Prof. Sergei Alexandrov, Beihang University, China
Institute for Problems in Mechanics, Russian Academy of Sciences, Moscow, Russia
Sergei Alexandrov is a Professor at Beihang University (under the 1000 Talent Plan program) and a Research Professor at the Laboratory for the Mechanics of Technological Processes at A. Ishlinskii Institute for Problems in Mechanics of the Russian Academy of Sciences. He received his Ph.D. in Physics and Mathematics in 1990 and D.Sc. in Physics and Mathematics in 1994. He worked as a Professor at Moscow Aviation Technology Technical University (Russia), a Visiting Scientist at ALCOA Technical Center (USA), GKSS Research Centre (Germany) and Seoul National University (South Korea), and was a Visiting Professor at Aveiro University (Portugal), University of Besancon (France) and Technical University of Malaysia (Malaysia). He is a member of the Russian National Committee on Theoretical and Applied Mechanics. Sergei Alexandrov has published more than 350 papers in journals, books and conference proceedings, including two monographs and around 190 papers in journals indexed in the Web of Science. He has participated in the scientific committee of several international conferences and served as a reviewer in a wide range of international journals. He is on the editorial board of several journals including Continuum Mechanics and Thermodynamics (Springer) and Structural Engineering and Mechanics (Technopress). His research areas are plasticity theory, fracture mechanics, and their applications to metal forming and structural mechanics.
Speech Title: Planar and Axisymmetric Ideal Flows in Pressure – Dependent Plasticity
Abstract: Ideal flows have been defined elsewhere as solenoidal smooth deformations in which an eigenvector field associated everywhere with the greatest principal strain rate is fixed in the material. Under such conditions all material elements undergo paths of minimum plastic work, a condition which is advantageous for metal forming processes. The ideal flow theory has been used as the basis of a procedure for the preliminary design of such processes. In particular, the distribution of strain and material properties is uniform in the final product of steady processes. The ideal flow theory has been long associated with the Tresca yield criterion and its associated flow rule. The objective of the present paper is to extend this theory to the double shearing model that is widely adopted in pressure – dependent plasticity. Both steady and nonsteady plane strain and axisymmetric processes are considered. An efficient numerical approach for design of metal forming processes is developed. ..
Prof. Yuyuan Zhao, University of Liverpool, UK
Professor Yuyuan Zhao obtained his BEng and MSc degrees from Dalian University of Technology, and PhD degree from Oxford University. He worked as a Lecturer at Dalian University of Technology, a Research Associate at the MADYLAM Laboratory of CNRS, and a Research Fellow at Birmingham University, before he joined Liverpool University in 1998 as a Lecturer. He was subsequently promoted to Senior Lecturer, Reader and then Professor, and served as Head of the Centre for Materials and Structures from 2014 to 2016.
He is currently professor in materials engineering in the School of Engineering, the University of Liverpool. He is a Chartered Engineer (CEng) and a Fellow of the Institute of Materials, Minerals and Mining (FIMMM). Professor Zhao's current research is focused on the manufacture, characterisation and applications of porous metals and metal matrix syntactic foams.
He pioneered the Sintering and Dissolution Process (SDP) for manufacturing aluminium foam, which inspired the subsequent developments of several powder-based space-holder methods for manufacturing metal foams. He further invented the Lost Carbonate Sintering (LCS) process, a more versatile and cost-effective method for producing micro-porous metals. The LCS technology has led to the creation of Versarien, a highly successful start-up company which was floated on London Stock Market in 2013.
Professor Zhao was awarded the Ivor Jenkins Medal in 2015 by the Institute of Materials, Minerals and Mining for his contribution to powder metallurgy in developing and commercialising innovative powder based technologies for manufacturing metal foams.
Speech Title: Metal Foams Manufactured by P/M Based Space Holder Methods
Abstract: Space-holder methods are a family of processes for manufacturing porous metals utilising filler materials to create pores. In solid route space holder methods, the metal matrices are formed by powder metallurgy. This presentation gives a short overview of the recent developments on the manufacturing processes, the porous structure and the characteristic properties of the as manufactured porous metals.
In powder metallurgy based space holder methods, a metal powder is first mixed with a filler material in the powder form. The mixture is then compacted and subsequently sintered to form a metal network. The filler material is removed either before, or during, or after the sintering to generate the pores in the resultant porous metal. Two mechanisms can be used to remove the filler material: dissolution and decomposition.
Porous metals produced by the space holder methods have distinctive porous structures. In effect, the pores are negative replicas of the particles of the filler material and the porosity is determined by the volume fraction of the filler material in the powder mixture preform. Pore shape, pore size and porosity can all be controlled accurately.
The functionality of the porous metals derives from the combinations of distinctive characteristics of the solid and gaseous phases. The solid phases provide geometrical architecture, strength, electrical conductivity, thermal conductivity, magnetic shielding, acoustic barrier etc. The gaseous phase offers compressibility and allows fluids to flow through. Examples of applications include impact energy absorbers, heat exchangers, sound absorbers and porous electrodes.
Dr.LYDIA ANGGRAINI, Head, Study Program of Mechanical Engineering, President University, Indonesia
Lydia Anggraini received her M.Eng and Ph.D degree from Ritsumeikan University, Japan in 2008 and 2012, respectively. She studied Advanced Materials Science and Engineering in the Department of Mechanical Engineering, Ritsumeikan University. She joined Indonesia EPSON Industry Co., Ltd. in 2005. Since 2010, she has been a Research Assistant in the Advanced Materials Laboratory, Department of Mechanical Engineering, Ritsumeikan University, Japan. In 2013, she joined the Faculty of Engineering, President University, Jababeka, Cikarang, Indonesia where she is currently a Head of Study Program of Mechanical Engineering in President University. She is now engaged in research on microstructure control to create high mechanical properties of metal-matrix and ceramics-matrix composites, and its applications. She is now leading a research project under Collaborative Research Based on Industrial Demand "Electric Vehicle Development for Green City". 2017
Speech Title: Microstructure and Mechanical Properties of Copper-Iron Fabricated by Mechanical Milling and Continuous Sintering
Abstract: This research is to analyze the effect of mechanical milling on the microstructure and mechanical properties of copper-iron. The sample is fabricated by compacting, milling and sintering processes. Sintering process is carried out using continuous type machine with conveyor belt mesh and the furnace type is muffle. After that, it is cooled with natural water jacket process. Vicker hardness testing and tensile strength test is performed to determine the mechanical properties of copper-iron alloys that occur. The mean value of sample 1 hardness (before milling) was 39.8 HV. The mean value of sample hardness 2 (after milling) was 74.9 HV. The value of the yield strength (σ) of sample 1 is 17.597MPa, and the value of ductility (ε) is 0.119. The value of the yield strength (σ) of sample 2 is 18.547 MPa, and the value of ductility (ε) is 0.073. The test results and analysis showed that by shrinking the size of metal powder, by milling for 2 hours, the hardness and yield strength of the product can increase. Although, the product becomes more brittle which is indicated by the decreased ductility value.