A simple approach for the optimization of deep rolling and burnishing processes

The mechanical surface treatment by deep rolling and burnishing is a widely used process in many industrial applications to optimize surface characteristics such as roughness, hardness and the residual stress state. Multiple process parameters (contact pressure, feed rate, tool diameter) need to be adapted to achieve an optimal treatment result, requiring major experimental efforts for the optimization process. Therefore, an approach was developed to simplify the optimization. The single target parameter for optimization in this approach is the overlap factor. This overlap factor can be simply determined experimentally from the width of single tracks, theoretically by Finite Element Analysis (FEA) or analytically by assuming linear elastic contact (Hertzian contact). The overlap factor was correlated with the surface condition after treatment (roughness, residual stress state) and an optimum value was proposed based on the treated material. For verification, the new approach was applied to Laser Bed Powder Fusion (LBPF) manufactured materials made of AlSi10Mg and 316L. To avoid overtreatment, i.e. an extensive plastic deformation of the surface during the process, an overlap factor of max. 90% was recommended based on former results. The predicted process parameters show the highest surface quality in this investigation.