Compensation of shape and dimensional deviations due to thermo-elastic deformation during dry machining

 

Due to the development of cutting materials in cutting technology, it is now possible in many applications to replace machining processes, where cutting fluid is used, completely by dry machining or by using only a minimum quantity lubrication strategy. In this way, it is possible to save costs for the provision, maintenance and disposal of various cutting fluids. However, dispensing with cooling lubricants in dry machining changes the generated process heat and its distribution within the system, consisting of tool, workpiece, chips and machine tool environment. Consequently, the tool and the workpiece as well as adjacent system components are exposed to a temperature change during the cutting process, which in the case of metallic materials is usually accompanied by thermal expansion. The thermal expansion results in deformation of the workpiece and in undesired displacements of the machine components and therefore leads to shape and dimensional deviations of the manufactured workpieces. Due to the temporal and spatial complexity of the physical processes involved, the occurring deformations cannot be compensated by simple analytical calculations or empirical knowledge, but are iteratively reduced by means of complex and cost-intensive pre-tests.

Therefore, in this research project a simulative multi-scale approach is pursued, in which the compensation of thermo-elastic deformations is implemented for the first time on the basis of a real application case and thus transferred to industrial practice. Subsequently, strategies for the compensation of such displacements and deformations can be derived, which allow dry hard turning of complex components with high requirements on form and dimensional accuracy.