Product Code: PIC2008_806

Three Dimensional Analytical and Finite Element Methods for Simulating a Moving Melt Pool with Mass Addition
Authors:
Andrew Pinkerton, The University of Manchester; Manchester Great Britain
Alhaji Kamara, The University of Manchester; Manchester Great Britain
Kamran Shah, The University of Manchester; Manchester M60 1Qd Great Britain
Shakeel Safdar, Pakistan National University of Sciences and Technology (Nust); Risalpur Pakistan
Lin Li, The University of Manchester; Manchester Great Britain
Presented at PICALO 2008

Laser Direct Metal Deposition, alloying and similar multiple layer additive processes are recognised as difficult to model because of the complicated mass and heat flow and numerous phase changes. There have so far been a large number of alternative approaches used to model such processes, or sections of them, but they can all be classified as either analytical or finite element in approach. This paper compares the two approaches via a case study of the coaxial laser direct metal deposition of Inconel 718. The analytical models used are based on superposition of the quasi-stationary temperature fields of multiple moving heat sources, in some cases modified to account for the incoming mass. The finite element models used are based on element birth methods, employing fixed and floating mesh techniques. The simulations are verified against experimental results obtained with a coaxial diode laser direct metal deposition system. The results show how accurately and under what conditions each of the methods accurately simulate the real process and highlight the strengths and limitations of the respective approaches.