U.S. patent application number 09/832128 was filed with the patent office on 2002-11-21 for silicon aluminum alloy of prealloyed powder and method of manufacture.
Invention is credited to McGeever, Jocelyne O., McTiernan, Brian J., Peretti, Michael W..
Application Number | 20020170389 09/832128 |
Document ID | / |
Family ID | 25260766 |
Filed Date | 2002-11-21 |
United States Patent
Application |
20020170389 |
Kind Code |
A1 |
McTiernan, Brian J. ; et
al. |
November 21, 2002 |
SILICON ALUMINUM ALLOY OF PREALLOYED POWDER AND METHOD OF
MANUFACTURE
Abstract
A silicon base binary alloy of prealloyed powder having less
than 10% aluminum, excluding zero. The alloy may be in the form of
gas atomized prealloyed powder, which powder may be consolidated to
form an article. Preferably, the article is a sputtering
target.
Inventors: |
McTiernan, Brian J.;
(Robinson Township, PA) ; Peretti, Michael W.;
(Finleyville, PA) ; McGeever, Jocelyne O.; (Mars,
PA) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT &
DUNNER LLP
1300 I STREET, NW
WASHINGTON
DC
20005
US
|
Family ID: |
25260766 |
Appl. No.: |
09/832128 |
Filed: |
April 11, 2001 |
Current U.S.
Class: |
75/338 ;
420/578 |
Current CPC
Class: |
B22F 2999/00 20130101;
C22C 29/18 20130101; B22F 2999/00 20130101; C23C 14/3414 20130101;
C22C 1/04 20130101; B22F 9/082 20130101; C22C 1/04 20130101 |
Class at
Publication: |
75/338 ;
420/578 |
International
Class: |
B22F 009/08 |
Claims
What is claimed is:
1. A binary alloy of prealloyed powder consisting essentially of,
in weight percent, less than 10 Al, excluding zero, and balance
Si.
2. A binary alloy of prealloyed powder consisting essentially of,
in weight percent, 6 maximum Al, excluding zero, and balance
Si.
3. A binary alloy of prealloyed powder consisting essentially of,
in weight percent, about 6 Al and balance Si.
4. The alloy of claims 1, 2 or 3 in the form of gas atomized,
prealloyed powder.
5. The alloy of claims 1, 2 or 3 in the form of a consolidated
article of gas atomized, prealloyed powder of said alloy.
6. The consolidated article of claim 5, wherein said article is
characterized by a microstructure substantially free of unalloyed
Si and Al.
7. A method for producing a binary alloy consisting essentially of,
in weight percent, less than 10 Al, excluding zero, and balance Si,
said method comprising: producing a heat of said alloy; and gas
atomizing said heat to produce prealloyed powder particles of said
alloy.
8. The method of claim 7, wherein said heat is produced by vacuum
induction melting.
9. The method of claims 7 or 8, wherein said alloy consists
essentially of, in weight percent, 6 maximum Al, excluding zero,
and balance Si.
10. The method of claims 7 or 8, wherein said alloy consists
essentially of, in weight percent, about 6 Al and balance Si.
Description
DESCRIPTION OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a silicon-base alloy of prealloyed
powder containing aluminum and is preferably in the form of gas
atomized prealloyed powder suitable for consolidation to produce
sputtering targets.
[0003] 2. Background of the Invention
[0004] Planar and rotatable sputtering targets of a silicon base
alloy containing aluminum have conventionally been produced using
plasma spray techniques with elemental blended powder used as the
feed stock. These targets are primarily used to provide conductive,
scratch resistant, and glare resistant coatings to video flat panel
displays as well as automotive glass.
[0005] These conventional targets are deficient in that the
compositions thereof are not uniform as a result of the use of
elemental powder, which results in non-uniformity of the finished,
coated surface produced therefrom.
[0006] It is accordingly a primary object of the present invention
to provide a binary silicon base alloy of prealloyed powder
containing aluminum which may be used in the production of
sputtering targets that provides advantages both in uniformity of
composition and ease of target manufacture over conventional
practices.
SUMMARY OF THE INVENTION
[0007] In accordance with the invention, a binary silicon-base
alloy of prealloyed powder is provided having, in weight percent,
less than 10 aluminum, excluding zero. Preferably, the alloy has 6%
maximum aluminum, excluding zero, and more preferably, the alloy
has about 6% aluminum.
[0008] The alloy may be in the form of gas atomized, prealloyed
powder. This powder may be consolidated to form a consolidated
article therefrom, which may be a sputtering target.
[0009] By the use of the practice of the invention, the
consolidated article is characterized by a microstructure
substantially free of unalloyed silicon and aluminum. This provides
a high degree of uniformity throughout the structure of the
article.
[0010] The binary alloy of prealloyed powder in accordance with the
invention may be produced from a heat of the alloy that is gas
atomized to produce prealloyed powder particles therefrom. The heat
may be produced by vacuum induction melting.
DETAILED DESCRIPTION OF THE INVENTION
[0011] In accordance with the invention, samples of two gas
atomized heats were tested with respect to spray evaluation. One
was made using conventional practice with blended elemental powder
and one was made using argon gas atomized silicon aluminum powder
in accordance with the invention and identified as L1228. The
compositions of these powders are shown in Table 1.
1TABLE 1 Chemistry of Si-6% Al Powders Si Al Fe Zr Cu P Mn Cr C O N
S Blend Bal. 6.13 0.010 <0.005 <0.003 <0.005 <0.005
<0.005 0.010 0.051 0.002 <0.001 Elem. Pwdr. CRC Bal. 5.70
0.014 <0.001 <0.001 <0.005 <0.001 <0.005 0.007 0.020
0.002 <0.001 L1228 CRC Bal. 5.79 0.043 <0.013 <0.001
<0.005 <0.001 <0.005 0.009 0.020 0.002 <0.001 L1229
[0012] The plasma spray coupons were cut and polished for
examination using a scanning electron microscope (SEM) and energy
dispersive X-ray analysis.
[0013] The examination demonstrated that the deposited layer made
with prealloyed powder (L1228) was much more uniformed than that
deposited from blended elemental powder. Specifically, with the
elemental blended powder the deposited material was non-uniform in
chemistry and aluminum-rich areas were present. With the deposited
layer made with the prealloyed powder, the chemistry was uniform
throughout and there was no measurable dilution from the original
prealloyed powder. Consequently, the structure of the deposit
resulting from prealloyed powder was much more uniform than the
conventional product made with blended elemental powder. In
addition, it did not contain any areas of free silicon crystals or
pure aluminum which would have electrically conductive or
scratch-resistant properties substantially different from the
remainder of the deposit.
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