Machining of functional graded workpieces by turning

Biermann, D.1, a; Zabel, A.1, b; Grünert, S.1, c

Institut für Spanende Fertigung, Universität Dortmund, Baroper Str. 301, 44227 Dortmund

a); b); c)


The finishing-process of functional components is normally effected by maching operations. Thermo-mechanical loads resulting from these processes lead to an undesirable influence on the workpiece and can reduce the functionality during their later application. Due to the power input, thermal expansions of the workpiece can occur. The consequence would be geometrical inaccuracies because of a higher material removal during the process. Moreover, the application as a functional surface may not be possible if the loads result in micro-cracks in the peripheral zone of the workpiece. Furthermore, the continuous material removal during the process can cause in an unpredictable stress distribution. This is especially the case if the workpiece is pre-loaded by previous processes e. g. by forming or hardening. If during the forming process a functional graded material behavior is produced, it means that the material characteristics vary across the part. The inhomogeneous material leads to changing cutting conditions and therefore the tool choice becomes more difficult. Normally, different tools are used when cutting ductile structures or hardened steel grades. The changing cutting conditions lead to increasing wear over time. Therefore, the resulting steadily decreasing cutting efficiency of a tool increases the friction and squeezing. The consequences are reduced surface qualities, high stressed peripheral zones, and an early tool failure. To detect these phenomena and to ensure economical and reliable machining of functional graded components, an adapted tool concept is to be realized. The results for turning functional graded components by using cemented carbide and ceramic cutting materials are presented in this publication.


Functional graded workpieces, turning, cutting material


In: Proceedings of the 2nd Manufacturing Engineering Society International Conference, CISIF-MESIC 2007, 9.7.-11.7. 2007, Madrid, Spain, ISBN 978-84-611-8001-1, digital veröffentlicht