High Pressure Process

Define the parameters for a high pressure die casting process.

Location: High Pressure is an option on the Basic Setup icon on the Casting ribbon.

High pressure die casting uses a machine to inject molten metal into permanent metal dies under high pressure. It is a good technique for manufacturing complex parts with a high degree of accuracy, particularly lightweight parts with thin walls that require consistent dimensions. The high pressure is needed to fill the mold completely and avoid solidification during the casting process.

High pressure die casting uses two distinct velocities. The molten metal is first pushed at a low velocity (initial velocity) in order to avoid turbulence and the formation of bubbles. Just before the material enters the mold, the velocity increases (second phase velocity), and the molten metal is injected very quickly into the die assembly to fill it completely.

Define High Pressure Parameters

  1. Click next to the Basic Setup icon, then select High Pressure.

    The High Pressure Process Setup window opens.
  2. Define the high pressure process parameters.

    If no shot sleeve is present in the model, the High Pressure Process Setup window will appear as shown below.

    If a shot sleeve is present in the model, the High Pressure Process Setup window will appear as shown below.
  3. Right-click and mouse through the check mark to exit, or double-right-click.

High Pressure Options

Without Shot Sleeve
When no shot sleeve is included in the model, the High Pressure Process Setup window includes these controls:
Initial Velocity (m/s)
Typical values for Initial Velocity are 0.2–0.5 m/s.
Second Phase Velocity (m/s)
Typical values for Second Phase Velocity are 2.0–5.0 m/s.
Phase Change Point
To specify where the initial velocity changes to the second phase velocity, click Select, and then click a point on the runner.
Tip: The phase change point needs to be on the runner, before the material enters the mold.

Create Shot Sleeve
Click this button to open the Add/Edit Shot Sleeve tool and create a shot sleeve. When you exit the tool, the High Pressure Process Setup window will appear as described below.
Compute Clamping Forces
Enable this option to have the solver calculate the force necessary to keep the mold closed during casting. Clamping force is the product of the separation force for the mold and a user-editable safety factor. View the result and edit the safety factor in the Analysis Explorer.
Intensification Pressure
This is the maximum pressure applied during the casting process. The value defaults to 600 Kg/cm2 (or 60 MPa). This field is editable when Compute Clamping Forces is enabled.
Opening Direction
This is the axis along which the mold will open. The solver uses this information when determining the clamping force.
Note: Intensification Pressure and Opening Direction are available when Compute Clamping Forces is enabled.
With Shot Sleeve
When a shot sleeve is included in the model, the High Pressure Process Setup window includes these controls:
Filled Sleeve
Select Mass to define the quantity of metal introduced in the piston shot sleeve in kg or Sleeve filled % to enter the percentage that the piston shot is filled after pouring the liquid in.
Note: By default Mass will be automatically computed as the volume of the selected part plus the runner.
Piston Velocity Control
Select By position or By time, and define the piston velocity profile.

By position allows you to select the first and second velocity when the liquid reaches a selected position on the shot sleeve. The final position will be automatically edited depending on the designed shot sleeve length.

By time allows you to select the first and second piston velocity with respect to the filling time.

You can enter values in the table or edit the points on the graph. Click to add a new row after a selected data point, add a new row after the last data point, or delete a selected row.
Click icon to open the velocity plot. You can drag the points on the plot to edit them.
PQ2 Diagram
Enable the Show PQ2 diagram option to reveal this tool. It can help you improve the machine setup in the high-pressure die casting process. The diagram shows a green safety region on a pressure vs flow rate graph. The safety area is defined by the minimum and maximum pressure and minimum and maximum flow rate during the casting process.
Note: The PQ2 diagram and its parameters are useful only when the model includes a shot sleeve.


The yellow Current Setup point in the diagram shows the current machine setup based on the settings in the Piston Velocity and Ingate Area fields.

Machine Parameters
Piston Velocity Void
This is the maximum dry shot speed. Edit this field to change the position of the yellow Current Setup point in the diagram.
Hydraulic System Pressure
This is the hydraulic pressure in the machine. Edit this field to change the black Machine Line in the diagram.
Hydraulic Cylinder Piston Diameter
Diameter of the piston in contact with the hydraulic system. Edit this field to change the black Machine Line in the diagram.
Hydraulic Cylinder Tailrod Diameter
Diameter of the rod on the hydraulic system end. Edit this field to change the black Machine Line in the diagram.
Pressure Parameters
Discharge Coefficient
This is the ratio of the actual discharge to the ideal discharge. Values range from approximately 0.5 to 0.7, depending on the material. Edit this field to change the black Machine Line in the diagram.
Minimum Ingate Velocity
Minimum velocity at the ingate that will cause material atomization. Edit this field to change the red Minimum Pressure Line in the diagram.
Maximum Ingate Velocity
Maximum velocity allowed at the ingate to avoid mold erosion. Edit this field to change the green Maximum Pressure Line in the diagram.
Ingate Area
The total area of all ingates. Edit this field to change the position of the yellow Current Setup point in the diagram.
Note: Editing this field will not change the geometry of your model. You must edit your model manually.
Advanced Parameters
Solidification Constant
This constant is based on the part's material and the mold's material, and is used to determine maximum filling time. Refer to the table below for the appropriate constant. For example, when creating a part made of Iron using a Tungsten mold, the solidification constant would be 12.4. Edit this field to change the blue Minimum Flow Rate Line in the diagram.
Table 1. Solidification Constants
Part Material Mold Material
  P-20 H-13/H-21 Small Casting H-13/H-21 Large Casting Tungsten
Mg - 34.09 47.24 12.4
Al 360, 380, 384 - 34.09 47.24 12.4
Al 390 - 34.09 47.24 12.4
Zn 12, 27 31.2 34.09 47.24 12.4
Zn 3, 5, 7 31.2 34.09 47.24 12.4
Fe - 34.09 47.24 12.4
Cu 60/40 - 34.09 47.24 12.4
Cu 85-5-5-5 - 34.09 47.24 12.4
Pb 15.6 17.05 23.62 12.4
Part Thickness
This is the average part thickness. Edit this field to change the blue Minimum Flow Rate Line in the diagram.
Maximum Allowed Solid Fraction
Maximum solid fraction that is allowed at the end of the filling stage. Edit this field to change the blue Minimum Flow Rate Line in the diagram.
Maximum Allowed Solid Fraction Constant
This constant is based on the part's material. Refer to the table below for the appropriate constant. For example, when using Iron to create a part, the maximum allowed solid fraction constant would be 600. Edit this field to change the blue Minimum Flow Rate Line in the diagram.
Table 2. Maximum Allowed Solid Fraction Constants
Material Constant (°C)
Mg 250
Al 360, 380, 384 380
Al 390 380
Zn 12, 27 320
Zn 3, 5, 7 250
F3 600
Cu 60/40 470
Cu 85-5-5-5 470
Pb 210
Compute Clamping Forces
Enable this option to have the solver calculate the force necessary to keep the mold closed during casting. Clamping force is the product of the separation force for the mold and a user-editable safety factor. View the result and edit the safety factor in the Analysis Explorer.
Intensification Pressure
This is the maximum pressure applied during the casting process. The value defaults to 600 Kg/cm2 (or 60 MPa). This field is editable when Compute Clamping Forces is enabled.
Opening Direction
This is the axis along which the mold will open. The solver uses this information when determining the clamping force.
Note: Intensification Pressure and Opening Direction are available when Compute Clamping Forces is enabled.