U.S. patent number 3,742,585 [Application Number 05/101,954] was granted by the patent office on 1973-07-03 for method of manufacturing strip from metal powder.
This patent grant is currently assigned to Homogeneous Metals, Inc.. Invention is credited to Joseph M. Wentzell.
United States Patent |
3,742,585 |
Wentzell |
July 3, 1973 |
METHOD OF MANUFACTURING STRIP FROM METAL POWDER
Abstract
A method is provided for forming metal strip from metal powders
by spraying the powder as molten metal onto a cooled moving metal
foil and thereafter consolidating the foil and sprayed metal by
applying pressure.
Inventors: |
Wentzell; Joseph M. (Remsen,
NY) |
Assignee: |
Homogeneous Metals, Inc.
(Herkimer, NY)
|
Family
ID: |
22287361 |
Appl.
No.: |
05/101,954 |
Filed: |
December 28, 1970 |
Current U.S.
Class: |
29/423;
29/DIG.39; 29/527.7; 164/46; 164/131; 427/398.2; 427/422; 427/427;
29/527.2; 29/898.12; 164/76.1; 427/398.4; 427/424; 427/455 |
Current CPC
Class: |
C23C
4/14 (20130101); C23C 4/137 (20160101); Y10T
29/49705 (20150115); Y10T 29/49982 (20150115); Y10S
29/039 (20130101); Y10T 29/4981 (20150115); Y10T
29/49991 (20150115) |
Current International
Class: |
C23C
4/14 (20060101); C23C 4/12 (20060101); B23p
017/00 () |
Field of
Search: |
;29/527.2,527.7,DIG.39,149.5S,423 ;164/46 ;117/105,105.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lanham; Charles W.
Assistant Examiner: Reiley, III; D. C.
Claims
I claim:
1. A method of forming strip from metal powders comprising the
steps of
a. converting a metal powder to a molten metal spray,
b. applying the molten metal spray in an inert atmosphere to a
moving metal foil in a substantially uniform layer to form a major
component of the combined thickness,
c. cooling the metal foil and molten spray applied thereto to
solidify said molten spray while in said inert atmosphere, and
d. consolidating said foil and sprayed metal by applying pressure
thereto.
2. A method as claimed in claim 1 wherein the foil is cooled
simultaneously with the application of the molten spray
thereto.
3. A method as claimed in claim 1 wherein the foil is coated with
metal spray while changing direction of the foil.
4. A method as claimed in claim 1 wherein the metal foil is a
member selected from the group aluminum, nickel, copper and
iron.
5. A method as claimed in claim 1 wherein the metal is consolidated
by pressure rolling.
6. A method claimed in claim 1 wherein the metal powder is passed
through a plasma gun to form a molten spray of metal.
7. A method as claimed in claim 1 wherein the foil is removed by
etching after consolidation of the metal.
8. A method as claimed in claim 1 wherein the foil is passed over a
water cooled roll in an inert atmosphere and the molten metal
sprayed onto the foil while the foil is on the water cooled roll.
Description
This invention relates to methods of manufacturing strip from metal
powder and particularly to a method of making superalloy strip from
powder, although the method will apply to other alloys as well.
Normally the metals known as superalloys, i.e., alloys of iron,
nickel or cobalt which will maintain usable mechanical properties
at elevated temperatures, are cast into ingots which are then
either forged or bloomed into slabs, cut and conditioned, rolled
into either bands or plates, conditioned and then finally rolled
into strip and cut. There are several heat treatments necessary
throughout the process and a final heat treatment dependent on the
customers requirements. All of this costs time and money. Perhaps
more important is the fact that this large amount of hot working
tends to deplete boron from superalloys through oxidation. Boron is
essential to stress rupture life at elevated temperature.
Sheet and strip of nickel, aluminum and iron have been rolled
directly from metal powder by feeding the powder through a mill
with its rolls in a horizontal plane. When rolling strip in this
fashion it is necessary that the green strength of the strip be
sufficient to allow subsequent processing. This means that the
powder must have a special configuration conducive to providing
high green strength. Superalloy powder having high purity is
generally made by a dry process which results in spherical powder
having poor cold compactability lacking the special configuration
necessary to provide green strength.
I have invented a method of making metal strip from metal powder
which makes it possible to form strip from powder without regard to
its shape. In my method I feed the metal powder through a plasma
gun or similar metallizing gun onto a substrate of aluminum, copper
or iron strip or foil, the foil being in intimate contact with a
cooling element at the time the hot metal particles are sprayed
onto the substrate. The metal spraying operation is carried out in
an inert atmosphere such as in an inert gas purged chamber.
Preferably the sprayed foil is cold rolled to a predetermined
reduction and then resprayed if greater thickness is desired. The
amount of spray applied and the amount of cold rolling are
dependent upon the particular alloy and the desired thickness. Each
subsequent spraying or metallizing after rolling will stress
relieve the strip. Since all heat treatment is carried out in an
inert atmosphere oxidation is eliminated. The substrate may be
removed from the finished strip by preferential etching using for
example hydroxide for aluminum foil and nitric acid for copper or
iron.
In the foregoing general description of my invention I have set out
certain objects, purposes and advantages of my invention. Other
objects, purposes and advantages will be apparent from a
consideration of the following description and the accompanying
drawings in which:
FIG. 1 is a schematic section through an apparatus for carrying out
the practice of this invention, and
FIG. 2 is a section through a strip made from metal powder
according to my invention.
Referring to the drawings I have illustrated a sheet of foil 10
being delivered from coil 11 through a chevron seal 12 into the
interior of chamber 13 where it passes over a water cooled roll 14.
The foil 10 is sprayed with molten superalloy 15 from a plasma gun
16 supplied with powdered superalloy from a hopper 17. The molten
superalloy 15 solidifies on the foil 10 to form a layer of
superalloy which is passed between pressure rolls 18 to cold roll
the newly formed superalloy strip 15.
If a greater thickness of strip 15 is desired than can be applied
with one pass in front of plasma gun 16, then the coating operation
is simply repeated as many times as is necessary. The spraying of
molten superalloy onto the strip 15 will stress relieve the
previously formed layer 15 without danger of oxidation.
If the substrate 10 is to be removed the composite strip is passed
through an appropriate etch solution to dissolve it away from the
superalloy strip 15 after cold rolling.
In the foregoing specification I have set out certain preferred
practices and embodiments of my invention, however, it will be
understood that this invention may be otherwise embodied.
* * * * *