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Full-Text Articles in Mechanical Engineering
On The Investigation Of Hot Tearing Behavior Of Continuous Cast Steel, Yanru Lu
On The Investigation Of Hot Tearing Behavior Of Continuous Cast Steel, Yanru Lu
Masters Theses
”Hot tearing has long been recognized as a major problem that plagues the development of the continuous casting process and results in low-quality products. Understanding of the mechanisms and the required conditions for the hot tearing formation is important for industries but has not been well-established yet. Thus, this research focuses on the hot tearing issue observed in continuous cast steel, by providing a summary of the current research progress and then introducing a new laboratory method to determine the thermo-mechanical properties relevant to hot tearing of different steel grades under different solidification conditions. In this method, an apparatus was …
In-Situ X-Ray Imaging Of The Selective Laser Melting Process, Meelap M. Coday
In-Situ X-Ray Imaging Of The Selective Laser Melting Process, Meelap M. Coday
Masters Theses
"Fusion-based metal additive manufacturing (AM) has garnered much interest in recent decades. Despite the popularity of fusion-based AM technologies such as selective laser melting (SLM), there are still fundamental questions and uncertainties that need to be addressed. In this work, we focus on the understanding of the undercooling in the SLM process and the uncertainties induced by the laser beam size, power, and scan speed. First, we report the estimation of undercooling in the SLM process from the solidification rate measured by in-situ high-speed synchrotron x-ray imaging, based on the dendrite growth velocity model. The undercooling changes as a function …
Probabilistic Simulation Of Solidification Microstructure Evolution During Laser-Based Metal Deposition, Jingwei Zhang, Frank W. Liou, William Seufzer, Joseph William Newkirk, Zhiqiang Fan, Heng Liu, Todd E. Sparks
Probabilistic Simulation Of Solidification Microstructure Evolution During Laser-Based Metal Deposition, Jingwei Zhang, Frank W. Liou, William Seufzer, Joseph William Newkirk, Zhiqiang Fan, Heng Liu, Todd E. Sparks
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A predictive model, based on a Cellular Automaton (CA) - Finite Element (FE) method, has been developed to simulate microstructure evolution during metal solidification for a laser based additive manufacturing process. The macroscopic FE calculation was designed to update the temperature field and simulate a high cooling rate. In the microscopic CA model, heterogeneous nucleation sites, preferential growth orientation and dendritic grain growth kinetics were simulated. The CA model was able to show the entrapment of neighboring cells and the relationship between undercooling and the grain growth rate. The model predicted the dendritic grain size, structure, and morphological evolution during …
Numerical Simulation Of The Evolution Of Solidification Microstructure In Laser Deposition, Zhiqiang Fan, Todd E. Sparks, Frank W. Liou, Anand Jambunathan, Yaxin Bao, Jianzhong Ruan, Joseph William Newkirk
Numerical Simulation Of The Evolution Of Solidification Microstructure In Laser Deposition, Zhiqiang Fan, Todd E. Sparks, Frank W. Liou, Anand Jambunathan, Yaxin Bao, Jianzhong Ruan, Joseph William Newkirk
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A predictive model is developed to simulate the evolution of the solidification microstructure during the laser deposition process. The microstructure model is coupled with a comprehensive macroscopic thermodynamic model. This model simulates dendritic grain structures and morphological evolution in solidification. Based on the cellular automata approach, this microstructure model takes into account the heterogeneous nucleation both within the melt pool and at the substrate/melt interface, the growth kinetics, and preferential growth directions of dendrites. Both diffusion and convection effects are included. This model enables prediction and visualization of grain structures during and after the deposition process. This model is applied …