Solutions for Experimental Verification of Melt Pool Modeling for Additive Manufacturing

Conference Abstract: Using simulation for process and material development in additive manufacturing is important yet challenging due to the complex physics of metal solidification. To trust the results and subsequent analysis of a model, it must first undergo scrutiny against results obtained by either experiments or analytical solutions. In additive manufacturing, simulation results are typically compared with etched cross-sections from a built part or coupon. That way, the depth and width of a melted track can be compared against simulation results side-by-side. However, this comparison leaves out critical details such as melt pool temperature field and transient keyhole dynamics as well as track shape during printing. In-situ technology such as x-ray imaging and temperature measurements are key to fully validating melt pool models so that researchers can fully exploit the information from the simulation.

In this presentation we will look at techniques AM researchers have used to validate melt pool models using the computational fluid dynamics software FLOW-3D AM. We will discuss case studies using various approaches with ex-situ and in-situ technology. We will discuss how the insights gained from process dynamics that lead to defects such as porosity and cracking can also be used to validate against experiments. Finally, we will discuss how data from multi physics simulations can be fed into microstructure models. These crystal growth models can further extend the validation effort by providing grain solution that can be compared to electron backscattered diffraction (EBSD) images of the built part or coupon.