/aluminum phase diagram where the liquidus temperature is at
or above 1500K, and wherein the alloy has a minimum concentration
of highly resistant secondary phases of 5 mole %.
[0023] In some embodiments, the alloy can be a Nb--Zr alloy with
30-60 wt. % Zr. In some embodiments, the alloy can have a reaction
rate to molten aluminum less than 50% than that of the base
material. In some embodiments, the alloy can be a pseudo alloy of
grey cast iron and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 10 to 30 wt. %. In some
embodiments, the alloy can be a pseudo alloy of grey cast iron and
niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 0 to 10 wt. %. In some
embodiments, the alloy can have a reaction rate less than 10% than
that of the base material. In some embodiments, the alloy can have
a reaction rate less than 5% than that of the base material.
[0024] Also disclosed herein are embodiments of an alloy resistant
to molten aluminum, the alloy comprising two or more elements, a
reaction level of less than 38 atom %, wherein the reaction level
is calculated by determining a minimum alloy content in a pseudo
binary alloy/aluminum phase diagram where the liquidus temperature
is at or above 1500K, and a minimum concentration of highly
resistant secondary phases of 5 mole %.
[0025] In some embodiments, the reaction level can be 10 atom % or
less. In some embodiments, the reaction level can be 5 atom % or
less. In some embodiments, the alloy can be a Nb--Zr alloy with
30-60 wt. % Zr.
[0026] Also disclosed herein are embodiments of an alloy resistant
to molten aluminum, the alloy comprising two or more elements, a
reaction level of less than 40 atom %, wherein the reaction level
is calculated by determining a minimum alloy content in a pseudo
binary alloy/aluminum phase diagram where the liquidus temperature
is at or above 1500K, and a minimum concentration of highly
resistant secondary phases of 5 mole %.
[0027] In some embodiments, the alloy can be a pseudo alloy of grey
cast iron and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 10 to 30 wt. %. In some
embodiments, the alloy can be a pseudo alloy of grey cast iron and
niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 0 to 10 wt. %. In some
embodiments, the alloy can have a minimum concentration of highly
resistant secondary phases of 10 mole %. In some embodiments, the
alloy can have a minimum concentration of highly resistant
secondary phases of 20 mole %.
[0028] In some embodiments, the alloy can comprise Fe and the
following in weight percent: Nb: about 10, Si: 0 to about 2, Mn: 0
to about 2, and C: 0 to about 2.5. In some embodiments, the alloy
can comprise Fe and one of the following in weight percent: Nb:
about 10, Si: about 1.6, Mn: about 0.5, C: about 2.5; Nb: about 10,
Si: about 1.6, Mn: about 0.5, C: about 2.0; Nb: about 10, Si: about
1.6, Mn: about 0.5, C: about 1.5; or Nb: about 10, Si: about 1.6,
Mn: about 0.5, C: about 1.0.
[0029] In some embodiments, the alloy can be a coating on a base
substrate. In some embodiments, the alloy can be a casting
component for casting molten aluminum.
[0030] Also disclosed herein are embodiments of an article of
manufacture for use in an aluminum casting process, the article
comprising an alloy forming at least a portion of the article,
wherein the alloy has a reaction level to molten aluminum of less
than 38 atomic %, the reaction level being calculated by
determining a minimum alloy content in a pseudo binary
alloy/aluminum phase diagram where the liquidus temperature is at
or above 1500K, and wherein the alloy has a minimum concentration
of highly resistant secondary phases of 5 mole %.
[0031] In some embodiments, the alloy can be a grey cast iron. In
some embodiments, the alloy can have a reaction rate in molten
aluminum of less than or equal to 1/2 the rate of H13 steel. In
some embodiments, the alloy can be pseudo alloy of grey cast iron
and niobium according to the formula: (grey cast
iron).sub.100-xNb.sub.x with x ranging from 0 to 10 wt. %. In some
embodiments, the alloy can have a reaction rate less than 10% than
that of the H13 steel. In some embodiments, the alloy can have a
reaction rate less than 5% than that of the H13 steel.
[0032] Also disclosed herein are embodiments of an article of
manufacture for use in an aluminum casting process, the article
comprising an alloy forming at least a portion of the article,
wherein the alloy has a reaction level to molten aluminum of less
than 40 atomic %, the reaction level being calculated by
determining a minimum alloy content in a pseudo binary
alloy/aluminum phase diagram where the liquidus temperature is at
or above 1500K, and wherein the alloy has a minimum concentration
of highly resistant secondary phases of 5 mole %.
[0033] Also disclosed herein are embodiments of a method of
protecting a component from molten aluminum reaction, the method
comprising coating a component formed from a base material with an
alloy, wherein the alloy has a reaction level to molten aluminum of
less than 38 atomic %, the reaction level being calculated by
determining a minimum alloy content in a pseudo binary
alloy/aluminum phase diagram where the liquidus temperature is at
or above 1500K, and wherein the alloy has a minimum concentration
of highly resistant secondary phases of 5 mole %.
[0034] Also disclosed herein are embodiments of a method of
protecting a component from molten aluminum reaction, the method
comprising coating a component formed from a base material with an
alloy, wherein the alloy has a reaction level to molten aluminum of
less than 40 atomic %, the reaction level being calculated by
determining a minimum alloy content in a pseudo binary
alloy/aluminum phase diagram where the liquidus temperature is at
or above 1500K, and wherein the alloy has a minimum concentration
of highly resistant secondary phases of 5 mole %.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 illustrates a phase diagram of an alloy showing
calculation of reaction level according to certain embodiments of
the disclosure.
[0036] FIG. 2 illustrates an SEM micrograph showing reaction width
measurement according to certain embodiments of the disclosure.
[0037] FIG. 3 illustrates a sample coupon after an aluminum bath
exposure showing area loss measurements according to certain
embodiments of the disclosure.
DETAILED DESCRIPTION
[0038] Disclosed herein are embodiments of several methods for
improving the lifetime of casting components that can come into
contact (either intentionally or unintentionally) with molten
aluminum, as well as alloys and articles resistant to deleterious
effects of molten aluminum. Several non-limiting examples of
casting components that can have the resistance to molten aluminum
include casting nozzles and casting molds, though other casting
components could be used as well. In some embodiments, the casting
components can be coated with an aluminum-resistant alloy, and thus
have a different material substrate underneath the coating, or can
be manufactured partially or completely from an aluminum-resistant
alloy.
[0039] In some embodiments of the present disclosure, a method of
protection is described which can involve the cladding, or coating,
of conventional components with a material which can have enhanced
resistance to molten aluminum. Cladding can involve the deposition
of a layer of a high resistance material, and can be deposited
using a variety of techniques including, but not limited to: TIG
welding, MIG welding, thermal spray, PTA welding, laser cladding,
etc. A successful cladding can protect the component from contact
with the molten aluminum, and thus the lifetime of the component
can be governed by the reaction rate of the cladding material and
not the underlying component. In some embodiments, the cladding can
increase the lifetime of the component by 10% (or about 10%) or
more as compared to the underlying component. In some embodiments,
the cladding can increase the lifetime of the component by 200% (or
about 200%) or more as compared to the underlying component. In
some embodiments, the cladding can increase the lifetime of the
component by 400% (or about 400%) or more as compared to the
underlying component.
[0040] In some embodiments, a method for increasing lifetime is
described by which the component itself can be made from an alloy
which is highly resistant to molten aluminum. To describe this
embodiment, the resistant alloy that is made to use the component
itself is compared against a conventional material used to create
components by the aluminum casting industry, H13 steel. H13 steel
is Fe-bal, C: 0.32-0.40, Cr: 5.13-5.25, Mo: 1.33-1.4, Si: 1, V: 1
which is air or oil quenched from 1000.degree. C.-1025.degree.
C.
[0041] In some embodiments, the use of a resistant alloy to
fabricate the component can increase the lifetime of component by
10% (or about 10%) or more compared to H13 steel. In some
embodiments, the use of a resistant alloy to fabricate the
component can increase the lifetime by 200% (or about 200%) or more
compared to an H13 steel component. In some embodiments, the use of
a resistant alloy to fabricate the component can increase the
lifetime by 400% (or about 400%) or more compared to a H13 steel
component.
[0042] As disclosed herein, the term alloy can refer to the
chemical composition of powder used to form a desired component,
the powder itself (such as feedstock), the composition of a metal
component formed, for example, by the heating and/or deposition of
the powder, and the metal component itself.
Metal Alloy Composition
[0043] In some embodiments, this disclosure can be fully described
by the metal alloy compositions. In some embodiments, the alloy
compositions can be used to form the cladding layer or used to
fabricate the component.
[0044] Table 1 lists the alloy chemistries evaluated according to
the base element and the alloying element composition (in weight
percent). In some embodiments, grey cast iron is listed as the base
element. The particular alloys were chosen based on their reaction
level with Al determined from a binary phase diagram between the
alloying element and Al. In these embodiments, the composition for
gray cast iron is the base alloy whereby alloying additions are
added. For example, in the case of alloy 25, grey cast iron makes
up 90% (or about 90%) of the alloy chemistry and pure Nb makes up
the remaining 10% (or about 10%), also commonly written as (grey
cast iron).sub.90Nb.sub.10. For the purposes of defining alloys in
this disclosure grey cast iron is any iron-based material with 2.5
to 4 wt. % carbon (or about 2.5 to about 4 wt. % carbon). In some
embodiments, the grey cast iron can contain a graphite phase.
TABLE-US-00001 TABLE 1 Experimental Alloys Evaluated in this Study
Alloy Base Element Alloying Elements 1 Zr 40% Ta 2 Zr 30% Ta, 10% W
3 Zr 20% Ta, 20% W 4 Zr 10% Ta, 30% W 5 Zr 40% W 6 Ti 40% Ta 7 Ti
30% Ta, 10% W 8 Ti 20% Ta, 20% W 9 Ti 10% Ta, 30% W 10 Ti 40% W 11
Nb 30% Fe 12 Nb 40% Fe 13 Nb 50% Fe 14 Fe 40% Nb 15 Nb 30% Ti 16 Nb
40% Ti 17 Nb 50% Ti 18 Ti 40% Nb 19 Nb 30% Zr 20 Nb 40% Zr 21 Nb
50% Zr 22 Zr 40% Nb 23 Zr 30% Nb 24 Grey Cast Iron 0% (GCI) 25 GCI
10% Nb 26 GCI 20% Nb 27 GCI 30% Nb 28 GCI 10% Zr 29 GCI 20% Zr 30
GCI 30% Zr
[0045] Other base alloys can be used as well as the above, such as
niobium, vanadium, zirconium, titanium, tantalum, tungsten, and
molybdenum. In some embodiments, a combination of Nb--V--Zr--Ti may
provide advantageous properties. In some embodiments, certain
metals can be avoided such as copper, nickel, palladium, hafnium,
platinum, iron, chromium, cobalt, and manganese.
[0046] In some embodiments, the alloy can be considered a pseudo
alloy with a pseudo binary phase diagram. A pseudo binary phase
diagram is a common phrase used by metallurgists to describe a
phase diagram where one of the sides is not a pure element. In some
embodiments such as those shown in the above Table 1, the alloy
might be 60Zr-40Nb and a pseudo binary phase diagram can be
evaluated where one end of the phase diagram is pure 60Zr-40Nb and
the other end is pure Al. This is not a true binary phase diagram
because any point on the diagram is really a three element
alloy.
[0047] In some embodiments, the alloy can be further modified from
Alloy 25 presented in Table 1. Specifically, the carbon level can
be reduced to reduce or prevent the potential of the weld overlay
to crack. In such embodiments, the alloy can comprise the following
elemental ranges in weight percent (balance iron): [0048] Nb: 0 to
10 (or about 0 to about 10) [0049] Si: 0 to 2 (or about 0 to about
2) [0050] Mn: 0 to 2 (or about 0 to about 2) [0051] C: 0 to 2.5 (or
about 0 to about 2.5)
[0052] In some embodiments, the alloy can comprise the following in
weight percent: [0053] Fe: Bal, Nb: 10, Si: 1.6, Mn: 0.5, C: 2.15
(or Fe: Bal, Nb: about 10, Si: about 1.6, Mn: about 0.5, C: about
2.5) [0054] Fe: Bal, Nb: 10, Si: 1.6, Mn: 0.5, C: 2.0 (or Fe: Bal,
Nb: about 10, Si: about 1.6, Mn: about 0.5, C: about 2.0) [0055]
Fe: Bal, Nb: 10, Si: 1.6, Mn: 0.5, C: 1.5 (or Fe: Bal, Nb: about
10, Si: about 1.6, Mn: about 0.5, C: about 1.5) [0056] Fe: Bal, Nb:
10, Si: 1.6, Mn: 0.5, C: 1.0 (or Fe: Bal, Nb: about 10, Si: about
1.6, Mn: about 0.5, C: about 1.0)
[0057] In some embodiments, for the elements listed above that are
listed from 0-X, the alloy may contain a non-zero amount of that
element.
[0058] The disclosed alloys can incorporate the above elemental
constituents to a total of 100 wt. %. In some embodiments, the
alloy may include, may be limited to, or may consist essentially of
the above named elements. In some embodiments, the alloy may
include 2% or less of impurities. Impurities may be understood as
elements or compositions that may be included in the alloys due to
inclusion in the feedstock components, through introduction in the
manufacturing process.
[0059] Further, the Fe content identified in all of the
compositions described in the above paragraphs may be the balance
of the composition as indicated above, or alternatively, the
balance (or remainder) of the composition may comprise Fe and other
elements. In some embodiments, the balance may consist essentially
of Fe and may include incidental impurities.
Thermodynamic Criteria
[0060] In some embodiments, this disclosure can be fully described
by the thermodynamic criteria, which can be used to predict the
desired performance of the alloy. Specifically, certain criteria
can be used to define the thermodynamic behavior of the alloys. The
criteria can be used to define the reaction rate of the alloy with
molten aluminum. The criteria are advantageous in order to use
computational metallurgy to design the best performing alloys from
the billions of potential choices.
[0061] The first criterion is defined as the reaction level [101]
shown in FIG. 1. The reaction level is calculated using
thermodynamic phase diagrams, such as the Fe--Al phase diagram
shown in FIG. 1. The Fe--Al phase diagram shows an example of the
methodology for determining the reaction level of an individual
element with Al. The reaction level is calculated by evaluating the
minimum alloy content of the alloy element that is reacting with Al
where the liquidus curve is at or above 1500K, which is a relevant
temperature at which an aluminum casting component might operate
(e.g., this is the conventional temperature used for casting
aluminum parts). As shown in FIG. 1, the reaction level of pure
iron according to this criterion would be between 38 atom % (or
about 38 atom %) and 40 atom % (or about 40 atom %) as shown at the
intersection of the 1500K isotherm with the liquidus line.
Decreasing reaction levels can correspond to decreasing reaction
rates with molten aluminum and thereby increasing component
lifetime. As the reaction level goes down, the reaction rate of the
alloy with molten aluminum decreases and component lifetime
increases. Therefore, an alloy with a low reaction level can be the
most resistant to molten aluminum attack. The reaction level of H13
would be similar to the reaction level of Fe.
[0062] If an iron component is in a molten Al environment, the
reaction level tells that at 1500K the liquid could have up to 38%
dissolved iron in it. A lower reaction level, such as 10%, can
indicate that the liquid can contain up to 10% dissolved iron.
Therefore, a lower reaction level signifies a decreasing ability of
the liquid to dissolve the solid component and thereby an increase
in the lifetime of the solid.
[0063] In some embodiments, the alloy can have a reaction level of
less than 40 atom % (or less than about 40 atom %). In some
embodiments, the alloy can have a reaction level of less than 39
atom % (or less than about 39 atom %). In some embodiments, the
alloy can have a reaction level of less than 38 atom % (or less
than about 38 atom %). In some embodiments, the alloy can have a
reaction level of less than 10 atom % (or less than about 10 atom
%). In some embodiments, the alloy can have a reaction level of
less than 5 atom % (or less than about 5 atom %).
[0064] In some embodiments, the alloy can have a reaction level of
40 atom % (or about 40 atom %) or less. In some embodiments, the
alloy can have a reaction level of 39 atom % (or about 39 atom %)
or less. In some embodiments, the alloy can have a reaction level
of 38 atom % (or about 38 atom %) or less. In some embodiments, the
alloy can have a reaction level of 10 atom % (or about 10 atom %)
or less. In some embodiments, the alloy can have a reaction level
of 5 atom % (or about 5 atom %) or less.
[0065] The second criterion is the reaction slope at 1500K and is
calculated by evaluating the slope of the liquidus curve at 1500K
in the alloy/pure aluminum phase diagram. A steeper slope predicts
a lower reaction rate and a shallower slope predicts a higher
reaction rate. Thus, reaction improvements can be made by
increasing the liquidus curve slope at a particular temperature,
such as the 1500K discussed in the examples herein.
[0066] Accordingly, the general principles discussed herein are to
shift the liquidus and temperature isotherm point (at whatever
desirable temperature that maybe) towards the Al side of the phase
diagram (e.g., making the alloy have more limited solubility of the
specific alloy metal with Al) while also increasing the slope of
the liquidus curve at that particular temperature (e.g., requiring
higher and higher temperatures to achieve more metal solubility in
molten Al). This can give alloys which are more resistant to the
molten aluminum, thus having less reaction, and may be more easily
used in liquid aluminum applications.
[0067] It will be understood that 1500K is a representative number
that is based on the conventional melting temperature of aluminum.
This temperature value can be adjusted as necessary for a
particular configuration, for example different aluminum alloys may
achieve solidification at higher or lower melting temperatures. The
same application as above can be thus applied to those temperatures
as well. Further, the phase diagram disclosed with respect to Fe
and Al is just one embodiment, and different phase diagrams having
different properties can be used as well.
[0068] The above two criteria are methods by which the behavior of
a homogenous alloy or alloy matrix can be predicted. However, it
has been determined in this study through extensive experimentation
that the alloy's resistance to molten aluminum can be further
enhanced through the growth of secondary phases, which are highly
resistant to molten aluminum. Examples of such phases include
graphite and/or carbides. Carbides provide the additional advantage
of providing some wear resistance to the alloy. In some
embodiments, a highly resistant secondary phase can have a measured
reaction rate below a certain threshold. In some embodiments, the
highly resistant secondary phases can have a measured reaction rate
of below 0.5 .mu.m/hr (or below about 0.5 .mu.m/hr).
[0069] In some embodiments, the alloy can have a minimum
concentration of highly resistant secondary phases. Highly
resistant secondary phases are calculated thermodynamically for a
given alloy at room temperature and are given in mole fraction. In
some embodiments, the alloy can have a minimum of 5 mole % (or
about 5 mole %) of highly resistant secondary phases. In some
embodiments, the alloy can have a minimum of 10 mole % (or about 10
mole %) of highly resistant secondary phases. In some embodiments,
the alloy can have a minimum of 20 mole % (or about 20 mole %) of
highly resistant secondary phases.
Performance Criteria
[0070] In some embodiments, the alloy can be fully described by a
set of performance criteria used to measure the resistance to
molten aluminum attack. Through extensive experimentation, two test
methods were developed in order to characterize molten aluminum
resistivity.
[0071] The first method involved submerging the alloy in a molten
aluminum bath at 750.degree. C. temperature for 48 hours. In order
to draw accurate comparison, H13 steel, a common alloy used in the
aluminum casting industry, was tested in this way. The reaction
width is used as a metric to characterize the reaction rate of the
alloy. As shown in FIG. 2, the reaction width [201] is defined as
the distance by which the alloy shows reaction with the molten
aluminum. The micrograph shows three distinct regions, 1) unreacted
H13 steel [202], 2) a reaction region which of which is used to
calculate the reaction width [203], and 3) aluminum rich region
[204]. One skilled in the art can easily distinguish all three
regions using energy dispersive spectroscopy.
[0072] The reaction rate of the material can then be calculated
based on the reaction width measurement and the testing time.
Reaction rate measurements are shown in Table 2 for a selection of
experimental alloys. As shown, the majority of experimental alloys
tested do not show an improvement in reaction rate, thus
demonstrating the difficulty in designing such an alloy. Also shown
is the improvement factor over H13 steel, which is a useful metric
to define the molten aluminum resistance of the alloy.
[0073] In some embodiments, the alloy can show a molten aluminum
resistance which is 2 times or better (or about 2 times or more
better) than a base material, such as H13 steel. In some
embodiments, the alloy can show a molten aluminum resistance which
is 10 times or better (or about 10 times or more better) than H13
steel. In some embodiments, the alloy can show a molten aluminum
resistance which is 40 times or better (or about 40 times or more
better) than H13 steel.
[0074] Accordingly, in some embodiments where the alloy is coated
on a base material, the alloy can have a reaction rate to molten
aluminum that is less than 50% (or less than about 50%) than the
reaction rate of the base material it is coated on, such as H13
steel. In some embodiments, the alloy can have a reaction rate that
is less than 10% (or less than about 10%) than the reaction rate of
the base material it is coated on. In some embodiments, the alloy
can have a reaction rate that is less than 5% (or less than about
5%) than the reaction rate of the base material it is coated
on.
TABLE-US-00002 TABLE 2 Reaction Rates of Experimental Alloys #
Sample um/hr Improvement Factor 1 60Zr-40Nb 0.22 40.9 2 50Zr-50Nb
0.25 36.0 3 40Zr-60Nb 0.27 33.3 4 Grey Cast Fe 0.5 18.0 5 30Zr-70Nb
2.2 4.1 6 60Fe-40Nb 4.2 2.1 7 H13 #3 9 1.0 8 H13 #2 9.3 1.0 9
50Fe-50Nb 11.1 0.8 10 H13 #1 12.2 0.7 11 40Ti-60Nb 12.5 0.7 12
30Ti-70Nb 13.7 0.7 13 40Fe-60Nb 14.2 0.6 14 60Ti-40Nb 32.8 0.3 15
30Fe-70Nb 35.1 0.3 16 50Ti-50Nb 48.9 0.2
[0075] A second method was devised in order to characterize the
resistance of the alloy in the presence of flowing molten aluminum.
In this method, a 0.25'' diameter alloy rod was manufactured and
spun in a bath of molten aluminum at a 470 rotational speed. These
testing conditions resulted in a flow rate of 0.2 meters/second on
the surface of the alloy coupon. The performance of the
experimental alloys in this test is shown in Table 3. The diameter
and area loss of the specimen is measured according to FIG. 3. The
original diameter of the sample [302] and the diameter of the
un-reacted area of the sample after exposure [301] are used to
calculate the % loss of each experimental alloy composition. It can
be advantageous to have a % loss less than that of H13.
TABLE-US-00003 TABLE 3 Reaction Rates of alloys in 2.sup.nd method.
Sample Area Loss Dia. Loss % Loss H13 #2 2.61 0.14 5.94 70Zr-30Nb
0.65 0.048 1.47 60Zr-40Nb 0.66 0.06 1.49 50Zr-50Nb 0.11 0.029 0.25
40Zr-60Nb 4.22 0.24 8.64 GCI-10Zr 8.67 0.58 19.5 GCI-20Zr 4.11 0.34
9.4 GCI-30Zr 21.49 1.57 45.79 GCI-10Nb 1.51 0.11 3.36 GCI-20Nb 7.44
0.86 16.9 GCI-30Nb 4.1 0.057 9.4
[0076] From the foregoing description, it will be appreciated that
an inventive alloys resistant to molten aluminum are disclosed.
While several components, techniques and aspects have been
described with a certain degree of particularity, it is manifest
that many changes can be made in the specific designs,
constructions and methodology herein above described without
departing from the spirit and scope of this disclosure.
[0077] Certain features that are described in this disclosure in
the context of separate implementations can also be implemented in
combination in a single implementation. Conversely, various
features that are described in the context of a single
implementation can also be implemented in multiple implementations
separately or in any suitable subcombination. Moreover, although
features may be described above as acting in certain combinations,
one or more features from a claimed combination can, in some cases,
be excised from the combination, and the combination may be claimed
as any subcombination or variation of any subcombination.
[0078] Moreover, while methods may be depicted in the drawings or
described in the specification in a particular order, such methods
need not be performed in the particular order shown or in
sequential order, and that all methods need not be performed, to
achieve desirable results. Other methods that are not depicted or
described can be incorporated in the example methods and processes.
For example, one or more additional methods can be performed
before, after, simultaneously, or between any of the described
methods. Further, the methods may be rearranged or reordered in
other implementations. Also, the separation of various system
components in the implementations described above should not be
understood as requiring such separation in all implementations, and
it should be understood that the described components and systems
can generally be integrated together in a single product or
packaged into multiple products. Additionally, other
implementations are within the scope of this disclosure.
[0079] Conditional language, such as "can," "could," "might," or
"may," unless specifically stated otherwise, or otherwise
understood within the context as used, is generally intended to
convey that certain embodiments include or do not include, certain
features, elements, and/or steps. Thus, such conditional language
is not generally intended to imply that features, elements, and/or
steps are in any way required for one or more embodiments.
[0080] Conjunctive language such as the phrase "at least one of X,
Y, and Z," unless specifically stated otherwise, is otherwise
understood with the context as used in general to convey that an
item, term, etc. may be either X, Y, or Z. Thus, such conjunctive
language is not generally intended to imply that certain
embodiments require the presence of at least one of X, at least one
of Y, and at least one of Z.
[0081] Language of degree used herein, such as the terms
"approximately," "about," "generally," and "substantially" as used
herein represent a value, amount, or characteristic close to the
stated value, amount, or characteristic that still performs a
desired function or achieves a desired result. For example, the
terms "approximately", "about", "generally," and "substantially"
may refer to an amount that is within less than or equal to 10% of,
within less than or equal to 5% of, within less than or equal to 1%
of, within less than or equal to 0.1% of, and within less than or
equal to 0.01% of the stated amount. If the stated amount is 0
(e.g., none, having no), the above recited ranges can be specific
ranges, and not within a particular % of the value. For example,
within less than or equal to 10 wt./vol. % of, within less than or
equal to 5 wt./vol. % of, within less than or equal to 1 wt./vol. %
of, within less than or equal to 0.1 wt./vol. % of, and within less
than or equal to 0.01 wt./vol. % of the stated amount.
[0082] Some embodiments have been described in connection with the
accompanying drawings. The figures are drawn to scale, but such
scale should not be limiting, since dimensions and proportions
other than what are shown are contemplated and are within the scope
of the disclosed inventions. Distances, angles, etc. are merely
illustrative and do not necessarily bear an exact relationship to
actual dimensions and layout of the devices illustrated. Components
can be added, removed, and/or rearranged. Further, the disclosure
herein of any particular feature, aspect, method, property,
characteristic, quality, attribute, element, or the like in
connection with various embodiments can be used in all other
embodiments set forth herein. Additionally, it will be recognized
that any methods described herein may be practiced using any device
suitable for performing the recited steps.
[0083] While a number of embodiments and variations thereof have
been described in detail, other modifications and methods of using
the same will be apparent to those of skill in the art.
Accordingly, it should be understood that various applications,
modifications, materials, and substitutions can be made of
equivalents without departing from the unique and inventive
disclosure herein or the scope of the claims.
* * * * *