Physics-based Modeling of Microstructural Alteration in Metal Cutting and Machinability Improvement via Laser-Assisted Machining
MIE Department Seminar
November 10, 2015
11:00 AM - 12:00 PM
Physics-based Modeling of Microstructural Alteration in Metal Cutting and Machinability Improvement via Laser-Assisted Machining
Hongtao Ding, PhD.
Department on Mechanical & Industrial Engineering, University of Iowa
Abstract: Materials often behave in a complicated manner involving deeply coupled effects among stress/stain, temperature, and microstructure during a machining process. The first part of this talk is concerned with physics-based modeling of microstructural alterations during metal cutting. A dislocation density- based numerical framework is developed to simulate grain refinement due to severe plastic deformation. A coupled metallo-thermo-mechanical analysis is performed to investigate the surface microstructure alteration, particularly the white layer formation mechanisms incorporating both the thermally driven phase transformation and mechanical grain refinement due to severe plastic deformation. Through a quantitative assessment using the experimental data, the model simulations demonstrate the essential characteristics of the deformation field and microstructural evolution mechanisms during metal cutting.
The second part of this talk discusses the recent advancements of laser-assisted machining (LAM) for difficult-to-machine materials. One-step laser-assisted machining process is studied for hardened steels to replace hard turning and grinding operations. A 3D heat transfer model is developed to predict the temperature field inside the workpiece of complex geometry undergoing laser-assisted profile turning. Microstructure of 4130 steel workpiece is simulated by considering both phase transformation kinetics and grain refinement. The surface integrity analysis is experimentally studied by changing heating and operating conditions, viz., average material removal temperature, cutting speed and feed.
Bio: Hongtao Ding is an assistant professor in Mechanical and Industrial Engineering at the University of Iowa. Ding received his bachelor’s degree from Shanghai Jiao Tong University, China, master’s degree from the University of Michigan and doctorate from Purdue University, all in mechanical engineering. His primary research focus is laser-based material processing and machining, with specialization in surface microstructural control. Particular topics of interest include: laser-assisted machining of ceramics and difficult-to-machine alloys, laser deposition joining of fiber reinforced polymer composites, hybrid machining, laser peening, laser hardening and laser patterning. Ding haspublished over 20 refereed technical articles in archival journals. Ding received the ASME “Best Paper Award” at the 2011 Manufacturing Science and Engineering Conference, and the SME “Outstanding Young Manufacturing Engineer Award” in 2015.
Date posted
Oct 14, 2021
Date updated
Oct 14, 2021