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Ball nose end mills are usually applied during 5-axes machining of high functional parts especially in the aerospace industry. The systematical study of the relationship between process forces and kinematics, surface topography and subsurface properties is fundamental to ensure a high surface integrity. This paper deals with the topography of machined surfaces of TiAl6V4 parts by means of ball nose end milling. The machined surface has been analyzed and the kinematic topography, influenced by the process parameters and the geometry of the cutting tool, has been computed. By subtracting the surface measurements from the computed topography, the stochastic topography of the machined surface, e.g. roughness and cracks, can be determined. Furthermore, an approach is given for predicting the stochastic topography based on the process forces during machining of TiAl6V4. [ABSTRACT FROM AUTHOR]

Fused filament fabrication (FFF) is one of the most popular additive manufacturing (AM) processes due to its simplicity and low initial and maintenance costs. However, good printing results such as high dimensionality, avoidance of cooling cracks, and warping are directly related to heat control in the process and require precise settings of printing parameters. Therefore, accurate prediction and understanding of temperature peaks and cooling behavior in a local area and in a larger part are important in FFF, as in other AM processes. To analyze the temperature peaks and cooling behavior, we simulated the heat distribution, including convective heat transfer, in a cuboid sample. The model uses the finite difference method (FDM), which is advantageous for parallel computing on graphics processing units and makes temperature simulations also of larger parts feasible. After the verification process, we validate the simulation with an in situ measurement during FFF printing. We conclude the process simulation with a parameter study in which we vary the function of the heat transfer coefficient and part size. For smaller parts, we found that the print bed temperature is crucial for the temperature gradient. The approximations of the heat transfer process play only a secondary role. For larger components, the opposite effect can be observed. The description of heat transfer plays a decisive role for the heat distribution in the component, whereas the bed temperature determines the temperature distribution only in the immediate vicinity of the bed. The developed FFF process model thus provides a good basis for further investigations and can be easily extended by additional effects or transferred to other AM processes., (Copyright 2023, Mary Ann Liebert, Inc., publishers.)