چهارمین سخنران کلیدی همایش
1396-09-14
چهارمین سخنران کلیدی همایش

Bio-sketch

Dr. Javad Mostaghimi is the Distinguished Professor in Plasma Engineering in the Department of Mechanical & Industrial Engineering at the University of Toronto and the director of Centre for Advanced Coating Technologies (CACT). He received a BSc degree from Sharif University, Iran, in 1974, and MSc and PhD degrees in Mechanical Engineering from the University of Minnesota, Minneapolis, in 1978 and 1982, respectively. Before joining University of Toronto in 1990, he held positions at Pratt & Whitney Canada, Longueil, Quebec, and the Department of Chemical Engineering, University of Sherbrooke, Sherbrooke, Quebec.

His main research interests are the study of thermal spray coatings, transport phenomena and electromagnetics in thermal plasma sources; in particular, study of the flow, temperature, and electromagnetic fields within arcs and RF inductively coupled plasmas. Professor Mostaghimi has done extensive simulation of the dynamics of droplet impact and solidification in thermal spray processes and automotive spray painting.

Professor Mostaghimi is a fellow of the following professional societies: Royal Society of Canada, ASME, ASM, CSME, EIC, CAE, AAAS, and IUPAC. He is a recipient of: the 75th Anniversary Medal of the ASME Heat Transfer Division, Robert W. Angus Medal of the CSME, Heat Transfer Memorial Award of the ASME, Jules Stachiewicz Medal of the CSME, NSERC Brockhouse Canada Prize and the Engineering Medal in R & D from the Professional Engineers of Ontario.

He is a member of the editorial board of Plasma Chemistry and Plasma Processing and a member of the International Review Board of the Journal of Thermal Spray.

 

 

 

 

Topic of speech: A Novel Fabrication Process of Depositing Super-hydrophobic Ceramic Coatings by Solution Precursor Plasma Spray (SPPS)

 

Abstract

A novel fabrication process of depositing super-hydrophobic ceramic coatings by solution precursor plasma spray (SPPS) without using any low-surface-energy modifiers is presented. Ytterbium nitrate solution is used as feedstock and injected into a DC plasma jet to deposit ytterbium oxide ceramic coatings. The coating formation process from liquid solution precursors to solid ceramics is discussed and details of the process, including the interaction of the injected solution into the high temperature plasma are presented. The microstructures of coated surfaces are characterized which show a dual-scale hierarchical columnar structures composed of micron-sized clusters with nano-sized splats/particles on the top. The formation mechanism of columnar structures and microstructure variation of coatings along standoff distances are investigated. The micron-sized clusters and nano-sized splats/particles on the top of clusters formed hierarchical structures which rendered the coating super-hydrophobic.

The wetting behavior of the coatings were characterized by the static water contact angle measurement, water droplet roll-off test and dynamic water impact test on the coated surfaces. The contact angle of water droplet on the best quality coatings were about 163, and the roll-off angle was about 6o with complete droplet bounce-off properties. The various wetting behavior of coatings at different standoff distances are explained by correlating it with the coating microstructures and surface topographies. Self-cleaning test was applied and showed the excellent hydrophobicity of the coatings.