U.S. patent application number 15/348136 was filed with the patent office on 2018-05-10 for additive manufacture of optical components.
The applicant listed for this patent is Goodrich Corporation. Invention is credited to Daniel E. Dunn, Matthew J. East, Kramer Harrison, Bari M. Southard.
Application Number | 20180127296 15/348136 |
Document ID | / |
Family ID | 60293892 |
Filed Date | 2018-05-10 |
United States Patent
Application |
20180127296 |
Kind Code |
A1 |
Southard; Bari M. ; et
al. |
May 10, 2018 |
ADDITIVE MANUFACTURE OF OPTICAL COMPONENTS
Abstract
A method of forming an optical component includes depositing
slurry that includes glass powder material onto a facesheet and
fusing the glass powder material to a facesheet to form a first
core material layer on the facesheet. The method also includes
successively fusing glass powder material in a plurality of
additional core material layers to build a core material structure
on the facesheet. The method can include selectively depositing
slurry including glass powder material over only a portion of at
least one of the facesheet, the first core material layer, and/or
the one of the additional core material layers. Depositing the
slurry can include extruding the slurry from an extruder.
Inventors: |
Southard; Bari M.;
(Bridgewater, CT) ; East; Matthew J.; (Danbury,
CT) ; Dunn; Daniel E.; (Bethel, CT) ;
Harrison; Kramer; (Norwalk, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Goodrich Corporation |
Charlotte |
NC |
US |
|
|
Family ID: |
60293892 |
Appl. No.: |
15/348136 |
Filed: |
November 10, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C03C 2218/32 20130101;
C03B 19/06 20130101; C03C 17/3417 20130101; B33Y 80/00 20141201;
C03B 19/01 20130101; C03C 17/04 20130101; C03B 2201/42 20130101;
G02B 5/10 20130101; C03C 2218/35 20130101; C03C 8/02 20130101; C03C
23/0025 20130101; B33Y 10/00 20141201 |
International
Class: |
C03B 19/01 20060101
C03B019/01; B33Y 10/00 20060101 B33Y010/00; B33Y 80/00 20060101
B33Y080/00; C03C 8/02 20060101 C03C008/02; G02B 5/10 20060101
G02B005/10 |
Claims
1. A method of forming an optical component comprising: depositing
slurry including glass powder material onto a facesheet; fusing the
glass powder material to the facesheet to form a first core
material layer on the facesheet; and successively depositing and
fusing glass powder material in at least one additional core
material layer to build a core material structure on the
facesheet.
2. The method as recited in claim 1, wherein at least one of
depositing slurry including glass powder material and successively
fusing glass powder material includes: selectively depositing
slurry including glass powder material over only a portion of at
least one of the facesheet, the first core material layer, and/or
the one of the additional core material layers.
3. The method as recited in claim 1, wherein depositing the slurry
includes extruding the slurry from an extruder.
4. The method as recited in claim 1, wherein fusing glass powder
material includes fusing low expansion glass powder into low
expansion glass with a laser.
5. The method as recited in claim 4, wherein fusing glass powder
material includes fusing low expansion titania-silica glass powder
into low expansion titania-silica glass.
6. The method as recited in claim 1, wherein fusing glass powder
material to a facesheet includes fusing glass powder material to a
facesheet that is contoured for optical properties.
7. The method as recited in claim 1, further comprising positioning
the facesheet on a mandrel prior to fusing glass powder material to
the facesheet.
8. The method as recited in claim 1, wherein fusing glass powder
material to the facesheet includes fusing the glass powder material
to a polishable surface of the facesheet.
9. The method as recited in claim 1, wherein successively fusing
glass powder material includes forming a mirror substrate.
10. The method as recited in claim 9, wherein forming a mirror
substrate includes forming an optimal three-dimensional mirror
topology that minimizes the mass of mirror substrate while
providing a level of stiffness and stability above a predetermined
minimum requirement.
11. The method as recited in claim 1, wherein successively fusing
glass powder material includes varying material properties in
successive layers.
12. An optical component comprising: a glass facesheet; a first
layer of low expansion glass fused to the glass facesheet; and at
least one successively fused layer forming a core material
structure on an assembly that includes the facesheet and the first
layer.
13. The optical component as recited in claim 12, wherein the first
layer and the at least one successively fused layer include fused
low expansion glass powder material.
14. The optical component as recited in claim 13, wherein the fused
low expansion glass powder material includes fused low expansion
titania-silica glass powder.
15. The optical component as recited in claim 12, wherein the
facesheet is contoured for optical properties in at least one of
two-dimensions or three-dimensions.
16. The optical component as recited in claim 1, wherein the
facesheet includes a polishable surface, wherein the first layer is
fused to the polishable surface of the facesheet.
17. The optical component as recited in claim 1, wherein the
facesheet, first layer, and successively fused layers form a mirror
substrate.
18. The optical component as recited in claim 17, wherein the
mirror substrate includes an optimal three-dimensional mirror
topology that minimizes the mass of mirror substrate while
providing a level of stiffness and stability above a predetermined
minimum requirement.
19. The optical component as recited in claim 12, wherein the
plurality of successively fused layers includes glass material with
material properties that vary in successive layers.
20. The optical component as recited in claim 12, wherein the
plurality of successively fused layers includes glass material with
material properties that vary based on position within the core
material structure.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present disclosure relates to optics and additive
manufacturing, and more particularly to additively manufacturing
optics, e.g., from low expansion glass.
2. Description of Related Art
[0002] Conventional lightweight glass mirror substrates are
generated with subtractive manufacturing, milling, grinding,
polishing, or etching away material from a large glass boule. These
processes can create a stiff, lightweight glass structure with a
precisely shaped optical surface, which remains stable under
thermal and mechanical loads. But because glass is fragile, it is
challenging to manufacture many small, intricate features with
these conventional processes, and such intricate features can be
important to manufacturing lightweight optics.
[0003] The conventional techniques have been considered
satisfactory for their intended purpose. However, there is an ever
present need for improved manufacturing of glass optics such as
mirror substrates. This disclosure provides a solution for this
problem.
SUMMARY OF THE INVENTION
[0004] A method of forming an optical component includes depositing
slurry including glass powder material onto a facesheet and fusing
the glass powder material to a facesheet to form a first core
material layer on the facesheet. The method also includes
successively fusing glass powder material in a plurality of
additional core material layers to build a core material structure
on the facesheet.
[0005] The method can include positioning the facesheet on a
mandrel prior to fusing glass powder material to the facesheet.
Fusing glass powder material to the facesheet can include fusing
the glass powder material to a polishable surface of the facesheet.
At least one of depositing slurry including glass powder material
and successively fusing glass powder material in a plurality of
additional core material layers can include selectively depositing
slurry including glass powder material over only a portion of at
least one of the facesheet, the first core material layer, and/or
the one of the additional core material layers. Depositing the
slurry can include extruding the slurry from an extruder. Fusing
glass powder material can include fusing low expansion glass powder
into low expansion glass, e.g., with a laser. Fusing glass powder
material can include fusing low expansion titania-silica glass
powder into low expansion titania-silica glass. Fusing glass powder
material to a facesheet can include fusing glass powder material to
a facesheet that is contoured for optical properties.
[0006] Successively fusing glass powder material can include
forming a mirror substrate. Forming a mirror substrate can include
forming an optimal three-dimensional mirror topology that minimizes
the mass of mirror substrate while providing a level of stiffness
and stability above a predetermined minimum requirement.
Successively fusing glass powder material can include varying
material properties in successive layers and/or varying material
properties based on position in the successive layers.
[0007] An optical component includes a glass facesheet. A first
layer of low expansion glass is fused to the glass facesheet. A
plurality of successively fused layers form a core material
structure on an assembly that includes the facesheet and the first
layer.
[0008] The facesheet can be contoured for optical properties in at
least one of two-dimensions or three-dimensions. The facesheet can
include a polishable surface, wherein the first layer is fused to
the polishable surface of the facesheet. The first layer and the
plurality of successively fused layers can include fused low
expansion glass powder material, e.g., low expansion titania-silica
glass powder. The facesheet, first layer, and successively fused
layers can form a mirror substrate. The mirror substrate can
include an optimal three-dimensional mirror topology that minimizes
the mass of mirror substrate while providing a level of stiffness
and stability above a predetermined minimum requirement. The
plurality of successively fused layers can include glass material
with material properties that vary in successive layers and or that
vary based on position within the core material structure.
[0009] These and other features of the systems and methods of the
subject disclosure will become more readily apparent to those
skilled in the art from the following detailed description of the
preferred embodiments taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] So that those skilled in the art to which the subject
disclosure appertains will readily understand how to make and use
the devices and methods of the subject disclosure without undue
experimentation, preferred embodiments thereof will be described in
detail herein below with reference to certain figures, wherein:
[0011] FIG. 1 is a schematic side elevation view of an exemplary
embodiment of a mirror substrate constructed in accordance with the
present disclosure, showing the mandrel and the facesheet with
successive layers of additively manufactured core material
structure deposited on the facesheet;
[0012] FIG. 2 is a schematic perspective view of the mirror
substrate of FIG. 1, showing the extruder selectively depositing a
slurry of glass powder material; and
[0013] FIG. 3 is a schematic plan view of the mirror substrate of
FIG. 1, showing a laser beam fusing the powder material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Reference will now be made to the drawings wherein like
reference numerals identify similar structural features or aspects
of the subject disclosure. For purposes of explanation and
illustration, and not limitation, a partial view of an exemplary
embodiment of an optical component in accordance with the
disclosure is shown in FIG. 1 and is designated generally by
reference character 100. Other embodiments of optical components in
accordance with the disclosure, or aspects thereof, are provided in
FIGS. 2-3, as will be described. The systems and methods described
herein can be used to additively manufacture optical components
such as mirror substrates from low thermal expansion glass.
[0015] FIG. 1 shows an optical component 100, e.g., a mirror
substrate, on a mandrel 102. A method of forming the optical
component 100 includes positioning a preformed glass facesheet 104
on the mandrel 102. The facesheet 104 can be made of titania-silica
glass, can be relatively thin, and is contoured for optical
properties, e.g. two- or three-dimensionally contoured to provide a
desired or predetermined mirror contour. A glass powder material is
fused to a polishable surface 114 of the facesheet 104 to form a
first core material layer 106 on the facesheet 104. Glass powder
material is then successively fused in a plurality of additional
core material layers 108 to build a core material structure 110 on
the facesheet 104. The final layer 112 is fused at the surface of
core material structure 110 opposite the facesheet 104 from the
first layer 106. The facesheet 104 becomes part of the finished
optical component 100.
[0016] With reference now to FIG. 2, the method includes depositing
liquid slurry that includes the glass powder material using an
articulated extruder 124 to deposit the slurry onto the polishable
surface 114 of the facesheet 104. Extruder 124 is articulated by
conveyor system 126 for selectively depositing the slurry over only
a portion of at least one of the facesheet 104, the first core
material layer 106, and/or the one of the additional core material
layers 108. In other words, extruder 124 extrudes slurry onto the
top most surface of the assembly 115 that includes facesheet 104,
the first core material layer 106, and/or one or more of the
additional core material layers 108, as oriented in FIGS. 1-2. The
slurry can include the glass powder material suspended in a liquid
gel, water, or suitable fluid for extrusion through nozzle 128 for
precise selective depositing or printing onto the assembly 115.
After the slurry is deposited, it can be dried to leave behind a
dried powder of the glass material ready for fusing to the assembly
115. The glass powder material can be configured to form a low
expansion glass material when the powder is fused, for example, low
expansion titania-silica glass powder can be fused into low
expansion titania-silica glass.
[0017] Referring now to FIG. 3, each such layer of powder is fused
to the assembly 115 to form the cross-section of the desired
geometry into the core material structure 110. The fusion can be
achieved by using a laser beam 116. In FIG. 3, the laser beam 116
is shown schematically fusing the portion 118 of the deposited
powder covering assembly 115 to form a layer of fused glass only in
the triangle shape shown. The direction of movement of laser beam
116 around the pattern of the triangle is indicated by the large
arrow in FIG. 3. The portion 120 of the powder that is about to be
fused by laser beam 116 is shown schematically in FIG. 3.
Mechanical abrasion grinding can optionally be used to prepare the
assembly 115 after fusing a given layer prior to depositing the
slurry for the next layer, e.g., to ensure that the fused layer is
uniform in thickness.
[0018] This technique allows for forming a mirror substrate, or
other optical component, with an optimal three-dimensional topology
that minimizes the mass of mirror substrate while providing a level
of stiffness and stability above a predetermined minimum
requirement. Successively fusing layers as described herein can
include fusing glass powder material so as to vary material
properties in successive layers and/or varying material properties
based on position in a given layer. For example, the triangular
portion 118 in FIG. 2 can be formed of glass with a first set of
material properties, and the remaining portions 122 of the surface
of assembly 115 can be formed of a glass with a second set of
material properties so that a given layer 108 has different sets of
material properties within itself as a function of location within
that layer 108.
[0019] Unlike conventional additive manufacturing, where a part is
printed on a build plate and later removed therefrom, the facesheet
104 serves as a build plate and also becomes part of the finished
product. As a finishing process, the final layer 112 and or
opposite surface 130 of the face sheet 104 shown in FIG. 1 can be
polished and coated.
[0020] The methods and systems of the present disclosure, as
described above and shown in the drawings, provide for optical
components with superior properties potentially including very
intricate features, optimal three-dimensional geometric topologies,
including amorphous topologies with smaller more intricate features
than can be reliably produced using conventional techniques, to
minimize mass, e.g., of mirror substrates, while achieving required
stiffness and stability for given applications and loads. It is
also possible to provide quicker fabrication of low expansion glass
using techniques disclosed herein, compared to conventional
techniques, and it is possible to make larger glass mirror
substrates than in convention techniques. With respect to allowing
making larger glass mirror substrates than are possible with
conventional techniques using build plates, this stems from the
fact that under conventional techniques, the high temperatures of
additive manufacturing can case thermal stresses during manufacture
that warp a part and can cause it to peel off from the build-plate.
This peeling process limits how large a component can be
manufactured under conventional additive manufacturing techniques,
but it is not a limitation for techniques disclosed herein. The
thermal expansion behavior and visco-elastic behavior of
titania-silica glass at high temperatures is a key enabler of
larger additively manufactured structures. The fusing of the
additively manufactured layers to the build plate is another key
enabler of larger additively manufactured structures.
[0021] While the apparatus and methods of the subject disclosure
have been shown and described with reference to preferred
embodiments, those skilled in the art will readily appreciate that
changes and/or modifications may be made thereto without departing
from the scope of the subject disclosure.
* * * * *