Dr. Marios Demetriou

Education:

Ph.D. in Mechanical Engineering, University of California, Los Angeles, 2001
Dissertation: Kinetic Simulation of Thermally Induced Metastability in the Tungsten-Carbon System.
Advisors: Professors N. M. Ghoniem, and A. S. Lavine

MS in Mechanical Engineering, University of California, Los Angeles, 1997
Thesis: Thermal Aspects of Grinding: Simulation of the Up-Grinding Problem.
Advisor: Professor A. S. Lavine

BS in Mechanical Engineering, University of Arizona, 1995, GPA: 3.96
Senior Design Project: Design and Development of an Integrated Solar Collector.

Research Interests:

Non-equilibrium thermal processing of advanced materials, including metastable and glassy (amorphous) materials.

Experience:

2002 - present, Subcontracted Consultant at Liquidmetal Technologies
Assessment, simulation, and optimization of melt flow behavior in casting of metallic glass components.
2001 - present, Post-Doctoral Scholar at California Institute of Technology
Simulation and experimental investigation of thermal flow and phase evolution in casting of bulk metallic glasses.
Supervisor: Mettler Professor W. L. Johnson; Sponsors: D.A.R.P.A.
Fall 2001, Guest Instructor at University of California, Los Angeles
Lecturing of MA105D - Transport Phenomena (49 students).
1996 - 2001, Research Assistant IV at University of California, Los Angeles
Modeling of non-equilibrium kinetic phenomena such as crystal nucleation and growth; transport phenomena such as heat conduction, convection and radiation; and thermodynamic phenomena such as melting, evaporation and boiling. Experimental investigation in the areas of plasma spray coating and thermo-mechanics of fusion reactor blankets.
1996 - 2001, Teaching Fellow at University of California, Los Angeles
Assisted in lecturing of the courses of Intermediate Heat Transfer (7 qt), Elementary Thermodynamics (5 qt), Elementary Fluid Mechanics (1 qt), Transport Phenomena (1 qt), and Thermo-Chemical Processing of Materials (1/2 qt), by lecturing the recitation session, holding office hours, preparing and grading exams, and assigning homework.
Summer 1999, Subcontracted Consultant at Powdermet, Inc.
Extensive literature investigation towards developing a patent-oriented defense strategy in coated-particle industry.

Honors & Awards:

Outstanding Ph.D. Award in Mechanical Engineering, University of California, Los Angeles, 2002
Industrial Fellowship, IMM, University of California, San Diego, 1996-1999.
Departmental Fellowship, MAE, University of California, Los Angeles, 1995-1996.
International Student Scholarship, University of Arizona, 1994-1995.
Summa Cum Laude, University of Arizona, 1995
Phi Kappa Phi, Certificate of Highest Scholastic Achievement, University of Arizona, class of 1995

:Research Activity:

Thermal flow evolution of bulk metallic glasses
The flow evolution of glass forming liquids in casting is simulated by means of finite element modeling. The model incorporates the viscosity dependence on shear rate and temperature hence it accounts for non-Newtonian flow effects such as shear thinning, shear localization, and shear banding. The model is calibrated experimentally and is intended to optimize the industrial processing of structural amorphous solids.
Crystallization kinetics during non-equilibrium processing of tungsten carbide
A stochastic computational model is developed to dynamically simulate the nucleation-controlled kinetics in the W-C system upon superheating and supercooling at 50%-C, which corresponds to the composition of WC peritectic phase. Upon superheating, the model suggests that under highly non-equilibrium conditions the graphite phase, which evolves via peritectic melting, may be kinetically bypassed giving rise to metastable congruent melting of WC. Upon supercooling, the model suggests that under highly non-equilibrium conditions W2C and WC1-x become more kinetically favored than the thermodynamically stable WC, in accordance with experimental observations.
Feasibility of plasma spray process in developing MMC coatings
The in-flight heating, melting, and evaporation of metal-coated ceramic powder particles injected in a non-steady arc-jet DC plasma was simulated. The suitability of plasma spraying in developing particulate-reinforced metal-matrix composite coatings was assessed.
Simulation of the up-grinding process
A thermal model is developed for the up-grinding mode, which couples the thermal behavior of the workpiece, grains, fluid, and chips, and computes the workpiece temperature rise. The results are in agreement with experimental data.

Publications::
Referred Journals:
Demetriou, M. D., and Johnson, W. L., 2002, Mater. Sci. Eng. A, In Press
Johnson, W. L., Lu, J., Demetriou, M. D., 2002, Intermetallics, In Press
Demetriou, M. D., Ghoniem, N. M., and Lavine, A. S., 2002, J. Chem. Phys., In Press
Demetriou, M. D., Ghoniem, N. M., and Lavine, A. S., 2002, Acta Mater., In Press
Demetriou, M. D., Ghoniem, N. M., and Lavine, A. S., 2002, J. Phase Equilib., Vol. 23, pp. 305-309.
Demetriou, M. D., Ghoniem, N. M., and Lavine, A. S., 2002, Acta Mater., Vol. 50, pp 1421-1432.
Demetriou, M. D., Lavine, A. S., and Ghoniem, N. M., 2002, J. Manuf. Sci. and Eng., Vol. 124, No. 1, pp. 58-64.
Demetriou, M. D., and Lavine, A. S., 2000, J. Manuf. Sci. and Eng., Vol. 120, No. 4, pp. 605-611.
Conference Proceedings:
Demetriou, M. D., Lavine, A. S., and Ghoniem, N. M., Sep. 1999, Proc. of the ISAPS ’99 Advances in Applied Plasma Science, Vol. 2, pp. 431-438.
Demetriou, M. D., Lavine, A. S., and Ghoniem, N. M., Mar. 1999, Proc. of the 5th ASME/JSME Joint Thermal Engineering Conference, Paper No. AJTE99/6158.
Demetriou, M. D., and Lavine, A. S., Aug. 1997, Proc. of the ASME National Heat Transfer Conference, Vol. 9, HTD-Vol. 347, pp. 251-259.
Demetriou, M. D., Lavine, A. S., and Ghoniem, N. M., Sep. 1997, Proc. of the ISAPS ’97 Advances in Applied Plasma Science, Vol. 1, pp. 75-82.
Contributing Editor
Ghoniem, N. M., and Walgraef, D., Instabilities in Materials, to be published in 2001 by Kluwer, the Netherlands.

Contact Information:

California Institute of Technology
Department of Materials Science
Mail Stop 138-78
Pasadena, CA 91125
(626) 395-4425
marios@caltech.edu

Dr. Marios Demetriou

	Education: Ph.D. in Mechanical Engineering, University of California, Los Angeles, 2001 Dissertation: Kinetic Simulation of Thermally Induced Metastability in the Tungsten-Carbon System. Advisors: Professors N. M. Ghoniem, and A. S. Lavine MS in Mechanical Engineering, University of California, Los Angeles, 1997 Thesis: Thermal Aspects of Grinding: Simulation of the Up-Grinding Problem. Advisor: Professor A. S. Lavine BS in Mechanical Engineering, University of Arizona, 1995, GPA: 3.96 Senior Design Project: Design and Development of an Integrated Solar Collector. Research Interests: Non-equilibrium thermal processing of advanced materials, including metastable and glassy (amorphous) materials. Experience: 2002 - present, Subcontracted Consultant at Liquidmetal Technologies Assessment, simulation, and optimization of melt flow behavior in casting of metallic glass components. 2001 - present, Post-Doctoral Scholar at California Institute of Technology Simulation and experimental investigation of thermal flow and phase evolution in casting of bulk metallic glasses. Supervisor: Mettler Professor W. L. Johnson; Sponsors: D.A.R.P.A. Fall 2001, Guest Instructor at University of California, Los Angeles Lecturing of MA105D - Transport Phenomena (49 students). 1996 - 2001, Research Assistant IV at University of California, Los Angeles Modeling of non-equilibrium kinetic phenomena such as crystal nucleation and growth; transport phenomena such as heat conduction, convection and radiation; and thermodynamic phenomena such as melting, evaporation and boiling. Experimental investigation in the areas of plasma spray coating and thermo-mechanics of fusion reactor blankets. 1996 - 2001, Teaching Fellow at University of California, Los Angeles Assisted in lecturing of the courses of Intermediate Heat Transfer (7 qt), Elementary Thermodynamics (5 qt), Elementary Fluid Mechanics (1 qt), Transport Phenomena (1 qt), and Thermo-Chemical Processing of Materials (1/2 qt), by lecturing the recitation session, holding office hours, preparing and grading exams, and assigning homework. Summer 1999, Subcontracted Consultant at Powdermet, Inc. Extensive literature investigation towards developing a patent-oriented defense strategy in coated-particle industry. Honors & Awards: Outstanding Ph.D. Award in Mechanical Engineering, University of California, Los Angeles, 2002 Industrial Fellowship, IMM, University of California, San Diego, 1996-1999. Departmental Fellowship, MAE, University of California, Los Angeles, 1995-1996. International Student Scholarship, University of Arizona, 1994-1995. Summa Cum Laude, University of Arizona, 1995 Phi Kappa Phi, Certificate of Highest Scholastic Achievement, University of Arizona, class of 1995 :Research Activity: Thermal flow evolution of bulk metallic glasses The flow evolution of glass forming liquids in casting is simulated by means of finite element modeling. The model incorporates the viscosity dependence on shear rate and temperature hence it accounts for non-Newtonian flow effects such as shear thinning, shear localization, and shear banding. The model is calibrated experimentally and is intended to optimize the industrial processing of structural amorphous solids. Crystallization kinetics during non-equilibrium processing of tungsten carbide A stochastic computational model is developed to dynamically simulate the nucleation-controlled kinetics in the W-C system upon superheating and supercooling at 50%-C, which corresponds to the composition of WC peritectic phase. Upon superheating, the model suggests that under highly non-equilibrium conditions the graphite phase, which evolves via peritectic melting, may be kinetically bypassed giving rise to metastable congruent melting of WC. Upon supercooling, the model suggests that under highly non-equilibrium conditions W2C and WC1-x become more kinetically favored than the thermodynamically stable WC, in accordance with experimental observations. Feasibility of plasma spray process in developing MMC coatings The in-flight heating, melting, and evaporation of metal-coated ceramic powder particles injected in a non-steady arc-jet DC plasma was simulated. The suitability of plasma spraying in developing particulate-reinforced metal-matrix composite coatings was assessed. Simulation of the up-grinding process A thermal model is developed for the up-grinding mode, which couples the thermal behavior of the workpiece, grains, fluid, and chips, and computes the workpiece temperature rise. The results are in agreement with experimental data. Publications:: Referred Journals: Demetriou, M. D., and Johnson, W. L., 2002, Mater. Sci. Eng. A, In Press Johnson, W. L., Lu, J., Demetriou, M. D., 2002, Intermetallics, In Press Demetriou, M. D., Ghoniem, N. M., and Lavine, A. S., 2002, J. Chem. Phys., In Press Demetriou, M. D., Ghoniem, N. M., and Lavine, A. S., 2002, Acta Mater., In Press Demetriou, M. D., Ghoniem, N. M., and Lavine, A. S., 2002, J. Phase Equilib., Vol. 23, pp. 305-309. Demetriou, M. D., Ghoniem, N. M., and Lavine, A. S., 2002, Acta Mater., Vol. 50, pp 1421-1432. Demetriou, M. D., Lavine, A. S., and Ghoniem, N. M., 2002, J. Manuf. Sci. and Eng., Vol. 124, No. 1, pp. 58-64. Demetriou, M. D., and Lavine, A. S., 2000, J. Manuf. Sci. and Eng., Vol. 120, No. 4, pp. 605-611. Conference Proceedings: Demetriou, M. D., Lavine, A. S., and Ghoniem, N. M., Sep. 1999, Proc. of the ISAPS ’99 Advances in Applied Plasma Science, Vol. 2, pp. 431-438. Demetriou, M. D., Lavine, A. S., and Ghoniem, N. M., Mar. 1999, Proc. of the 5th ASME/JSME Joint Thermal Engineering Conference, Paper No. AJTE99/6158. Demetriou, M. D., and Lavine, A. S., Aug. 1997, Proc. of the ASME National Heat Transfer Conference, Vol. 9, HTD-Vol. 347, pp. 251-259. Demetriou, M. D., Lavine, A. S., and Ghoniem, N. M., Sep. 1997, Proc. of the ISAPS ’97 Advances in Applied Plasma Science, Vol. 1, pp. 75-82. Contributing Editor Ghoniem, N. M., and Walgraef, D., Instabilities in Materials, to be published in 2001 by Kluwer, the Netherlands. Contact Information: California Institute of Technology Department of Materials Science Mail Stop 138-78 Pasadena, CA 91125 (626) 395-4425 marios@caltech.edu
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