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M.Sc. Matthias Zapf

Research Associate
department: Manufacturing and Materials Tech-nology
office hours: To be agreed
room: 102, Geb. 10.92
phone: +49 1523 9502634
Matthias ZapfRxn1∂kit edu

76131 Karlsruhe
Kaiserstraße 12

M.Sc. Matthias Zapf

Area of Research:

  • Gear Skiving
  • Electric Discharge Machining


General Tasks:



  • Skiving of hardend steel
  • Skiving of high-tensile internal gears


Test benches:


[ 1 ] Vargas, B.; Zapf, M.; Klose, J.; Zanger, F. & Schulze, V. (2019), "Numerical Modelling of Cutting Forces in Gear Skiving". Procedia CIRP 82, eds. Elsevier B.V., pp. 455-460.
Gear skiving is a high-performance machining process for gear manufacturing. Due to its complex kinematics, the local cutting conditions vary during tool engagement. Particularly, the local rake angle can reach highly negative values, which have a significant effect on the cutting force. In this paper, the Kienzle force model with additional coefficients was implemented in a numerical model to calculate local cutting forces considering the influence of local rake angle. The experimental validation based on total cutting forces shows good results and indicates an increase of model accuracy for a wide parameter range by considering the rake angle Variation.

[ 2 ] Zapf, M.; Klose, J.; Zanger, F. & Schulze, V. (2019), "Process forces and surface topography when manufacturing case-hardened gears by double flanked hard skiving". VDI Berichte 2355, eds. VDI Wissensforum GmbH, pp. 1647-1658.
Due to its kinematics, gear skiving offers high potential for hard finish machining of internal and external gears to substitute gear grinding. Single flanked hard machining by skiving offers stable processes, because there’s only one flank in contact during cutting, but is much less productive than double flanked machining. Double flank hard finish machining is highly productive when finishing in one process step. The complex kinematics of skiving are characterized by their asymmetric chip formation due to an irregular cutting thickness of the leading and trailing flank. In this work the influence of process parameters such as cutting velocity, axial feed and radial feed of the finishing cut on the cutting forces, the resulting gear quality, flank surface quality and chip formation is investigated. The parameter studies are carried out in an analogy process using coated cemented carbide inserts with 3 cutters. Validation of the analogy process is provided by experiments with fully toothed tools. In-process force measurements supports the accurate analysis of wear mechanisms of the cemented carbide tools and the chip formation. Process forces are high due to the hardness of the workpiece and rise with the specific cutting volume. The correlation of cutting forces and surface quality with other process parameters shows more complex parameter interaction. The results support industrial acceptance of skiving as a highly productive machining process for hard finish machining and as an alternative to gear grinding and honing.