Hans-Joachim H Lunk

US Patent:

6478845, Nov 12, 2002

Filed:

Jul 9, 2001

Appl. No.:

09/902353

Inventors:

Hans-Joachim Lunk - Towanda PA
Michael Salmen - Hiltenfingen, DE
Anna S. Nached - Sayre PA
Maria B. Winnicka - Sayre PA
Henry J. Stevens - Athens PA

Assignee:

Osram Sylvania Inc. - Danvers MA

International Classification:

B22F 924

US Classification:

75362, 75363, 75369, 419 34

Abstract:

A boron addition for making potassium-doped tungsten powder is described herein. Boron is added to a potassium-doped starting material, preferably in the form of boric acid, and then the mixture is reduced to form a potassium-doped tungsten powder. The boron addition results in increased potassium incorporation in the potassium-doped tungsten powder and also effects an increase in potassium retention in sintered compacts of the potassium-doped tungsten powder.

US Patent:

7988760, Aug 2, 2011

Filed:

Feb 25, 2008

Appl. No.:

12/036507

Inventors:

Hans-Joachim Lunk - Towanda PA, US
Henry J. Stevens - Athens PA, US

Assignee:

Global Tungsten & Powders Corp. - Towanda PA

International Classification:

B22F 9/22

US Classification:

75369, 75623

Abstract:

There is described a method of making a nanocrystalline tungsten powder that comprises: (a) heating a tungsten-containing material in a reducing atmosphere at an intermediate temperature of from about 600 C. to about 700 C. for an intermediate time period; the tungsten-containing material being selected from ammonium paratungstate, ammonium metatungstate or a tungsten oxide; and (b) increasing the temperature to a final temperature of about 800 C. to about 1000 C. for a final time period.

US Patent:

7989064, Aug 2, 2011

Filed:

Jan 9, 2006

Appl. No.:

11/306706

Inventors:

Hans-Joachim Lunk - Towanda PA, US
Ricky D. Morgan - Milan PA, US
Henry J. Stevens - Athens PA, US
Dale E. Benjamin - Athens PA, US
Tuan A. Dang - Sayre PA, US
Timothy A. Frisk - Towanda PA, US

Assignee:

Global Tungsten & Powders Corp. - Towanda PA

International Classification:

B32B 5/16

US Classification:

428403, 428404

Abstract:

The coating the tungsten powder particles with a ceramic barrier suppresses the leachability of tungsten in aqueous media. Preferably, the ceramic coating substantially encapsulates each particle of tungsten and has a thickness of at least about 30 nm and, more preferable, from about 200 nm to about 500 nm. Examples of ceramic coatings that may be used include, but are not limited to, aluminum oxide (alumina), aluminum oxyhydroxide (AlOOH), zirconium oxide (zirconia), cerium oxide (ceria), hafnium oxide (hafnia), and magnesium oxide (magnesia).

US Patent:

20060196585, Sep 7, 2006

Filed:

Jan 9, 2006

Appl. No.:

11/306705

Inventors:

Hans-Joachim Lunk - Towanda PA, US
Ricky Morgan - Milan PA, US
Henry Stevens - Athens PA, US

Assignee:

OSRAM SYLVANIA INC. - Danvers MA

International Classification:

C22B 34/30
C01G 41/00
C01G 37/14
C22C 27/04

US Classification:

148423000, 423053000, 423058000, 423061000

Abstract:

The leachability of tungsten in an aqueous medium may be suppressed by combining tungsten metal with a metal oxide or metal salt that will form an insoluble tungsten-containing compound when the mixture is brought into contact with an aqueous medium. The additive is preferably present in an amount from about 1 weight percent (wt. %) to about 10 weight percent of the tungsten of the tungsten. Preferred additives are lead oxide and calcium sulfate.

US Patent:

20060198773, Sep 7, 2006

Filed:

Jan 9, 2006

Appl. No.:

11/306704

Inventors:

Hans-Joachim Lunk - Towanda PA, US
Ricky Morgan - Milan PA, US
Henry Stevens - Athens PA, US

Assignee:

OSRAM SYLVANIA INC. - Danvers MA

International Classification:

C22B 34/30
C01G 41/00
C01G 37/14
C01G 37/00

US Classification:

423053000, 423058000, 423061000

Abstract:

The interaction of Sn, Sb and Pb with tungsten in contact with an aqueous medium has a synergistic effect in which the leachability of each metal is suppressed. This means that tungsten has the ability to suppress the leachability of these same metals, in particular lead. For example, tungsten may be added to the lead-contaminated soil in order to suppress lead contamination of the ground water by forming lead tungstate which has a very low solubility.

US Patent:

61654124, Dec 26, 2000

Filed:

Sep 7, 1999

Appl. No.:

9/390201

Inventors:

Hans-Joachim Lunk - Towanda PA
Michael Salmen - Brandenburg, DE
Henry J. Stevens - Athens PA

Assignee:

Osram Sylvania Inc. - Danvers OH

International Classification:

B22F 102

US Classification:

419 4

Abstract:

A method of making a potassium-doped tungsten powder is described comprising forming a mixture of ammonium paratungstate or ammonium metatungstate and a potassium-containing compound selected from a thermally unstable potassium-containing salt or a potassium tungstate, and reducing the mixture in a single step without adding additional dopants to form a potassium-doped tungsten powder. The potassium-doped tungsten powder produced by the method of this invention can be pressed, sintered and drawn to produce a non-sag tungsten wire.

US Patent:

57953660, Aug 18, 1998

Filed:

Feb 28, 1996

Appl. No.:

8/608552

Inventors:

Michael Salmen - Munich, DE
Hans-Joachim Lunk - Towanda PA
Alfred-Georg Gahn - Koenigsbrunn, DE
Bernhard Altmann - Langerringen, DE
Martin Fait - Berlin, DE

Assignee:

Patent-Treuhand-Gesellschaft fuer elektrische Gluehlampen mbH - Munich

International Classification:

B22F 924

US Classification:

75368

Abstract:

To essentially eliminate aluminum and silicon as contaminants in a doped tungsten wire, the tungsten wire is obtained by mechanical working of reduced tungsten blue oxide which contains as a primary or major constituent a special hexagonal ammonium tungsten bronze of the general formula (NH. sub. 4). sub. X (NH. sub. 3). sub. y WO. sub. 3. A liquid doping step is carried out by adding a solution containing potassium nitrate, the special doped ammonium tungsten bronze forming preferably more than 70% by weight of the overall tungsten blue oxide. The special hexagonal ammonium tungsten bronze is made by decomposing ammonium paratungstate in an ammonium atmosphere, preferably at a temperature between about 400. degree. and 550. degree. C.

US Patent:

57857318, Jul 28, 1998

Filed:

Feb 28, 1996

Appl. No.:

8/608550

Inventors:

Martin Fait - Berlin, DE
Joachim Fuchs - Berlin, DE
Alfred-Georg Gahn - Koenigsbrunn, DE
Hans-Joachim Lunk - Towanda PA
Michael Salmen - Munich, DE
Burkhard Ziemer - Berlin, DE

Assignee:

Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH - Munich

International Classification:

B22F 924

US Classification:

75368

Abstract:

To dope ammonium paratungstate with potassium, essentially devoid of silicon and ammonium, an aqueous potassium containing solution, preferably potassium hydroxide is added to an aqueous solution of ammonium paratungstate (APW), in a mol relationship of potassium to ammonium of between 0. 1 and 10. A doped ammonium potassium paratungstate (AKPW) is obtained. This ammonium potassium paratungstate is then converted to tungsten blue oxide, which is reduced, preferably in a hydrogen containing atmosphere and a tungsten powder is then obtained which will be doped with 40 to 120 ppm, preferably about 90 ppm of potassium. Lamps equipped with tungsten wire filaments drawn from so doped tungsten have lifetimes at least 10% more than lamps with conventional tungsten filaments.