Amarnath P Divecha

7090893, Aug 15, 2006

Mar 24, 2003

10/394233

Amarnath P. Divecha - Falls Church VA, US
Appajosula Srinivasa Rao - Bethesda MD, US
William A. Ferrando - Arlington VA, US

The United States of America as represented by the Secretary of the Navy - Washington DC

B05D 3/02

4273761, 4273762, 427404, 4274191, 427378

A method of forming a rhenium layer on a substrate, comprising:.

6129134, Oct 10, 2000

Mar 11, 1999

9/266266

Amarnath P. Divecha - Falls Church VA

The United States of America as represented by the Secretary of the Navy - Washington DC

B22D 1914
B22D 2700

164 97

Reinforcing particles within a flux are dispersed through a metal matrix osited into a crucible purged of air by infeed of argon gas during heating of the matrix to a melted state for completing particle dispersion by agitation before remelting thereof after solidification. The remelted matrix with the particles fully dispersed therein is then allowed to undergo sedimentation increasing particle concentration along a flat surface portion of the final product having increased wear resistance thereat.

52537978, Oct 19, 1993

Jul 21, 1992

7/916428

William A. Ferrando - Arlington VA
Subhash D. Karmarkar - Great Falls VA
Scott M. Hoover - Burtonsville MD
Amarnath P. Divecha - Falls Church VA

The United States of America as represented by the Secretary of the Navy - Washington DC

B23K 3102

228194

A thin layer of silver metal is formed between a molybdenum surface and a eel surface. The silver metal layer is diffusion bonded to the molybdenum surface and diffusion bonded to the steel surface, thus bonding the molybdenum and steel surfaces together.

45698864, Feb 11, 1986

Jun 18, 1984

6/621966

Amarnath P. Divecha - Falls Church VA
Roger E. Wilson - Silver Spring MD

The United States of America as represented by the Secretary of the Navy - Washington DC

B32B 1500
D02G 300
B05D 700
B05D 302

428379

The method of coating ceramic whiskers selected from the group consisting SiC, graphite, boron carbide and alumina with magnesium by sublimation and finally by magnesium oxide (MgO) after oxidation comprising (a) heating powdered Mg and SiC. sub. w mixture in an oxygen free atmosphere to a temperature of 400. degree. C. to 550. degree. C. (b) igniting the mixture in air in the presence of O. sub. 2 (which may incidently cause the mixture to attain a temperature more than 1800. degree. C. ) that the desired end results in a coating of MgO on the whisker or particle surfaces, to obtain novel coated whiskers varying in length from 10-100 microns.

55094597, Apr 23, 1996

Sep 28, 1994

8/313955

Amarnath P. Divecha - Falls Church VA
Subhash D. Karmarkar - Great Falls VA
Scott M. Hoover - Burtonsville MD
James M. Kerr - Bethesda MD
William A. Ferrando - Arlington VA

The United States of America as represented by the Secretary of the Navy - Washington DC

B22D 1900

164 98

A process for forming pressure cast alumina tile reinforced aluminum alloy rmor in which a silver coated aluminum disc is first inserted into a mold assembly, the mold assembly includes a base plate, a hollow steel die with a removable steel liner located on the base plate, a plug disposed on the base plate within the die cavity, and a punch movably disposed within the die cavity, the aluminum disc being inserted within the die cavity over the plug. Next, an alumina tile preform is prepared by cutting a plurality of alumina tiles and weaving the tiles together with a stiff steel wire. The alumina tile preform is inserted over the silver coated aluminum disc in the cavity of mold assembly. The steel die, the plug and the disc are heated. The punch is also heated separately.

61291358, Oct 10, 2000

Jun 29, 1999

9/342207

Amarnath P. Divecha - Falls Church VA
Subhash D. Karmarkar - Great Falls VA
William A. May - Boulder CO
James M. Kerr - Ashburn VA
William A. Ferrando - Arlington VA
Scott M. Hoover - Burtonsville MD

The United States of America as represented by the Secretary of the Navy - Washington DC

B22D 1914
B22D 2700

164 97

A predetermined quantity of a metal-matrix composite material is injected to a heating crucible along an angular infeed direction toward a location therein at which a vortex is formed by the blade of an agitator through which the material is stirred while being superheated above the melting temperature to a pouring temperature under which the melted material is transferred to a casting mold after surface skimming thereof to form a product having improved wear resistance properties.

51205750, Jun 9, 1992

May 10, 1991

7/700375

William A. Ferrando - Arlington VA
Amarnath P. Divecha - Falls Church VA
James Kerr - Bethesda MD

The United States of America as represented by the Secretary of the Navy - Washington DC

B05D 302

427229

A reaction vessel comprising (1) a porous ceramic structure having intercecting, open pores and (2) silver metal coating the inner ceramic surfaces of the reaction vessel and filling the interconnecting, open pores to form a strong bond between the porous ceramic structure and the silver coating. The reaction vessel can be produced by (1) coating the inner surface and infiltrating the continuous, open pores of an unglazed porous ceramic structure (or vessel) with molten AgNO. sub. 3 ; (2) decomposing the AgNO. sub. 3 to silver metal; and then (3) repeating steps (1) and (2) until all the pores are filled with silver metal.

49780549, Dec 18, 1990

Jul 3, 1990

7/548331

William A. Ferrando - Arlington VA
Amarnath P. Divecha - Falls Church VA
Subhash D. Karmarkar - Great Falls VA

The United States of America as represented by the Secretary of the Navy - Washington DC

B23K 120
B23K 2000
B23K10102
B23K10316

228194

A method of forming diffusion bonds between aluminum and aluminum alloy saces by coating the surfaces with molten AgNO. sub. 3 and then decomposing the AgNO. sub. 3 to form a thin uniform layer of silver on the surfaces before forming the diffusion bond. The AgNO. sub. 3 coating and decomposition in treatment permanently breaks up the Al. sub. 2 O. sub. 3 coatings on the aluminum or aluminum alloy surfaces, making diffusion bonding possible.