Abstract
An improved mass addition approach based on enthalpy balance is used for the numerical simulation of the temperature distributions and geometries during laser rapid manufacturing (LRM) of a multi-layered thin-wall. The approach involves the estimation of the local track height at every node along the track width on the substrate/previously deposited layer by simultaneous balancing of the excessive enthalpies above solidus temperature about the laser axis and the material interface at the substrate/previously deposited layer for material addition during the laser rapid manufacturing of a multi-layer thin wall. It takes laser power, laser beam size, scan-speed, powder feed rate, powder stream diameter, and time-delay between the deposition of two subsequent tracks as user-defined input, and computes the temperature distributions and the geometries of the deposited layers across the process domain in a dynamic fashion. In the present study, the laser rapid manufacturing of five layered thin walls of SS 304L on a work piece of the same material was simulated for various combinations of processing parameters and compared with experimental results. The percentage errors in simulated and corresponding experimental cumulative track heights along with track width were calculated and compared with those of other existing models and the results of present approach were found to be the least. The result indicates that the height and width of the layer under deposition depends on the geometry and temperature distribution of previously deposited layer and, consequently, governed the final geometry of thin wall.
Acknowledgments
The authors wish to acknowledge the skillful technical support extended by Mr. S. K. Mishra and Mr. C. H. Prem Singh for experimental verification of the modeling results.
Notes
Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/unht.