U.S. patent application number 14/695437 was filed with the patent office on 2016-10-27 for die-casting system with enhanced adherence shot sleeve pour liner.
The applicant listed for this patent is UNITED TECHNOLOGIES CORPORATION. Invention is credited to MARIO P. BOCHIECHIO, ZHENG CHUAN CHEN, CHEE YAO HUI, LIM YUAN KWANG, CHARLENE KWAN YEE LING, AWADH B. PANDEY, DILIP M. SHAH.
Application Number | 20160311015 14/695437 |
Document ID | / |
Family ID | 57146635 |
Filed Date | 2016-10-27 |
United States Patent
Application |
20160311015 |
Kind Code |
A1 |
KWANG; LIM YUAN ; et
al. |
October 27, 2016 |
DIE-CASTING SYSTEM WITH ENHANCED ADHERENCE SHOT SLEEVE POUR
LINER
Abstract
A pour liner for a shot sleeve of a die-casting system including
a bonding layer within a slot in a shot sleeve substrate and a
refractory metal layer adjacent to the bonding layer. A method of
manufacturing a shot sleeve including forming a slot in the slot
sleeve, laser cladding a bonding layer within the slot, and laser
cladding a refractory metal layer onto the bonding layer.
Inventors: |
KWANG; LIM YUAN; (Singapore,
SG) ; HUI; CHEE YAO; (Singapore, SG) ; CHEN;
ZHENG CHUAN; (Singapore, SG) ; LING; CHARLENE KWAN
YEE; (Singapore, SG) ; BOCHIECHIO; MARIO P.;
(VERNON, CT) ; PANDEY; AWADH B.; (JUPITER, FL)
; SHAH; DILIP M.; (GLASTONBURY, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
UNITED TECHNOLOGIES CORPORATION |
Hartford |
CT |
US |
|
|
Family ID: |
57146635 |
Appl. No.: |
14/695437 |
Filed: |
April 24, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 24/106 20130101;
B22D 17/2023 20130101; B23K 26/34 20130101 |
International
Class: |
B22D 17/20 20060101
B22D017/20; C23C 24/08 20060101 C23C024/08 |
Claims
1. A pour liner for a shot sleeve of a die-casting system,
comprising: a bonding layer within a slot in a shot sleeve
substrate; and a refractory metal layer adjacent to the bonding
layer.
2. The pour liner as recited in claim 1, wherein the pour liner is
circular in cross section.
3. The pour liner as recited in claim 1, wherein the pour liner is
semi-circular in cross-section.
4. The pour liner as recited in claim 1, wherein the bonding layer
and the refractory metal layer are applied via a laser cladding
process.
5. The pour liner as recited in claim 4, wherein the bonding layer
and the refractory metal layer are applied layer-by-layer.
6. The pour liner as recited in claim 1, wherein the bonding layer
includes a nickel alloy.
7. The pour liner as recited in claim 1, wherein the bonding layer
is Inconel.
8. The pour liner as recited in claim 1, wherein the refractory
metal layer includes a tantalum alloy.
9. The pour liner as recited in claim 1, wherein the refractory
metal layer includes a tungsten alloy.
10. A die-casting system, comprising: a shot sleeve having a pour
liner adjacent a pour hole, the pour liner including a bonding
layer.
11. The system as recited in claim 10, wherein the bonding layer is
adjacent to a shot sleeve substrate and a refractory metal layer is
adjacent to the bonding layer.
12. The system as recited in claim 10, wherein the pour liner is
circular in cross-section.
13. The system as recited in claim 10, wherein the pour liner is
semi-circular in cross-section.
14. The system as recited in claim 10, wherein the pour liner is
flush with a cut in the shot sleeve.
15. A method of manufacturing a shot sleeve, comprising: forming a
slot in the slot sleeve; laser cladding a bonding layer within the
slot; and laser cladding a refractory metal layer onto the bonding
layer.
16. The method as recited in claim 15, wherein the bonding layer
includes Inconel.
17. The method as recited in claim 15, wherein the refractory metal
layer includes a tantalum alloy.
18. The method as recited in claim 15, wherein the refractory metal
layer includes a tungsten alloy.
19. The method as recited in claim 15, wherein forming the slot
includes forming the slot adjacent to a pour hole.
20. The method as recited in claim 15, further comprising
subjecting the boding layer to a post weld heat treatment prior to
laser cladding the laser cladding the refractory metal layer onto
the bonding layer.
Description
BACKGROUND
[0001] The present disclosure relates to die-casting and, more
particularly, to an enhanced adherence slot sleeve pour liner for a
shot sleeve.
[0002] In a die-cast tooling system, the plunger tip and the shot
sleeve commonly encounter tool life limits. Shot sleeves typically
encounter three issues which may limit their continued use: thermal
shock by molten metal on the steel part at the pour area; warpage
of the shot sleeve due to temperature differentials created inside
the shot tube; and wear along the inner barrel of the shot sleeve
whilst the piston moves.
[0003] Various methods have been attempted to increase shot sleeve
life. Amongst these re-boring and installation of a larger diameter
piston may resolve wear. However, thermal shock at the pour area
and warpage of the shot tube has not been effectively resolved and
are only exacerbated from high melting point alloys. Thus,
die-casting has often been limited to relatively low melting-point
alloys to avoid thermal shock at the pour area and warpage of the
shot sleeve that may otherwise contribute to jamming of the shot
piston during operation.
[0004] Some die-cast tooling systems utilize a pre-fabricated pour
insert of a refractory alloy welded into the shot sleeve body. The
pour insert effectively reduces the effect of thermal shock and
facilitates rapid heat dissipation compared to typical tool steels.
Since the pour insert is only welded into the tool steel,
replacement is readily facilitated, however, the interface may not
be sufficiently durable for continued die-casting operations.
SUMMARY
[0005] A pour liner for a shot sleeve of a die-casting system
according to one disclosed non-limiting embodiment of the present
disclosure can include a bonding layer within a slot in a shot
sleeve substrate; and a refractory metal layer adjacent to the
bonding layer.
[0006] A further embodiment of the present disclosure may include,
wherein the pour liner is circular in cross section.
[0007] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the pour liner is
semi-circular in cross-section.
[0008] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the bonding layer and
the refractory metal layer are applied via a laser cladding
process.
[0009] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the bonding layer and
the refractory metal layer are applied layer-by-layer.
[0010] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the bonding layer
includes a nickel alloy.
[0011] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the bonding layer is
Inconel.
[0012] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the refractory metal
layer includes a tantalum alloy.
[0013] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the refractory metal
layer includes a tungsten alloy.
[0014] A die-casting system according to one disclosed non-limiting
embodiment of the present disclosure can include a shot sleeve
having a pour liner adjacent a pour hole, the pour liner including
a bonding layer.
[0015] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the bonding layer is
adjacent to a shot sleeve substrate and a refractory metal layer is
adjacent to the bonding layer.
[0016] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the pour liner is
circular in cross-section.
[0017] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the pour liner is
semi-circular in cross-section.
[0018] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the pour liner is flush
with a cut in the shot sleeve.
[0019] A method of manufacturing a shot sleeve according to one
disclosed non-limiting embodiment of the present disclosure can
include forming a slot in the slot sleeve; laser cladding a bonding
layer within the slot; and laser cladding a refractory metal layer
onto the bonding layer.
[0020] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the bonding layer
includes Inconel.
[0021] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the refractory metal
layer includes a tantalum alloy.
[0022] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein the refractory metal
layer includes a tungsten alloy.
[0023] A further embodiment of any of the foregoing embodiments of
the present disclosure may include, wherein forming the slot
includes forming the slot adjacent to a pour hole.
[0024] A further embodiment of any of the foregoing embodiments of
the present disclosure may include comprising subjecting the
bonding layer to a post weld heat treatment prior to laser cladding
the laser cladding the refractory metal layer onto the bonding
layer.
[0025] The foregoing features and elements may be combined in
various combinations without exclusivity, unless expressly
indicated otherwise. These features and elements as well as the
operation thereof will become more apparent in light of the
following description and the accompanying drawings. It should be
understood, however, the following description and drawings are
intended to be exemplary in nature and non-limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Various features will become apparent to those skilled in
the art from the following detailed description of the disclosed
non-limiting embodiment. The drawings that accompany the detailed
description can be briefly described as follows:
[0027] FIG. 1 is a schematic cross-sectional view of a die casting
mold;
[0028] FIG. 2 is a schematic longitudinal sectional view of a shot
sleeve; and
[0029] FIG. 3 is a schematic lateral sectional view of the shot
sleeve according to one disclosed non-limiting embodiment;
[0030] FIG. 4 is a schematic lateral sectional view of the shot
sleeve according to another disclosed non-limiting embodiment;
and
[0031] FIG. 5 is a method for the manufacture of a pour liner for a
shot sleeve according to one disclosed non-limiting embodiment.
DETAILED DESCRIPTION
[0032] FIG. 1 schematically illustrates a die-casting system 10.
The die casting system 10 generally includes a reusable die 12
having a plurality of die elements 14, 16 that function to cast a
component. Although two die elements 14, 16 are depicted, it should
be appreciated that the die 12 could include more die elements, as
well as other parts and configurations. The example die casting
system 10 is illustrative only and could include more or less
sections, parts and/or components including, but not limited to,
horizontal, inclined, and vertical die casting systems.
[0033] The die 12 is assembled and retained at a desired position
via a clamp mechanism 18. Such as a hydraulic, pneumatic,
electromechanical and/or other configurations. The mechanism 18
also separates the die elements 14, 16 subsequent to casting.
[0034] The die elements 14, 16 define internal surfaces that
cooperate to define a die cavity 20. A shot sleeve 24 is in fluid
communication with the die cavity 20 via one or more ports 26
located in the die element 16, the die element 14, or both. A shot
sleeve plunger 28 is received within the shot sleeve 24 and is
moveable between a retracted and injection position (arrow A)
within the shot sleeve 24 by an actuator 30 such as a hydraulic,
pneumatic, electromechanical, or any combination thereof.
[0035] The shot sleeve 24 is positioned to receive a molten metal
from a melting unit 32, such as a crucible, for example. The
melting unit 32 operates to melt an ingot of metallic material to
prepare a molten metal for delivery to the shot sleeve 24,
including but not limited to, vacuum induction melting, electron
beam melting and induction melting. The molten metal is melted by
the melting unit 32 at a location that is separate from the shot
sleeve 24 and the die 12.
[0036] Example molten metals for the die cast component include,
but are not limited to, nickel based super alloys, titanium alloys,
high temperature aluminum alloys, copper based alloys, iron alloys,
molybdenum, tungsten, niobium, or other refractory metals. This
disclosure is not limited to the disclosed alloys, and it should be
appreciated that any high melting temperature material may be
utilized to die cast the component. As used herein, the term "high
melting temperature material" is intended to include materials
having a melting temperature of about 1500.degree. F. (815.degree.
C.) and higher.
[0037] The molten metal is transferred from the melting unit 32 to
the shot sleeve 24 such as via pouring the molten metal into a pour
hole 33 of the shot sleeve 24. A sufficient amount of molten metal
is poured into the shot sleeve 24 to fill the die cavity 20. The
shot sleeve plunger 28 is actuated to inject the molten metal under
pressure from the shot sleeve 24 into the die cavity 20 to cast the
component. Although the casting of a single component is depicted,
the die casting system 10 could be configured to cast multiple
components in a single shot.
[0038] Although not necessary, at least a portion of the die
casting system 10 may be positioned within a vacuum chamber. The
vacuum chamber provides a non-reactive environment for the die
casting system 10 that reduces reaction, contamination, or other
conditions that could detrimentally affect the quality of the cast
component, such as excess porosity of the die cast component that
can occur as a result of ingressed air during molten metal
solidification.
[0039] With reference to FIG. 2, the shot sleeve 24 adjacent to the
pour hole 33 includes a pour liner 40 within a shot sleeve
substrate 50. The pour liner 40 utilizes powdered refractory
material deposited metallurgically and fused layer-by-layer into a
slot 42 machined into an inner diameter of the shot sleeve
substrate 50 axially located adjacent to the pour hole 33. In one
embodiment, the slot 46 extends for about 180 degrees opposite the
pour hole 33 (FIG. 3). In another embodiment, the slot 42 extends
for about 360 degrees at the axial location of the pour hole 33
(FIG. 4).
[0040] The pour liner 40 is formed in a multi-layer manner in which
a bonding layer 44 such as Inconel e.g. IN625, is applied to the
exposed tool steel in the slot 42, then a refractory metal layer 46
such as tantalum or tungsten alloys is applied to the bonding layer
44. In one example, the bonding layer is about 3.8 mm thick and the
refractory metal layer is about 0.2 mm thick. The bonding layer 44
provides a buffer against deleterious alloy diffusion from the
highly alloyed base tool steel substrate into the refractory metal
powder layer 46. The refractory metal powder layer 46 is thereby
provided with increased adherence.
[0041] With reference to FIG. 5, a method 100 to manufacture the
shot sleeve 24 initially includes machining the slot 42 (step 102).
In one example, the slot 42 is either a semicircular (FIG. 3) or a
circular (FIG. 4) slot that extends for about six inches and is
located adjacent to the pour hole 33.
[0042] Next, the bonding layer 44 is applied (step 104). In one
embodiment, the bonding layer 44 may be applied via a laser
cladding process in which a nickel alloy powder, such as IN625
powder is communicated into the slot 42 while interacting with an
impinging laser beam. The laser melts the powder and the melt is
fused into the base metal substrate 50 of the shot sleeve 24. The
powder is thereby solidified and built-up layer-by-layer to a
desired thickness leaving a final clad thickness awaiting
deposit.
[0043] The bonding layer 44 may then be subjected to a post weld
heat treatment (step 106). The optional post weld heat treatment
may be performed to reduce the thermal stress before the final
refractory metal layer 46 clad.
[0044] The refractory metal layer 46 is then applied (step 108). As
with the bonding layer 44, the refractory metal layer 46 may be
applied via a laser cladding process. In another embodiment, a
separate nozzle configuration may be utilized to pre-place the
refractory metal powder mixed with binder material.
[0045] The refractory metal layer 46 clad forms relatively fine
grain sizes of tunable hardness by laser beam operation adjustments
and the interplay between the power type power, feed rate, and/or
time rastering layer-by-layer. Layer-by-layer, the refractory metal
layer 46 may be built up until proud of the slot 42. The bonding
layer 44 provides a relatively stronger joint since the layers are
metallurgical bonded layer by layer and reduced crack
susceptibility for improved adherence due to the nickel buffering
layer operating as a diffusion barrier against the highly alloyed
tool steel.
[0046] Finally, the shot sleeve 24 may be machined such as by being
honed to size to yield the localized refractory metal clad area
within the shot sleeve 24 (step 110).
[0047] The refractory metal lined shot sleeve provides enhanced
tool life due to reduced thermal fatigue cracks at the pour area.
The refractory metal lined shot sleeve 24 also avoids potential
fluid/oil line leakage as cracks are reduced and wash-out effects
at the pour area are avoided. The powdered laser clad process
further permits tunable properties at the pour area as well as
repair.
[0048] The use of the terms "a," "an," "the," and similar
references in the context of description (especially in the context
of the following claims) are to be construed to cover both the
singular and the plural, unless otherwise indicated herein or
specifically contradicted by context. The modifier "about" used in
connection with a quantity is inclusive of the stated value and has
the meaning dictated by the context (e.g., it includes the degree
of error associated with measurement of the particular quantity).
All ranges disclosed herein are inclusive of the endpoints, and the
endpoints are independently combinable with each other. It should
be appreciated that relative positional terms such as "forward,"
"aft," "upper," "lower," "above," "below," and the like are with
reference to the normal operational attitude of the vehicle and
should not be considered otherwise limiting.
[0049] Although the different non-limiting embodiments have
specific illustrated components, the embodiments of this invention
are not limited to those particular combinations. It is possible to
use some of the components or features from any of the non-limiting
embodiments in combination with features or components from any of
the other non-limiting embodiments.
[0050] It should be appreciated that like reference numerals
identify corresponding or similar elements throughout the several
drawings. It should also be appreciated that although a particular
component arrangement is disclosed in the illustrated embodiment,
other arrangements will benefit herefrom.
[0051] Although particular step sequences are shown, described, and
claimed, it should be understood that steps may be performed in any
order, separated or combined unless otherwise indicated and will
still benefit from the present disclosure.
[0052] The foregoing description is exemplary rather than defined
by the limitations within. Various non-limiting embodiments are
disclosed herein, however, one of ordinary skill in the art would
recognize that various modifications and variations in light of the
above teachings will fall within the scope of the appended claims.
It is therefore to be appreciated that within the scope of the
appended claims, the disclosure may be practiced other than as
specifically described. For that reason the appended claims should
be studied to determine true scope and content.
* * * * *