AM_09a: Grid Calculation for an SS316L Alloy

This example shows the use of the AM Calculator with a Steady-state mode and Grid Calculation Type where it compares the calculated and measured printability map. Printability maps are also known as process maps. The experiments are from Hu et. al [2019Hu] where they performed single track experiments with the alloy SS316L at different power and scan speeds.

The use of different Plot types in this example include a Printability map and a 3D plot with surface colormap.

This example is part of a set using a Steady-state simulation with a Gaussian heat source, plus the Keyhole model including Fluid flow. These examples collectively show the use of Batch and Grid calculation types plus various plot types such as Printability maps, Parity plots, and Melt pool vs energy density. The examples are numbered AM_07 to AM_09b.

  • Folder: Additive Manufacturing
  • File name: AM_09a_Printability_Map_316L.tcu

This example requires an Additive Manufacturing (AM) Module license.

Configuration and Calculation Set Up

Below highlights some of the settings for this example. This example builds on the previous ones (AM_07, AM_08a, and AM_08b) and it is recommended to review these and to open the example file to locate and follow along for the settings described here and found on the Configuration window.

The Steady-state calculation is configured with the Gaussian Heat Source with the Keyhole model and includes Fluid flow.

The Gaussian Beam radius is set to 22 μm. The Absorptivity is set to 30 % and in the Scanning Strategy section, the powder Layer thickness is set to 10 μm.

The SS316L material is selected from the Material Properties library. The material properties are precalculated and stored as a built-in material Library.

The Grid Calculation Type is used to cover all the conditions from the experiments in a single calculation. The Power ranges between 40‑100 W and the Scanning speed ranges between 400‑3000 mm/s.

Visualizations

Open the example project file to review the node setup on the Project window and the associated settings on the Configuration window for each node. For some types of projects, you can also adjust settings on the Plot Renderer Configuration window to preview results before performing the simulation. Click Perform Tree to generate plots and tables to see the results on the Visualizations window.

When you run (Perform) this example, it can take around two hours to complete the calculations.

There is a wide variety of information shown both in the Visualizations and Plot Renderer Configuration windows that can be viewed during configuration and after performing the calculation(s). Not all views, such as the Geometry or previews, nor all additional output (i.e. plots) are shown in this section and it is recommended that you open and run the example to review all available options and results.

Plot Renderer Configuration Window

The combined results from the Grid calculation can be viewed under the matching Grid tab on the Plot Renderer Configuration window where it is configured to use the Printability map plot type. In this example, the Plot Renderer node is renamed to Printability map in the Project window.

The combined results from the Grid calculation can be viewed under the matching Grid tab on the Plot Renderer Configuration window where it is configured to use the Printability map plot type.

Next each Function is defined and limits were adjusted to match the experimental regions of keyholing and lack of fusion porosity.

  • The keyholing limit (Keyholing: Wk/Dk) is kept at default 1.0.
  • The Lack of fusion: D/t is increased from default of 1.0 to 1.3.
  • The experiments were only single-track and the lack of fusion at half of the hatch distance (Lack of fusion hatch: Dh/t) is kept at default 1.0 and only included together with the Hatch distance of 35 μm for demonstration purposes.

The settings for the printability map with the Function limits defined for keyholing, lack of fusion, and lack of fusion at half of the hatch distance

Figure 1: The settings for the printability map with the Function limits defined for keyholing, lack of fusion, and lack of fusion at half of the hatch distance (as described in the text).

Printability Map and 3D Plot

There is a video tutorial about the Printability Map on our website and on our YouTube channel. It is also included in the Additive Manufacturing Module YouTube playlist.

The calculated printability map for SS316L showing the regions for keyholing porosity (upper left) and lack of fusion porosity to the lower right.

Figure 2: Printability map for 316L showing regions of keyholing and lack-of-fusion. Experimental information from Hu et. al. [2019Hu] overlaid as coloured labels showing keyhole porosity (K), conduction mode with lack-of-fusion porosity (C). Green labels showing experiments without defects for conduction mode (C) and keyhole mode (K).

3D plot showing a keyhole for the simulation that uses power 100 W and scan speed 400 mm/s.

Figure 3: 3D plot showing a keyhole for the simulation that uses power 100 W and scan speed 400 mm/s.

Reference

[2019Hu] Z. Hu, B. Nagarajan, X. Song, R. Huang, W. Zhai, J. Wei, Formation of SS316L Single Tracks in Micro Selective Laser Melting: Surface, Geometry, and Defects. Adv. Mater. Sci. Eng. 2019, 1–9 (2019).

Other Resources

Read more about the Additive Manufacturing (AM) Module on our website including the details about database compatibility or to watch an introductory webinar. You can also use the Getting Started Guide to learn about the key features available.