AM Calculator Conditions Settings

Pressure is used to calculate the heat loss due to evaporation from the top surface of the given material.

Gas pressure: The pressure of the gas inside the build chamber. The default is 100000 Pascal. Select Atmospheres or Bar.

When you select a different unit the default value does not change.

Enter a different value in the field.

Temperature unit: Select a unit Kelvin, Celsius, or Fahrenheit.

The Ambient temperature is used to calculate the heat loss from the top surface due to radiation, convection, and evaporation.

This setting is the temperature of the air in the immediate surrounding environment.

If you change the Temperature unit then double check that the value in this field is also updated or correct as expected if you are keeping the default. This field does not update automatically when the unit changes.

Also see the theory section, Fluid Flow and if also using the keyhole model, see About the Keyhole Model.

Choose to use Fluid flow including Marangoni effect if you want to calculate and include for the effect of fluid flow due to gradient of surface tension in the melt pool. The checkbox is selected by default. This solves the Navier-Stokes equation to include fluid flow inside the melt pool due to the Marangoni effect.

If you want to use separate properties for the powder layer, click to clear the checkbox to enable Use separate material properties for powder fields and then continue with the settings below.

Height: Enter the build height (mm). Length and width of the computational domain is automatically chosen as a function of the heat source parameters and the scanning speed.

• Height: Enter the initial build height (mm). Powder layer(s) with the given layer thickness will be added on the top. In mm.
• Width: Enter the build width (along y direction). In mm.
• Length: Enter the build length (along x direction). In mm.

Mesh: The initial mesh size —Coarse, Medium, Fine, or Custom. It is adaptive and refined as required.

If Custom is selected, enter the maximum and minimum element sizes:

• Maximum element size: The initial element size (in μm) in the mesh.
• Minimum element size: The minimum element size (in μm) that the adaptive mesh can refine to.

Enter a Scanning speed, which is the velocity of the moving heat source. The default is 500 mm/s.

Enter a Layer thickness, which is the thickness of the powder layer. The default is 40 mm. When you change the layer thickness, the meshing size changes too.

Select the scanning Pattern—Single track, Bidirectional, or Unidirectional.

• Select Unidirectional to use same scanning direction of the heat source for all tracks.
• Select Bidirectional to flip scanning direction of the heat source between alternate tracks.

Single Track

• Margin: Offset of the laser scanning path from the sides of the computational domain. In case of Single track, offset is placed from the sides transverse to the scanning direction, whereas the scanning path is always in the middle of the domain going along the length of the workpiece.
• Number of layers: Enter the number of layers or scroll using the arrows.
• Powder fill time: Powder recoating time (unit = s) between two consecutive layers. This does not include lift time. This field is available when more than 1 is entered in the Number of layers field.
• Cooling time: Enter a cooling time (unit = s) This is the time for which the material is left to cool down after the scanning is completed. During cooling time, the heat source is completely turned off.

Bidirectional and Unidirectional

• Margin: Offset of the laser scanning path from the sides of the computational domain.
• Hatch spacing: Separation (unit = mm) between two consecutive tracks. 
• Lift time: Time (unit = s) between two tracks where the heat source is inactive.
• Number of layers: Enter the number of layers or scroll using the arrows.
• Powder fill time: Powder recoating time (unit = s) between two consecutive layers. This does not include lift time.
• Rotation between layers: Rotation (unit = degrees) of the scanning direction between two consecutive layers. The scanning pattern of the first layer is always aligned to the X axis then the second layer will be rotated (if you choose this setting) with the specified angle then the next layer will be rotated at the same angle as compared to the previous layer and so on. This way you can change the rotation of the layers.
• Cooling time: Enter a cooling time (unit = s) This is the time for which the material is left to cool down after the scanning is completed. During cooling time, the heat source is completely turned off.

Enter a Radiation emissivity to include the effect of radiation from the top surface to the surrounding gas. Enter a value between 0 and 1. If you want to neglect the heat loss, then enter 0 to disable radiation.

Enter a Convective heat transfer coefficient for the top surface to the surrounding gas. If you want to ignore this then enter 0 to disable convective heat transfer. The default is 20 W/m².

Select the Evaporation checkbox to include the effect of evaporation heat loss due to heating of the powder layer or the metallic surface close to the evaporation temperature.

The Evaporation heat loss is calculated based on the settings on the Materials Properties tab, i.e. evaporation enthalpy per mole, the driving force for evaporation per mole quantity and the molar mass of gas. These are also calculated by the databases.

By default for Steady-state calculations, Single point is selected, which by default uses the Gaussian Heat Source. In addition to settings described in this topic, you can also find more details in AM Calculator Heat Source Settings. This is available with all heat sources.

For some background, see About Heat Source Calibration. Also see Visualizing Heat Source Calibrations for various options related to visualizing the calibration settings.

Select Heat Source Calibration to calibrate a heat source based on the imported or entered experimental data instead of performing a single point calculation. All types of heat sources can be used. See below for additional information to enter the Experiment Data. This is available with Gaussian, Double ellipsoidal, or Conical heat sources.

Select Batch to include power and scan speed data, which is read from a file such as a spreadsheet and entered or imported to the Batch Experiment Data table. You can optionally include experimental melt pool width and depth (if there is data), and compare this to the calculated results using a Parity plot on the Plot Renderer.

This is available with all heat sources.

In addition to settings described in this topic, you can also find more details in AM Calculator Heat Source Settings and Visualizing Batch Calculations in the AM Module.

It is important to prepare the experiment data file correctly so the simulation performs smoothly. See AM Calculator Experiment File Requirements.

This section is available when Batch is selected as the Calculation Type.

In the Experiment file field, either enter a file path or click the file button () to navigate to a data file such as an Excel spreadsheet (with *.xls or *.xlsx extensions) or a *.csv file. You can also use other programs (e.g. Google Sheets) to enter data and export to a CSV format that can be read by the software.

Click Open to import the data. In the Experiment file field you can see the file path to the selected file. The next time you click the file button () the program remembers the last location from where the file is opened.

Choose the delimiter—Comma (,), Colon (:), Equals sign (=), Semicolon (;), or Tab—that matches the delimiter in the experiment file and click the Reload () button.

Select Grid to evaluate two axis variables of power and scanning speeds in the specified range and number of steps. Then continue with the Grid Definitions. In addition to settings described in this topic, you can also find more details in AM Calculator Heat Source Settings.

This is available with all heat sources.

For the Grid calculation type, define the two axes variables using the fields and menus: Quantity, Min, Max, and Number of steps. The number of steps along with the minimum and maximum values for the axes define a grid. For each grid point the selected models are evaluated.

Enter a Min, Max, and Number of steps for:

• Power (W) for the selected Heat Source model.
• Scanning speed (mm/s) for the velocity of the moving heat source.

When you also have licenses either for the Diffusion Module (DICTRA) and/or the Precipitation Module (TC-PRISMA), for transient simulations you can additionally include probe data from the AM Calculator in the set up of the thermal profile for diffusion and precipitation calculations, respectively.