百年机械，名家论坛-10月13日英国思克莱德大学罗熙淳教授学术报告
报告题目：Hybrid micromachining - a paradigm shift in micromanufacturing
时间：10月13日上午9:00
地点：威廉希尔316
报告人：罗熙淳教授（英国思克莱德大学）
报告人简介：Xichun Luois a Professor in ultra precision manufacturing and technical director of Centre for Precision Manufacturing (CPM) at the University of Strathclyde (Glasgow). He is a Fellow of the International Society for Nanomanufacturing and an editor for Proceeding of IMechE Part C: Journal of Mechanical Engineering Science, Journal of Micromanufacturing, Advances in Mechanical Engineering and Mechanical Sciences. He also sits in the editorial board for Micromachines, Nanomanufacturing and Metrology. He obtained his PhD in ultra precision manufacturing at Harbin Institute of Technology (China) and second PhD in Precision Engineering at Leeds Metropolitan University (UK). From 2004 to 2007, he worked at Cranfield University as a research officer to develop freeform diamond turning/ grinding process and machines. From 2007 to 2012 he was a lecturer at Heriot-Watt University and established Nanomanufacturing Laboratory. From 2012 to 2013 he was a Reader in ultra precision manufacturing at the University of Huddersfield where he leads an Advanced Machining Research Group. His research has been founded by the EPSRC, EC, Royal Society and Industry. His research interests include ultra precision machining brittle materials, freeform machining, precision motion control, hybrid micromachining and FIB nanomanufacturing, as evidenced bytwo books and more than 100 papers in peer-reviewed highly ranked journals. He chaired two IEEE International Conferences in Automation and Computing in 2014 and 2015. He won UKInstitution of Mechanical Engineers (IMechE) 2015Ludwig Mond Prize for his work in the application of digital technology in micro- and nano-manufacturing.
报告内容：Micromanufacturing has attracted great attention as micro-components/products such as micro-displays, micro-sensors, micro-batteries, etc. are becoming established in all major areas of our daily life and can already been found across the broad spectrum of application areas especially in sectors such as automotive, aerospace, photonics, renewable energy and medical instruments. These micro-components/products are usually made of multi-materials (may include hard-to-machine materials) and possess complex shaped micro-structures but demand sub-micron machining accuracy. A number of micro-machining processes is therefore, needed to deliver such components/products.
The talk introduces the concept of hybrid micro-machining process which involves integration of various micro-machining processes with the purpose of improving machinability, geometrical accuracy, tool life, surface integrity, machining rate and reducing the process forces. It uses three typical hybrid micromachining processes to demonstrate the effectiveness of hybrid micromachining process in terms of machining performance and productivity. Development a new 6-axis hybrid micro machine tool and material handling system to implement the hybrid micromachining processes is also introduced. The talk concludes with the future research focus and challenges of hybrid micromachining in the new era of smart manufacturing.
10月13日英国思克莱德大学曾泉人研究员学术报告
报告题目：Integrated modelling of the laser metal deposition (LMD) process for 3D printing of critical components with alloy powders
时间：10月13日上午10:30
地点：威廉希尔316
报告人：曾泉人研究员（英国思克莱德大学）
报告人简介：Dr Quanren Zeng is currently a Research Associate from the Department of Design, Manufacture and Engineering Management (DMEM), University of Strathclyde, UK. He received his BS, MS and PhD degree in Mechanical Engineering from the Northwestern Polytechnical University(China) in 2004, 2007 and 2012 respectively, and also a PhD degree in DMEM, University of Strathclyde (UK) in 2015. His research interest is in the broad area relating to advanced manufacturing, with a focus on additive manufacturing for metal advanced aerospace-used alloy powders, precision engineering & surface integrity for difficult-to-machine materials. Apart from 1 book chapter and 1 book translation, Dr Zeng has also published over 30 journal or conference papers in the mechanical and manufacturing field, including IJMS, J of Eng. Manu., ASS, etc. He is also a reviewer for international journals, e.g. Additive Manufacturing, Journal of Manufacturing Review, Advance in Mechanical Engineering, Optics & Laser Technology, Industrial Lubrication and Tribology, International Journal of Lightweight Materials and Manufacture. He recently received Advance Forming Research Centre “Route to Impact” funding and StrathWide2019 Seed funding for investigating the numerical modelling of additive manufacturing process for deposition of metal powders for different applications in aerospace and medical devices.
报告内容：Additive manufacturing (AM), which has completely different materials incremental manufacturing philosophy of fabricating components layer by layer via consolidation of melted powders or wire feedstock, offers a flexible and convenient means to manufacture complex structural components for hard materials. Laser metal deposition (LMD), based on a kind of directed energy deposition (DED), is one of the popular AM technologies for complex metal structural component production. It could deposit geometrically-intricate and fully-densed component directly from its CAD files without using dies, tooling or machining, which greatly reduce the lead-time and production cost.But the LMD process is complicated with a variety of factors; accurate numerical modelling of LMD process is a challenge due to the involvement of multiple physical processes as well as accompanied mass and heat flows. The consistence and reliability of the deposited components’ quality during the practical production is also not always well maintained yet; trails and errors method will be an expensive and time-consuming way to find the optimal parameter sets to fabricate quality components.
In this presentation, the overallintegratedLMD numerical modelling consideration will be introduced in details. Temperature field distributions caused by the moving laser beam and the resultant molten pool on the substrate are analysed. The gas/liquid/solid interfacial behaviours and subsequent solidification near the molten pool are simulated and compared with the experimentally-deposited tracks/layers.The proposed integrated numerical model and corresponding experiment could help give an insight of the relevant physics of the LMD process and finally facilitate the realization of high quality deposited components with better consistency by using optimized processing parameter sets. The research will be particularly useful for production of the geometrically-complex and functionally-reliable components that with higher demanding requirement in the field of aerospace, high-performance automotive and medical devices.
