Machining of deep holes in challenging dimensions

Biermann, D.1, a; Iovkov, I.1, b; Jaeger, J.1; Metzger, M.1, c

Institut für Spanende Fertigung, Technische Universität Dortmund, Baroper Str. 303, 44227 Dortmund

a); b); c)


Machining of deep boreholes with a high length-to-diameter ratio (l/D) is challenging itself, however this paper contains three applications with further enhanced requirements. In the first section, a new solution for cryogenic machining of challenging materials and dimensions is presented. Here, a small amount of lubricant is dissolved in CO2 to combine advantages of cryogenic and MQL machining. The second topic shows current developments for the reduction of heat input and straightness deviation when machining complex gear shafts. Thereby, three parallel deep boreholes with an l/D ≈ 60 have to be produced with a high straightness accuracy to avoid their crossing in high depth. The third chapter focuses on the development of a new chamber boring tooling system for bottom forming in deep boreholes.


Deep hole drilling, combined MQL-cryogenic cooling, thermal workpiece distortion, internal profiling


4. Wiener Produktionstechnik Kongress: Efficiency, Flexibility, Integration, new academic press, Wien, September, 26-27, (2018), S. 125-129, ISSN 978-3-7003-2086-9