Product Code: ICAL08_511

A Time-dependent Multiphysics Simulation of Laser Solid Freeform Fabrication Process for Heterogeneous Structures
Authors:
Ehsan Toyserkani, University of Waterloo; Waterloo ON Canada
Masoud Alimardani, University of Waterloo; Waterloo ON Canada
Jan P. Huissoon, University of Waterloo; Waterloo ON Canada
Presented at ICALEO 2008

In new advanced emerging technologies, heterogeneous components with multi-material structures are required in order to enhance their mechanical properties for functioning in a multidisciplinary environment. Laser solid freeform fabrication (LSFF) inherently has great potential for fabrication of these kinds of structures. This paper presents a coupled 3D transient numerical approach for modeling multilayer LSFF of heterogeneous structures. Using this model, temperature distribution and stress field are dynamically obtained throughout the process domain assuming the interaction between the laser beam and the powder stream is decoupled. Once the melt pool boundary is obtained, the geometry of the multilayer deposited materials can be predicted based on the powder feed rate, elapsed time, and intersection between the melt pool and powder stream area. The main process parameters affected by the deposition on non-planar surfaces, such as powder catchment efficiency, are incorporated into the model. The proposed algorithm is used to simulate the fabrication of a heterogeneous structure with a cylindrical shape. The effects of the multi-material depositions (e.g., Ti and Co) on the temperature and stress distribution patterns are investigated. Numerical results are experimentally verified by their experimental counterparts using a 1 kW fiber laser coupled with a 7 axis workstation.