HEEMAN CHOE

E.O. Lawrence Berkeley National Laboratory
University of California at Berkeley
1 Cyclotron Rd., MS 62-203
Berkeley, CA 94720
Phone: (510)486-5515
Fax: (510)486-4995
hchoe@lbl.gov

EDUCATION

University of California at Berkeley
Ph.D. in Materials Science expected Fall, 2001 (GPA: 3.91/4.0)
(Minors in Math & Composite materials)

University of California at Irvine
M.S. in Materials Science and Engineering, June, 1997
KAIST (Korea Advanced Institute of Science and Technology)
B.S. in Materials Science and Engineering, Feb., 1995

EMPLOYMENT EXPERIENCE

Dept. of Materials Science and Mineral Engineering, University of California at Berkeley
Research Assistant for Professor R. O. Ritchie, Ph.D., Sc.D.
(Aug. 1997 – present)

Small crack behavior of in-situ toughened SiC and mechanical properties of intermetallics (gamma TiAl and Mo-12Si-8.5B) both at room temperature and high temperature

University of California at Irvine
Research Assistant, Dept. of Materials Science and Mineral Engineering
(Aug. 1995 – June 1997)
Daewoo corporation, Korea
Summer Intern, Powder metallurgy processing and development of advanced magnetic materials
(May 1994 – Aug. 1994)

TEACHING EXPERIENCE

Teaching Assistant for E45: "The structure and properties of materials", Professor Morris, Spring 2000. 2-3 times a week of 3-hour lab session included.

PROJECTS

Basic automation system using fluid dynamics (3/93 - 6/93)

Enhancement of high temperature properties of verious MoSi₂ composites (9/95 - 3/96)

Thermal expansion coefficient of Si₃N₄ composites (3/96 - 5/97)

Thermal conductivity measurement of various materials with Hughes (12/96 - 2/97)

Small crack measurement of in-situ toughened ABC-SiC (2/98 - 9/99)

Investigation on new generation gamma TiAl (7/98 - 4/99)

Mechanical properties of a boron-doped multiphase intermetallic, Mo-12Si-8.5B both at room and high temperatures (4/99 - Present)

Investigation on oxidation resistance and mechanical properties of Mo-16.8Si-8.4B using "materials-by-design concept" (8/00 - Present)

SKILLS

Experienced in metallography, image analysis, optical microscopy, scanning and transmission electron microscopy, x-ray diffraction and spectroscopy, and mechanical testing of materials (MTS and Instron control formats)

AWARDS

University of California at Berkeley, University Fellowship, Fall 1999

University of California at Irvine, University Fellowship, 1995 - 1997

PUBLICATIONS

H. Choe, D. Chen, J.H. Schneibel, and R.O. Ritchie, "Ambient to High Temperature Fracture Toughness and Fatigue-Crack Propagation Behavior in a Mo-12Si-8.5B (at.%) Intermetallic," accepted to be in Intermetallics, 2001.
H. Choe, D. Chen, J.H. Schneibel, and R.O. Ritchie, "Fracture and Fatigue-Crack Growth Behavior in a Mo-12Si-8.5B Intermetallic at Ambient and Elevated Temperatures," in Fatigue and fracture behavior of high temperature materials, P.K. Liaw, eds., TMS, Warrendale, PA, pp. 17-24, 2000.
H. Choe, T. Hsieh, Y. Wu, E.J. Lavernia, and J. Wolfenstine, "The Effect of Powder Processing on the Mechanical Behavior of MoSi₂ - Si₃N₄ Composites," Journal of Materials Synthesis and Processing, 4(4), pp. 235-243, 1996.
H. Choe, T. Hsieh, and J. Wolfenstine, "The Effect of Powder Processing on the Coefficient of Thermal Expansion of MoSi₂ - Si₃N₄ Composites," Materials Science and Engineering, 237(2), pp. 250-255, 1997.
J.J. Kruzic, J.P. Campbell, A.L. Mckelvey, H. Choe, and R.O. Ritchie, "The Contrasting Role of Microstructure in Influencing Fracture- and Fatigue-Crack Growth in Gamma-Based Titanium Aluminides at Large and Small Crack Size," in Gamma Titanium Aluminides 1999, Y-W. Kim, D.M. Dimiduk, and M. H. Loretto, eds., TMS, Warrendale, PA, 1999.
T. Hsieh, H. Choe, E.J. Lavernia, and J. Wolfenstine, "Thermal Expansion Behavior of MoSi₂ - Si₃N₄ Composites," Materials Letters, 30(5-6), pp. 407-410, 1997.
T. Hsieh, H. Choe, Y. Wu, E.J. Lavernia, and J. Wolfenstine, "Processing and Properties of MoSi₂ - Si₃N₄ Composites," in Processing and fabrication of advanced materials V, T.S. Srivatsan and J.J. Moore, eds., TMS, Warrendale, PA, pp. 337-346, 1996.

CONFERENCE PRESENTATIONS

H. Choe, T. Hsieh, and J. Wolfenstine, "The Effect of Powder Processing on the Coefficient of Thermal Expansion of MoSi₂ - Si₃N₄ Composites," presented at the conference on Mechanical Properties of Interfacial Materials, Kona, HI, Jan. 1996.