报告题目：Integrated modelling of the laser metal deposition (LMD) process for 3D printing of critical components with alloy powders
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 overall integrated LMD 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 quid/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.