QForm-Extrusion

QForm-Extrusion

Extrusion Simulation and Optimisation Software


QForm-Extrusion is a special-purpose program for aluminium profile extrusion simulation and optimisation. The program has an excellent interface for preparing the source geometry and performing the simulation. QForm-Extrusion provides the information about the material flow during profile extrusion, of the profile shape, load, temperature and strain distribution depending on technological parameters and die design. The software is very effective for industrial implementation by die makers and/or profiles producers to reduce their development time and cost.

QForm Extrusion

QForm-Extrusion is a single program that integrates all the features required for analysis and optimization of the most complicated extrusion processes. It is being successfully used for simulation of solid, semi-hollow and hollow profiles as well as extrusion through multi-hole dies. The extruded material can be aluminum alloys, brass, steel and other metals.

The program is fast and reliable. It works on a 64-bit hardware platform and takes advantage of parallel computing on PCs with up to 8 CPUs under Windows. A series of simulations can be run overnight or over weekends using the built-in batch mode.

Benchmark test — experimental proof of simulation results

The test extrusion was done for four angular profiles going through a multi-hole die. Use of different shapes of the chambers has caused variation of extrusion velocities for each profile. QForm-Extrusion simulation has shown very good correspondence of the profile velocities with the experiment.

QForm Extrusion

Working with the program

The function of the program is illustrated by the following simulation steps for a hollow profile.

The geometry of the die set is imported as 3D models from a CAD system using standard STEP or IGES formats.

The bearing zone of the die is automatically converted into parametric representation before the mesh is generated. The bearing lengths are extracted from the 3D bearing curves of the CAD drawing. QForm’s built-in Bearing Editor allows interactive modification of the bearing lengths and the choke angles without requiring the user to go back to their CAD system.

The program automatically creates high quality mesh in the domain of the material flow.

QForm Extrusion

Other process parameters such as material data, press speed, preheat temperature etc. are specified by the Data Preparation Wizard.

The simulation is performed by Euler-Lagrange method and shows impressive performance and accuracy. The profile shape is displayed concurrently with the progress of the simulation along with distribution of the velocity or any other parameter. The front tip obtained by simulation looks very similar to the real one and load prediction, profile temperature, and die stress also have good correspondence with reality.

QForm-Extrusion output

During virtual trials the user can see the extruded profile shape and all the parameters of the process such as velocity distribution along the profile evolute, profile temperature, required press load, contact stress etc. Using this information the user can identify the cause of the flow imbalance and make necessary corrections performing “what-if” studies to achieve the best performance.

QForm Extrusion

Velocity and the profile shape

Longitudinal velocity distribution at different instants of the hollow profile extrusion clearly shows that the velocity variation in the profile is greater when the material just starts to flow out of the die. With the addition of a front-end extension, the velocity in different parts of the profile has less variation due to the holding effect of the rigid part of the profile. This demonstrates the need to simulate a certain length of the profile before making a decision about correct die design.

QForm Extrusion

Thermal analysis of the process

Coupled flow and thermal simulation provides accurate prediction of the process heat balance taking into consideration heat generation due to plastic work and heat loss due to contact with the tooling set as well as material flow. The simulation shows what optimal billet preheat, press velocity and die temperature are needed to get the exit temperature within the desired range.

Technological and metallurgical study

Comprehensive analysis of the material state during the process is provided by tracking the material particles that go through the die. All the parameters of the material state are recorded in these particles. This method allows for the tracking of surface impurities preventing them entering the profile, as well as indicating the transverse weld length. It can also be used for metallurgical analysis of the extruded material.

QForm Extrusion

Case study: bearing design optimization for hollow angular profile

Varying the bearing design is the main method to achieve desired uniform material flow through extrusion dies. In practice non-uniform material flow is clearly seen when looking at the front tip of the profile. The front tip is formed when the material flow is free and no restrictions are applied by the part of the profile that has already left the die orifice. Thus the front tip shape is very sensitive to non-uniform velocity and is a good indicator of the quality of the die design.

Simulation by Qform-Extrusion clearly shows the front tip shape that corresponds to practical observations. To show how the simulation can be used for practical purposes let us consider the extrusion of a hollow angular profile. The simulation shows the same directional deformation of the front tip of the profile as in the real extrusion.

QForm Extrusion

The reason for this shape deterioration is much lower metal velocity in the “corner” of the profile than in the “legs”. Bearing Editor displays the evolutes of the bearing length of all contours of the profiles (outer and inner) and shows them as graphs.

Moreover after completing the simulation, Bearing Editor displays the evolute of the velocity profile on the same graph as the evolute of the bearing length that shows how they correspond to each other.

For this particular angular profile, the initial reduction of the bearing length in the corner area of the profile was not enough to equalise the velocity (fig. 3, left picture). With further reduction of the bearing length in the corner area, the velocity becomes uniform and the front end of the profile becomes straight (fig. 3, right picture). Use of simulation for optimisation of bearing design saves time and money by giving successful results without the need for real tests.