Surface Quality after Broaching with Variable Cutting Thickness

During machining, new surfaces are generated. Depending on the machining process, different qualities of surfaces are produced. After broaching, a high surface quality is expected. However, the quality can be influenced by vibrations of the machine structure which leads to varying cutting thicknesses and thus to low surface qualities. The influence of variable cutting thicknesses during machining was investigated experimentally and by means of simulations. Dynamic changes in cutting thickness were considered as geometrical profiles on the uncut surfaces. Process forces were measured during the experiments and the roughness before and after broaching with one tooth was evaluated. The residual stresses in the workpiece surfaces were simulated with an already validated model of orthogonal machining using a self-implemented re-meshing method.