Choong Whan Kim

US Patent:

6709536, Mar 23, 2004

Filed:

Apr 2, 2002

Appl. No.:

09/890480

Inventors:

Choong Paul Kim - Northridge CA
Charles C. Hays - Pasadena CA
William L. Johnson - Pasadena CA

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

C22C 4500

US Classification:

148561, 148403, 420423

Abstract:

A composite metal object comprises ductile crystalline metal particles in an amorphous metal matrix. An alloy is heated above its liquidus temperature. Upon cooling from the high temperature melt, the alloy chemically partitions, forming dendrites in the melt. Upon cooling the remaining liquid below the glass transition temperature it freezes to the amorphous state, producing a two-phase microstructure containing crystalline particles in an amorphous metal matrix. The ductile metal particles have a size in the range of from 0. 1 to 15 micrometers and spacing in the range of from 0. 1 to 20 micrometers. Preferably, the particle size is in the range of from 0. 5 to 8 micrometers and spacing is in the range of from 1 to 10 micrometers. The volume proportion of particles is in the range of from 5 to 50% and preferably 15 to 35%. Differential cooling can produce oriented dendrites of ductile metal phase in an amorphous matrix.

US Patent:

7244321, Jul 17, 2007

Filed:

Dec 12, 2003

Appl. No.:

10/735148

Inventors:

Choong Paul Kim - Northridge CA, US
Charles C. Hays - Pasadena CA, US
William L. Johnson - Pasadena CA, US

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

C22C 45/00

US Classification:

148561, 148421

Abstract:

A composite metal object comprises ductile crystalline metal particles in an amorphous metal matrix. An alloy is heated above its liquidus temperature. Upon cooling from the high temperature melt, the alloy chemically partitions, forming dendrites in the melt. Upon cooling the remaining liquid below the glass transition temperature it freezes to the amorphous state, producing a two-phase microstructure containing crystalline particles in an amorphous metal matrix. The ductile metal particles have a size in the range of from 0. 1 to 15 micrometers and spacing in the range of from 0. 1 to 20 micrometers. Preferably, the particle size is in the range of from 0. 5 to 8 micrometers and spacing is in the range of from 1 to 10 micrometers. The volume proportion of particles is in the range of from 5 to 50% and preferably 15 to 35%. Differential cooling can produce oriented dendrites of ductile metal phase in an amorphous matrix.

US Patent:

8613813, Dec 24, 2013

Filed:

Mar 23, 2009

Appl. No.:

12/409253

Inventors:

William L. Johnson - Pasadena CA, US
Marios D. Demetriou - Los Angeles CA, US
Choong Paul Kim - Glendale CA, US
Joseph P. Schramm - Pasadena CA, US

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

C22F 1/10
B23K 15/00

US Classification:

148561, 21912111, 219773, 723421

Abstract:

An apparatus and method of uniformly heating, rheologically softening, and thermoplastically forming metallic glasses rapidly into a net shape using a rapid capacitor discharge forming (RCDF) tool are provided. The RCDF method utilizes the discharge of electrical energy stored in a capacitor to uniformly and rapidly heat a sample or charge of metallic glass alloy to a predetermined “process temperature” between the glass transition temperature of the amorphous material and the equilibrium melting point of the alloy in a time scale of several milliseconds or less. Once the sample is uniformly heated such that the entire sample block has a sufficiently low process viscosity it may be shaped into high quality amorphous bulk articles via any number of techniques including, for example, injection molding, dynamic forging, stamp forging, and blow molding in a time frame of less than 1 second.

US Patent:

20060137272, Jun 29, 2006

Filed:

Dec 23, 2005

Appl. No.:

11/318160

Inventors:

Choong Kim - Rancho Palos Verdes CA, US

International Classification:

E04B 5/00

US Classification:

052411000

Abstract:

A waterproof sheet structure for a cool roof includes a waterproof sheet layer and a top reinforce layer placed on one side of the waterproof layer. The top reinforce layer is impregnated in a liquid polymer and then dried, and is treated to have a light color. The liquid polymer has fire retardant property. The top reinforce layer is made of a fiberglass cloth, which includes a plurality of glass fibers woven with one another. The polymer fill gaps between the woven fibers. The polymer is impregnated onto the fiberglass cloth in such a thickness so that there are no glass fibers exposed out of the polymer. The waterproof sheet is made by forming the fiberglass cloth, and then coating asphalt on the fiberglass cloth with a constant thickness.

US Patent:

20060174546, Aug 10, 2006

Filed:

Sep 7, 2005

Appl. No.:

11/220477

Inventors:

Choong Kim - Rancho Palos Verdes CA, US

International Classification:

E04H 15/18

US Classification:

052063000

Abstract:

A joint sealing structure for waterproof sheets for a cool roof includes a first waterproof sheet and a second waterproof sheet installed in such a manner that their edges are spaced apart from each other with a predetermined gap in-between and a polymer-filled portion that fills the gap. The polymer-filled portion is formed by filling the gap with a liquid polymer that has fire-retardant property. The waterproof sheet includes a waterproof sheet layer and a top reinforce layer placed on one side of the waterproof layer. The top reinforce layer is impregnated in the liquid polymer and then dried, and is treated to have a light color. The top reinforce layer is a fiberglass cloth having a plurality of glass fibers woven with one another. The polymer is impregnated onto the fiberglass cloth in such a thickness so that there are no glass fibers exposed out of the polymer.

US Patent:

20140033787, Feb 6, 2014

Filed:

Oct 3, 2013

Appl. No.:

14/045667

Inventors:

Marios D. Demetriou - West Hollywood CA, US
Choong Paul Kim - Glendale CA, US
Joseph P. Schramm - Sierra Madre CA, US

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

C21D 1/40
H05B 3/00
B21J 9/08

US Classification:

7234296, 219113

Abstract:

An apparatus and method of uniformly heating, rheologically softening, and thermoplastically farming metallic glasses rapidly into a net shape using a rapid capacitor discharge forming (RCDF) tool are provided. The RCDF method utilizes the discharge of electrical energy stored in a capacitor to uniformly and rapidly heat a sample or charge of metallic glass alloy to a predetermined “process temperature” between the glass transition temperature of the amorphous material and the equilibrium melting point of the alloy in a time scale of several milliseconds or less. Once the sample is uniformly heated such that the entire sample block has a sufficiently low process viscosity it may be shaped into high quality amorphous bulk articles via any number of techniques including, for example, injection molding, dynamic forging, stamp forging, and blow molding in a time frame of less than 1 second.

US Patent:

20160298205, Oct 13, 2016

Filed:

Apr 8, 2016

Appl. No.:

15/094740

Inventors:

- Pasadena CA, US
Marios D. Demetriou - West Hollywood CA, US
Choong Paul Kim - Glendale CA, US
Joseph P. Schramm - Sierra Madre CA, US

International Classification:

C21D 7/13
C22F 1/14
C21D 1/38
C22C 45/00
C22C 45/02
C22F 1/18
C22C 45/10

Abstract:

An apparatus and method of uniformly heating, rheologically softening, and thermoplastically forming metallic glasses rapidly into a net shape using a rapid capacitor discharge forming (RCDF) tool are provided. The RCDF method utilizes the discharge of electrical energy stored in a capacitor to uniformly and rapidly heat a sample or charge of metallic glass alloy to a predetermined “process temperature” between the glass transition temperature of the amorphous material and the equilibrium melting point of the alloy in a time scale of several milliseconds or less. Once the sample is uniformly heated such that the entire sample block has a sufficiently low process viscosity it may be shaped into high quality amorphous bulk articles via any number of techniques including, for example, injection molding, dynamic forging, stamp forging, and blow molding in a time frame of Less than 1 second.