Assoc. Prof. Dr. GÜLDEM KARTAL ŞİRELİ
Department of Metallurgical and Materials Engineering
İstanbul Technical University, TR
Dr. Güldem Kartal Şireli is an Associate Professor at Department of Metallurgical and Materials Engineering in İstanbul Technical University (I.T.U). She received her B.Sc. in Metallurgical and Materials Engineering Program of I.T.U with an honor award in 2002 and her M.Sc. and Ph.D. degrees in the same program of I.T.U in 2004 and 2012 respectively. She worked as a visiting scholar in Argonne National Laboratory, USA between 2008 and 2010. Dr. Kartal Sireli’ s research interests include: chemical and electrochemical metallurgy- molten salts systems, recovery and refining of metals; surface modification techniques- diffusion based surface hardening processes and development of green technologies. In recognition of her innovative research, she received R&D-100 Awards in process science with the design of Ultra-Fast and Large-Scale Boriding in 2012. She has acted as referee in many international journals, and taken part in many industrial projects. Dr. Kartal Sireli authored / co-authored more than 50 papers and gave several invited talks at international conferences. Her published work has received more than 650 citations. She holds 3 patents.
New Green Technology for Boron Diffusion Applications into Different Substrates
Hard and corrosion-resistant surfaces on engineering components have been increasingly requested to have longer service life along with better performance. Transition metal borides, an important class of advanced structural ceramic materials, are the perfect candidate for various applications due to their extraordinary characteristic properties; such as high melting points and extreme hardness, good wear and corrosion resistance as well as excellent thermal and electrical properties. Borides are the binary or higher solid compounds of boron and metal. Most of the borides were synthesized by Moissan in early 1900s. Despite this earlier discovery, borides haven’t found in modern technology as many as carbides or nitrides. The main reason of this less attention of borides is due to their long, costly and challenging manufacturing processes. Instead of following common long procedure, metal boride can be grown on any conductive substrates in a fast and more importantly simply as well as environmentally friendly way. With our developed coating techniques, the metal boride can be grown by diffusing boron atoms into the surface of substrate materials via CRTD-Bor (cathodic reduction and thermal diffusion boriding) or can be formed as a coating by co-reduction of both metal and boron form the electrolyte. The novel part of these techniques is to the utilization of simple oxide-based chemicals; hence many technical issues was eliminated such as the usage of expensive chemicals and the necessity of long process durations and the generation of huge amounts of solid wastes and gaseous emissions. By playing process parameters, the desired composition of boride phase is possible to be grown on any substrates such as steels including high alloy steels, nickel based alloys and titanium and its alloys, etc. This techniques is minimum 6 times faster and there is no environmental issues as experienced in conventional industrial processes.