Enhanced Surface Quality of Internal Machined Contours

Abstract

Based on integrated concepts in the aspects of product design, choice of materials and manufacturing technologies, companies in the mechanical engineering as well as oil and gas industries are striving to increase energy efficiency through weight-optimized components and manufacturing processes. With regard to the design of e.g. functional components for hydraulic systems or aircraft structures, customized manufacturing concepts are crucial in order to combine the highest product quality with the economical use of energy and resources. The use of a flexible tooling system for combined internal contouring and mechanical post-processing of boreholes developed within the framework of a ZIM project, founded by the Federal Ministry for Economic Affairs and Energy and in collaboration with BGTB GmbH makes it possible to achieve highest surface qualities of high-performance components. In order to realize a further optimization of the machined surface, the influences of increased operating pressures during roller burnishing on surface smoothing are investigated in analogy tests. In this regard, different steel types are considered as typical application materials. Based on reference tests, the surface integrity as a result of increased working pressures was analyzed as well. Besides the variation of the mechanically applied force, the adjustment of the process strategy is a central issue of the experimental investigations. On the one hand, the influences of varying roll feeds are analyzed with reference to the surface finishing quality and the process efficiency. On the other hand, different strategies for surface improvements increase by varying holding pressures are assessed comparatively.