Deakin University, Institute for Frontier Materials, Geelong, Australia
Bio: Professor Barnett is Director of the Institute for Frontier Materials and the ARC Training Centre in Alloy Innovation for Mining Efficiency at Deakin University. He has a background in metallurgical research, beginning his career in BHP Steel. He obtained his Bachelor’s degree from RMIT University in Melbourne and his PhD from McGill University. His current research is aimed at designing alloys, processes and materials that stimulate circularity of material use – materials that can be readily recycled, reused, refurbished or shared.
The impact of grain size on failure during the forming of magnesium
Abstract: The present talk examines the failure of magnesium alloy AZ31 during tension, compression and bending. The focus is on the role of the crystallographic grain size. It is well known that refining the grain size in magnesium alloys leads to higher levels of tensile ductility. The reasons for this are examined by using X-ray microtomography to characterize void nucleation, growth and linkage during tensile loading. It is shown that the impact of grain size on void growth is the critical factor. Voids grow more rapidly in coarser grained samples and this accelerates failure. It is also shown that this mechanism does not operate during compression and so in compression, the grain size has no appreciable impact on the strain to failure, all else constant. Finally, the implications of these findings on the behavior during bending is explored.
Wuhan University of Technology, Wuhan, China
Bio: Dr Lin Hua is a professor of Wuhan University of Technology, a winner of the National Science Fund for Distinguished Young Scholars of China, and the vice president of China Society for Technology of Plasticity. Professor Lin Hua has been engaged in the theory and technology research of performance products and green forming technologies for a long time. Aiming at high-performance, low-consumption and green manufacturing demand of key components in mechanical equipment, the collaborative forming theory of metal deformation and phase transformation is proposed, and the advanced forming technologies are developed, including the near-net ring rolling technology of high-performance ring, the near-net rotary forging technology for high-performance gear, the net combined fine blanking technology for high-precision and high-strength medium or heavy plate parts, which greatly improve the forming precision and performance of the products. The forming theory and technology have been applied in manufacturing the high-performance components such as mechanical bearings, petrochemical equipment, energy equipment and aero-engine, etc., which have achieved remarkable technical and economic benefits. Professor Lin Hua has published two academic books and more than 100 peer-reviews scientific papers. Besides, he hold more than 50 patents. He is also the leader of a research group which has more than 30 research scientists working in the area of metal forming theory and technology development.
Investigation on near-net ring rolling of high-performance ring: theory, technology and equipment
Abstract: Ring is the key basic component of mechanical equipment to bear load and transmit motion. Its quality directly affects the service performance and life of the equipment. Thus, the manufacturing of high-performance ring is an urgent problem to be solved in the development of high-end bearings, energy, aviation and spaceflight equipment. Near-net ring rolling is a technology can result in continuous local plastic deformation to manufacture high-performance seamless ring with accurate geometry dimension, profile-followed metal streamline and fine grain structure. This technology is an international frontier direction for high-performance ring manufacturing. In the plenary talk, recent studies on near-net ring rolling conducted by our research team in the aspects of theory, technology and equipment will be presented systematically. The ring rolling mechanism of biting into rolling cavity, plastic penetration in deformation zone, keep ring stiffness and maintain motion stability is given. The ring rolling law of macroscopic deformation and microstructure evolution is revealed. And the ring rolling theory and technical design method are established. Further, the near-net cold ring rolling technology of high carbon steel bearing ring at room temperature is developed. The heavy-load precision drive mechanism by electromechanical servo system is firstly created. And the high precision numerical control cold ring rolling mill is manufactured. The tolerance of cold rolled bearing rings is 10μm , which is the most accurate in the world. The fatigue life of bearing is increased by 1~2 times higher than that of bearing produced by conventional technologies. The near-net hot radial-axial ring rolling technology of super-large ring is also developed. The numerical control hot radial-axial ring rolling mill for super-large ring is manufactured. The outer diameter of the largest hot rolled ring is nearly16 meters, which is the largest in the world. A novel compound forming principle for traditional ring rolling and three-roll cross ring rolling is invented. The new technology and equipment of near-net combined ring rolling for special structure ring are developed. The research results have been applied in manufacturing the high-performance ring such as mechanical bearings, petrochemical equipment, energy equipment and aero-engine, etc., which have achieved remarkable technical and economic benefits. In general, the investigation promotes the development of ring rolling theory, technology and equipment.
The University of Sheffield, Department of Materials Science and Engineering, Sheffield, UK
Bio: Martin Jackson is Professor of Advanced Metals Processing at the University of Sheffield, Department of Materials Science and Engineering, UK. He has over 20 years’ experience in metals processing and in particular the solid state processing of titanium alloys, including forging, machining and powder processing. Martin’s research group – Sheffield Titanium Alloy Research (STAR) – collaborate largely with the aerospace, automotive and defence sectors, developing new processes routes and alloys that help to reduce the cost of titanium. He graduated from the University of Sheffield in 1997 and after working at Rolls-Royce he spent 10 years at the Royal School of Mines, Imperial College London before returning to the University of Sheffield in 2008 as a Royal Academy of Engineering Research Fellow. Martin is currently the Henry Royce Institute core area champion for Advanced Metals Processing and the UK representative for the World Titanium Conference which he will be chairing in 2023 in Edinburgh.
The exploitation of field assisted sintering technology (FAST) for next generation titanium alloy components
Abstract: Field assisted sintering technology (FAST) is developing into a cost effective hybrid manufacturing route to consolidate a range of metallic powder and particulate feedstocks. It has advantages over conventional sintering and hot isostatic pressing routes. In this paper he will present the work of his colleagues in the Sheffield Titanium Alloy Research (STAR) Group who are exploiting FAST to consolidate titanium powder and machining swarf. FAST can be used to produce near net shapes prior to finish machining or as a billet manufacturing step prior to hot closed die forging (termed FAST-forge). Examples of microstructural evolution compared to conventionally forged titanium product will be presented. The paper will also include examples of how the FAST process can be used to develop dissimilar titanium alloy bonds – where titanium alloy powders are poured into the FAST graphite moulds in partitioned regions and are diffusion bonded during the FAST process (a process termed FAST-DB). Structurally integral bonds with chemically graded microstructures are developed in a controlled manner and it will be demonstrated how FE, multi-physics and thermodynamic modelling software can be used to predict the evolution of such bond alloy gradients during processing. Finally, I will show some of the mechanical properties that can be achieved and the response of such material to machining.
Konstantin V. Redkin
Corporate Research Metallurgist, Mechanical Engineer, PhD, at the WHEMCO Inc., Pittsburgh, PA, USA
Bio: Dr Redkin works as Corporate Research Metallurgist, Mechanical Engineer, PhD, at the WHEMCO Inc. group companies in Pittsburgh, PA, USA. He also holds a position of Visiting Researcher at Ferrous Physical Metallurgy Laboratory, Mechanical Engineering and Materials Science Department, Swanson School of Engineering at The University of Pittsburgh. He is a Vice Chair of Metallurgy- Processing, Products & Applications Technology Committee in the Association for Iron and Steel Technology (AIST).
New Challenges and Advances in Rolling Mill Rolls Design and Applications
Abstract: The talk will address state-of-the-art rolling mill rolls used in metal forming primarily for hot and cold rolling. Complex roll engineering approaches will be demonstrated via the “product life-cycle management” concept, touching base on the fundamentals of solidification and solid-state transformation during manufacturing, addressing degradation competing mechanisms that rolls’ material is exposed to. The most recent challenges in the steel industry to produce Advance High Strength Steels (AHSS) by rolling wider and lighter gages present challenges to the roll manufacturer. Increased rolling mill loads and intensified rolling campaigns impose challenges on the roll materials subjected to highly aggressive high temperature environments and complex tribology. Transient dynamic cyclical loading requires improved damage tolerance and increased fatigue endurance of rolls used for flat rolling. Continuously evolving rolling parameters driven by material developments impose limitations on obsolete rolls materials and quality levels. In order to address modern challenges breakthrough multi-scale multiphysical techniques in materials simulation, characterization and testing were developed. Spatial and path dependent material properties in large roll sections were studied through computational simulation. Models were validated via mechanical testing and advanced electron microscopy characterization. Proposed techniques and methods of the study will be summarized for wide spectrum of steels and highly alloyed irons, revealing the same governing natural phenomena. Developed approaches can be applied to different classes of alloys and applications.