Patent US4295808A successfully refreshed from Google Patents.
US4295808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the production of high-purity metal powder by means of electron beam heating
Assignee: Balzers und Leybold Deutschland Holding AG
•
Filing: 1979-10-15
•
Granted: 1981-10-20
•
Expires: 1999-10-15
Abstract
Abstract High-purity metal powder is made by the electron beam melting of a starting material in rod form in a vacuum wherein the molten metal is momentarily caught on a spinning plate rotating at high speed and flung therefrom and thereafter solidified by cooling. The metal on the spinning plate is bombarded with an electron beam that is so focused and periodically deflected that its focal spot is many times smaller than the diameter of the spinning plate. The beam deflection between the rotational center of the spinning plate and its marginal area is performed such that the spinning plate is scanned in a zone that extends radially of the axis of rotation of the spinning plate and is small in relation to its diameter. Cooling of the metal particles to the point of solidification is accomplished by radiation loss.
Inventors
- 👤 Herbert Stephan
- 👤 Hans Aichert
- 👤 Joseph Heimerl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:40
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/14; B22F9/06; B22F9/08; B22F9/10; B22F9/082; B22F2009/084
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
247 words
An apparatus for making high-purity metal powder from high purity metal while maintaining the initial high purity of the starting material, comprising: a. a circular plate having a given diameter and a circumferential marginal area and means for rotating same at a high speed about a vertical axis of rotation corresponding to the center of the plate; b. means for electron beam melting high purity metal starting material in rod form in vacuo into molten metal droplets directed onto the circular plate; c. means for producing an electron beam focusable to a given focal spot on the plate and for focusing the focal spot such that its diameter is many times smaller than the given diameter of the plate and deflecting the beam between the rotational center of the spinning plate and the marginal area to effect the scanning of the plate in a zone that extends radially of the axis of rotation of the plate to said marginal area when the plate is spinning to direct the molten metal droplets by centrifugal force from the plate when it is spinning in a controlled manner within a fixed narrow angular portion of the circumference of the spinning plate to define a fixed narrow angular range of flight paths of the molten metal droplets leaving the plate; and d. means for collecting the metal particles formed from the droplets undergoing cooling and solidification due to loss of heat due to radiation during flight to form the metal powder.
Claim 2
Independent Claim
247 words
An apparatus for making high-purity metal powder from high purity metal while maintaining the initial high purity of the starting material, comprising: a. a circular plate having a given diameter and a circumferential marginal area and means for rotating same at a high speed about a vertical axis of rotation corresponding to the center of the plate; b. means for electron beam melting high purity metal starting material in rod form in vacuo into molten metal droplets directed onto the circular plate; c. means for producing an electron beam focusable to a given focal spot on the plate and for focusing the focal spot such that its diameter is many times smaller than the given diameter of the plate and deflecting the beam between the rotational center of the spinning plate and the marginal area to effect the scanning of the plate in a zone that extends radially of the axis of rotation of the plate to said marginal area when the plate is spinning to direct the molten metal droplets by centrifugal force from the plate when it is spinning in a controlled manner within a fixed narrow angular portion of the circumference of the spinning plate to define a fixed narrow angular range of flight paths of the molten metal droplets leaving the plate; and d. means for collecting the metal particles formed from the droplets undergoing cooling and solidification due to loss of heat due to radiation during flight to form the metal powder.
Claim 3
Dependent Claim
53 words
Apparatus of claim 1, wherein the spinnable plate has on its upper side a substantially cup-shaped, central recess, wherein the marginal area is a substantially hollow conical zone adjoining the rim of the recess and having a smaller angle of inclination than the angel of inclination of the recess immediately preceding the rim.
Claim 4
Dependent Claim
61 words
Apparatus of claim 2, wherein the diameter D i of the rim is smaller by between 20 to 60 mm than the outside diameter D of the spinning plate, the radius R of the cup-shaped recess is between 0.6 and 1.0 times D i , and the angle of inclination of the marginal area is between 5 degrees and 60 degrees.
Claim 5
Dependent Claim
31 words
Apparatus of claim 2, wherein the recess is disposed in a replaceable top part of the spinning plate, and the receptacle for the top part is provided with a coolant passage.
Claim 6
Dependent Claim
42 words
Apparatus of claim 1, wherein the means for melting comprises vacuum chamber means having an extension chamber which can receive the rod-like starting material and means for shutting off the extension chamber with respect to the vacuum chamber comprising a shut-off valve.
Claim 7
Dependent Claim
42 words
Apparatus of claim 1, wherein the means for melting comprises an electron beam-heated intermediate reservoir disposed between the rod-shaped starting material and the spinnable plate in the path of the molten starting material and having an overflow spout above the spinnable plate.
Claim 8
Dependent Claim
35 words
Apparatus of claim 1, wherein the melting means comprises a vacuum chamber and the collecting means comprises a powder collecting chamber and a jogging conveyor disposed between the vacuum chamber and the powder collecting container.
Claim 9
Dependent Claim
12 words
Apparatus of claim 7, wherein the jogging conveyor comprises a spiral conveyor.
Claim 10
Dependent Claim
58 words
Apparatus of claim 1, wherein the means for rotating the plate drives same at a rotatory speed between 3,600 and 15,000 rpm, and wherein the means producing the electron beam periodically deflects same with a frequency between 30 and 100 Hz and focuses the focal spot diameter between 1/10 and 1/100 of the diameter of the spinning plate.
Claim 11
Dependent Claim
53 words
Apparatus of claim 1, wherein the means for producing the beam includes means for producing a step-wise deflection voltage elevation to form briefly dwelling focal spots arranged radially of the axis of rotation of the plate and having relative dwell times which are longer as the distance from the axis of rotation increases.
Claim 12
Dependent Claim
31 words
Apparatus of claim 1, wherein the melting means comprises an electron beam-heated intermediate reservoir through which the metal melted away from the rod-shaped starting material is fed to the spinning plate.
Claim 13
Dependent Claim
23 words
Apparatus of claim 1, wherein the melting means includes means for rotating the rod-shaped starting material at low rotatory speed during the melting.
References Cited (Backward Citations)
US3275787A
Cited
US3582529A
Cited
US3721511A
Cited
US3869232A
Cited
US3829538A
Cited
US3963812A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-19 | 1985-04-20 | 1985-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-19 | 1989-04-20 | 1989-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-19 | 1993-04-20 | 1993-10-20 | $7700.00 | Window Closed / Lapsed |