TIEN-CHIEN JEN(任天健)
ASME Fellow
Professor, Mechanical Engineering Science
University of Johannesburg, South Africa
Tel: US: 414-336-0378
South Africa: +27 11 5594208
Email:tienchienjen@gmail.com
tjen@uj.ca.za
Google Scholar:https://scholar.google.co.za/citations?hl=en&user=Q-vedboAAAAJ
Abstract
The Cold Gas Dynamics Spraying (CGDS) deposition process is an emerging technology for coating surfaces and consolidation of powder. The process is based on the impact on and the subsequent adherence to a substrate of particles of high kinetic energy. Current CGDS involves injecting microscopic powdered particles of a metal or another solid into a supersonic jet of rapidly expanding gas and then shooting them at a target surface. The process is performed in order to directly bond powder with the substrate through high-speed impact.In contrast to well-known thermal spray processes, the cold spray particles (metals, polymers) never become melted throughout the whole process. Low deposition temperatures offer several advantages over other thermal spraying and plasma spray particles techniques, including no phase transformations, little or no oxidation, no evaporation, no substrate melting and no recrystallization. In addition, the residual stresses and deformation induced by the mismatch between the thermal expansion coefficients of the coating and the substrate are minimized. Furthermore, the process is inherently safer than thermal spray methods because there are no molten materials. The CGDS coating process requires less capital investment and less space than conventional thermal spray methods. The powders (fall off from the substrate) can even be recycled to improve the economics of the process.
Biography
Education
Jan. 1988 – March 1993 Ph.D., Mechanical and Aerospace Engineering, University of California, Los Angeles
Sept. 1985 – June 1987 M.S., Power Mechanical Engineering, National Tsing-Hua University, Hsinchu, Taiwan
Sept. 1978 – June 1982 B.S., Naval Architecture and Marine Engineering, National Cheng-Kung University, Tainan, Taiwan
Positions Held
July 2015 – present Professor, Department of Mechanical Engineering Science, University of Johannesburg, South Africa
August 2013 – June 2015 Adjunct Professor, University of Wisconsin, Milwaukee
May 2013 – May 2014 Dean, College of Engineering, UAA
Oct. 2010 – Sep 2012 Interim Dean, College of Engineering and Applied Science, UWM
July 2008 – May 2013 Professor, University of Wisconsin, Milwaukee
July 2005 – June 2010 Chairman, Mechanical Engineering Department
Aug. 2001 – June 2008 Associate Professor, University of Wisconsin, Milwaukee
Aug. 1997 – July 2001 Assistant Professor, University of Wisconsin, Milwaukee
Aug. 1996 – Aug. 1997 Visiting Assistant Professor, Oakland University,Rochester, Michigan
Apr. 1993 – July 1996 Assistant Research Engineer, General Motors and Mechanical and Aerospace Engineering, University of California, Los Angeles
Jan. 1988 – March 1993 Research Assistant, University of California, Los Angeles
Sept. 1985 – June 1987 Research Assistant, National Tsing-Hua University,Hsin-chu, Taiwan
Publications
Professor Jen has written a total of 173 peer-reviewed papers including 80 peer-reviewed journal papers, published in many prestigious journals includingInternational Journal of Heat and Mass Transfer, ASME Journal of Heat Transfer, ASME Journal of Mechanical DesignandASME Journal of Manufacturing Science and Engineering.He also has written five chapter papers including a chapter inNumerical Simulation Proton Exchange Membrane Fuel Cell,published by WIT Press, and another chapter inApplication of Lattice Boltzmann Method in Fluid Flow and Heat Transfer in Computational Fluid Dynamics – Technology and Application, and more.
Patents
Professor Jen has applied for two Chinese patents (2013104728193 and 2013104728371 ), and other two inventions that have been revealed TTO (Technology Transfer Office, University of Johannesburg) are pending (2015).
Special Honors and Awards
Elected to the status ofAmerican Society of Mechanical Engineer Fellowin recognizing the contribution to Mechanical Engineering, October 2011
Appointed asGuest Professor of Chongqing University, China,in recognition of significant research achievement, October 2009
Appointed asGuest Professor of Anhui Agriculture University, China,in recognition of significant research achievement, October 2009
Appointed asGuest Professor of Shangdong University, China,in recognition of significant research achievement, October 2010
CEAS Million Dollars Research Funding Club,in recognition of significant funding received, September 2008
Graduate School/UWM Foundation Outstanding Research Award,in recognition of Outstanding and Creative Activity, November 2000
NSF GOALI Award, the first award of its kind ever awarded to UWM by NSF, 1999 – 2006
Outstanding Research Award, CEAS, UWM, 2001
SME Research Initiation Award, SME Education Foundation, 1998 – 1999
SME Research Initiation Award, SME Education Foundation, 1997 – 1998
Best Paper Award, CIRP Annals, titled “Thermal Aspects of Grinding with CBN Wheels,”CIRP Annals, Vol. 38, No. 1, pp.557 – 560
Listed inMarquis Who’s Who in Science and Engineering(1994 – to date)
Listed inMarquis Who’s Who in the World(1994 – to date)
Listed inMarquis Who’s Who in America(1995 – to date)
Listed inLexington Who’s Who(1999 – to date)