Fundamental investigation on the use of cryogenically generated additive support structures and damping elements for the stabilisation of the milling process when machining thin-walled components

• Applicant: Professor Dr.-Ing. Dirk Biermann
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 515938217

Dynamic effects often limit the productivity of machining processes. Especially when machining thin-walled components, it is important to avoid dynamic effects that can lead to undesired periodic relative deflections between tool and workpiece. The modal properties of a dynamic system can be characterised by its structural stiffness and damping as well as by its modal mass. The presented project approach describes a novel method for process stabilisation by targeted manipulation of the structural properties of thin-walled components. For this purpose, ice media such as water or cooling lubricant emulsion are cooled using a cryogenic medium and sprayed onto a component, where they form a snow layer which acts as a supporting and damping element. This method is particularly interesting because, in comparison to other approaches, it enables the stabilising structures to be easily removed without leaving any residue, which eliminates the need for further post-processing. In the course of experimental investigations, a far-reaching potential for process stabilisation has been demonstrated, which enables an increase in process efficiency and productivity in the machining process. The aim of the described project initiative is the fundamental research of the interrelations between the cryogenically sprayed support and damping elements and the process dynamics. For this purpose, fundamental findings on the generation as well as the structural-mechanical properties of different ice structures are first collected (glaciology) and then their influence on process stabilisation is evaluated (dynamics). In order to determine the causal relationships between ice media, application strategies and process behaviour and to gather basic knowledge in the field of process stabilisation, an investigation of the basic mechanisms of action is therefore to be carried out and influencing factors analysed experimentally and on the basis of models. For the simulation-based analysis of the process behaviour of thin-walled workpieces with cryogenically generated support and damping structures, a geometric-physical process simulation is to be used and specifically adapted, to allow an optimisation of the hybrid manufacturing process.

• DFG Programme: Research Grants