Process Simulation

The group institutes share an essential expertise: simulating various machining processes. Research can only understand what affects and influences machining process when it comprehensively simulates and analyzes them at high temporal and location resolution. In addition, such simulation models serve to shorten process chains when they are being designed or to transfer the processes to different fields of industrial application.

The simulations can be divided into

• Material simulations
• Simulations of coating processes
  
• Simulations of laser manufacturing processes

In the field of material modeling, Fraunhofer IST offers a wide range of services, such as material simulation for alloy and layer development, the design of heat treatments, diffusion treatments (e.g. nitriding or boriding of alloys), carburizing of steels, homogenization annealing of complex alloys or layers, and dissolving of carbides during austenitization.

For the field of thermoelectric materials, Fraunhofer IPM is working on describing the principles of heat transport, temperature distribution and interaction with the material properties essential for new thermoelectric module designs and systems. To describe such systems, Fraunhofer IPM has developed its own software tools based on Comsol and Femlab. These tools can not only be used to describe novel module constructions, but their modelling also helps to integrate these constructions into complete systems in a more optimal manner.

Fraunhofer IST and Fraunhofer FEP have a comprehensive understanding of how to simulate coating technology processes. Fraunhofer IST deals with the simulation of low-pressure coating processes (magnetron sputtering, ion beam sputtering, evaporation, hot-filament CVD and plasma-active CVD) in the field of process simulation. The institute has developed a parallelized simulation environment to model the gas and particle transport in the low pressure range. This includes the methods »Direct Simulation Monte Carlo« (DSMC) and »Particle-in-Cell Monte Carlo« (PIC-MC). Fraunhofer IST’s services include the execution of simulation studies to optimize processes and coating sources, or alternatively the software can be licensed. The institute also deals with another important topic, the optimization of the layer thickness profile on moving 3D substrates. Furthermore, from the simulations it can extract the detailed growth conditions on the substrate – e.g. particle fluxes or energy and angular distribution – in order to gain information about the layer growth in the context of further simulation models.

The work on the simulation of laser material machining processes, especially at Fraunhofer IWS and Fraunhofer ILT institutes, encompasses both answering material-related questions and understanding laser-related influencing variables. On the basis of thermodynamic conservation rates and state equations, they carry out a fundamental analysis of the examined laser material machining processes. Compared to the real process and competing technologies, these analyses help them draw conclusions about energy efficiency and achievable process efficiencies. They also focus on process analysis in order to describe how control, influencing, disturbance and target variables depend upon each other in a laser material machining processes. For this purpose, they use both numerical and experimental methods of examination.

Together with the partners from the industry, the institutes are developing fast algorithms to simulate current applications on the basis of physico-mathematical models and implementing them. Examples for this are

• »Additive Manufacturing« for dimensionally accurate components made of metal powder
• »Precision Metal Slitting« for the production of high-resolution masks for 3D displays
• »Glass Cutting« for impact-resistant touch screens of smart devices
• »Smart Metal Drilling« for cooled components in aircraft turbines
• »Sheet Metal Cutting« for various tasks of sheet metal production
• »Precision Sheet Metal Welding« for long-life spark plugs in motors
  
• »High Strength Welding« of plastic-metal compounds in automotive components

To design the processes, systems and components, the institutes use numerical processes for simulation as well as special visualization processes, such as high-speed cameras and pump-and-probe systems. With all these processes, data from the simulation and the measurement can be compared and analyzed.

In order to simulate stresses and distortion for dimensionally accurate components made of metal powder (Additive Manufacturing, Precision Sheet Metal Welding) as well as plastic-metal connections in automotive components, research needs greater knowledge of realistic material models. On the basis of more detailed, fundamental material models, the institutes are developing parametrized simulations of the thermomechanical processes during solidification for specific applications. In combination with modern numerical methods – discontinuous Galerkin method (DGM), embedded boundary condition method (EBM), chimera method – models with a large number of degrees of freedom can be solved in an appropriate amount of time.