**5. Data collection**

The information obtained from FEA study and validation study can be used in order to design and develop a spatio-temporal neural network. This artificial

intelligence algorithm can provide optimized process parameters to produce parts with minimum defects. The experimental procedure being costly and designed to be at the end of the project, we started with initial FEA study at CFD level. We have created a Design of Experiment (DOE) study using CFD analysis. We have used two different material powder, three different laser power setting and three different scanning speed settings to perform the DOE. Moreover, we are considering single pass single layer melting only. The main purpose of this DOE is to investigate the diverse data obtainable from the simulations and understand impact of process parameter on the temperature map on PBF processes. So, there are 2 x 3 x 3 = 18 cases in design of experiments using full factorial method. **Table 1** shows the DOE setup.

In addition to the defined input variables for the case study, i.e., material type, laser power and speed, many other parameters are also needed to setup the CFD simulation in *FLOW-3D AM***®**. The simulation setup is quite critical as the melting process itself is very complex. Basic setup steps are described here. Interested readers can visit here to obtain more in-depth knowledge and tutorials to use for individual studies.

	- Pressure = 1.0e6 dyne/cm<sup>2</sup> ,
	- Heat transfer co-efficient =1.0e5 erg/cm<sup>2</sup> /s/K
	- Gamma = 1.4.


#### **Table 1.**

*DOE case setup for CFD simulations.*

*Multiscale Modeling Framework for Defect Generation in Metal Powder Bed Fusion Process… DOI: http://dx.doi.org/10.5772/intechopen.104493*


**Figure 10.** *Laser progression and temperature profile map (a) to (f) shows progression in time domain.* 0.8 cm, radius of 0.01 mm and spot radius of 0.003 cm. Only X directional velocities are used, they are zero in Y and Z directions.

• Materials are used only Inconel-718 and PH-316 Stainless Steel in this case study, and the built-in property directory is utilized as well. In specific studies, we can also edit any relevant properties of material as needed.
