Numerical simulation of process forces during re-contouring of welded parts considering different material properties

Repair techniques for high-value components offer a huge economical and ecologic potential, but are rarely investigated in science, yet. One main step of the process chain for regeneration of damaged components is the removal of excess weld material, called re-contouring, which is often carried out manually nowadays. Although there are special automated software solutions using milling machines for re-contouring, changing material properties and microstructure as well as changing engagement conditions due to welded or brazed areas are not considered in tool path planning. This paper presents a research approach in which the influence of the material inhomogeneity and discontinuous shape of weld on the machining processes for re-contouring is investigated. A numerical simulation is used to calculate the process forces accurately per time step with consideration of changing material properties. The experimental and numerical investigations prove a much higher influence on the changing engagement conditions due to geometrical variations of the weld compared to the influence of material inhomogeneity due to welding.