Subproject C1 Process Design

Currently, re-contouring of components of complex capital goods is a manual and iterative process based on the knowledge of individual workers. The sub project C1 aims at the automatized planning of the re-contouring. Therefore, a geometric process simulation of the milling process and the upstream material deposit is developed. Modeling of surface parameters allows an evaluation of the process concerning part quality.

Motivation and objectives

Current Process and challenges in re-contouring

Due to its impact on the components function in relation to the entire system, the re-contouring is an important sub-process in repair of complex capital goods. Due to the individuality, each component of the capital good represents a batch size one process. Hence, in planning of the re-contouring process manual CAD/CAM methods are state of the art. This results in uncertain and unreproducible repair processes for each component.

The goal of the sub-project is an algorithm for the automatic planning of the re-contouring process. Inside the planning algorithm, an evaluation and adaption of the process is carried out. The aim is to gain part quality aspects that satisfy the requirements resulting from the functional review. The evaluation includes a geometric, dexel-based process simulation. Based on empirical process models, the individually simulated tool engagement conditions are correlated with quality parameters. The subsequent process adaption leads to a process that satisfies the required quality criteria for an individual component.

Re-contouring of an analog blisk on the 5-axis milling center Deckel Maho DMU 125P


A prototype for the planning algorithm has been implemented based on the simulation software IFW CutS, and an interface to a commercial CAM system. Within large experimental studies it has been shown which process parameters have significant impact on the subsurface of complex parts. Engine blades made of titanium and nickel base alloys have been the subject of investigation. Tool angles as well as cutting edge micro geometries have a major impact on sub surface residual stresses. Two geometric process parameters have been developed. The surface-generating forces enable the prognosis of process induced residual stresses. The surface generating cut volume furthermore leads to an evaluation of residual stresses induced part distortion for the considered material. This is of importance when re-contouring thin-walled compressor blades. These parameters allow the technological evaluation and adaption of individual re-contouring processes in the planning algorithm.

Planning algorithm for re-contouring

Current research and outlook


The aim of sub-project C1 in the 3rd funding period is to extend the automated process planning and simulation to the welding material application, and to improve the prognosis of surface quality after material removal. This will enable joint planning to take place for the first time, taking into account the technological interactions between the regeneration processes. A repair-specific data model is being developed in sub-project C1, which stores the necessary information of a process for an individual component and makes it available to all other processes with the addition of a tolerance. This CAD-based work piece dovetails with the intelligent work piece carrier developed in the 3rd funding period in sub-project B2  to ensure cross-process planning and optimization of the regeneration according to the roadmap of the Collaborative Research Centre.

Geometric process simulation of blade re-contouring

Subproject leader

Dr.-Ing. Volker Böß
An der Universität 2
30823 Garbsen
An der Universität 2
30823 Garbsen
Prof. Dr.-Ing. Berend Denkena
An der Universität 2
30823 Garbsen
An der Universität 2
30823 Garbsen


International Scientific Journal Paper, peer-reviewed

  • Denkena, B.; Mücke, A.; Schumacher, T.; Langen, D.; Hassel, T. (2018): Technology-based Re-contouring of Blade Integrated Disks After Weld RepairJ. of Materi Eng and Perform 27, 2018 (1), 253-260
    DOI: 10.1115/1.4040738
  • Böß, V.; Rust, F.; Denkena, B.; Dittrich, M.-A. (2017): Design of individual re-contouring processesProcedia Manufacturing 14, 76-88
    DOI: 10.1016/j.promfg.2017.11.009
  • Denkena, B.; Grove, T.; Mücke, A.; Langen, D.; Nespor, D.; Hassel, T. (2017): Residual stress formation after re-contouring of micro-plasma welded Ti-6Al-4 V parts by means of ball end millingMaterials Science and Engineering Technology 2017, 1034-1039
    DOI: 10.1002/mawe.201600743
  • Böß, V.; Denkena, B.; Wesling, V.; Kaierle, S.; Rust, F.; Nespor, D.; Rottwinkel, B. (2016): Repairing parts from nickel base material alloy by laser cladding and ball end millingIn: Prod. Eng. Res. Devel. 10 (4-5), S. 433–441
    DOI: 10.1007/s11740-016-0690-7
  • Nespor D.; Denkena, B.; Grove, T.; Pape, O. (2016): Surface topography after re-contouring of welded Ti-6Al-4V parts by means of 5-axis ball nose end millingInt. J. Adv. Manuf. Technol. 85 (5-8), S. 1585–1602
    DOI: 10.1007/s00170-015-7885-5
  • Denkena, B.; Boess, V.; Nespor, D.; Floeter, F.; Rust, F. (2015): Engine blade regeneration: a literature review on common technologies in terms of machiningInt J Adv Manuf Technol 81 (5-8), S. 917–924
    DOI: 10.1007/s00170-015-7256-2
  • Nespor, D.; Denkena, B.; Grove, T.; Böß, V. (2015): Differences and similarities between the induced residual stresses after ball end milling and orthogonal cutting of Ti–6Al–4VJournal of Materials Processing Technology 226, S. 15–24
    DOI: 10.1016/j.jmatprotec.2015.06.033
  • Denkena, B.; Nespor, D.; Böß, V.; Köhler, J. (2014): Residual stresses formation after re-contouring of welded Ti-6Al-4V parts by means of 5-axis ball nose end millingCIRP Journal of Manufacturing Science and Technology 7 (4), S. 347–360
    DOI: 10.1016/j.cirpj.2014.07.001
  • Böß, V.; Nespor, D.; Samp, A.; Denkena, B. (2013): Numerical simulation of process forces during re-contouring of welded parts considering different material propertiesCIRP Journal of Manufacturing Science and Technology 6 (3), S. 167–174
    DOI: 10.1016/j.cirpj.2013.05.001

International Conference Paper, peer-reviewed

  • Denkena, B.; Pape, O.; Grove, T.; Mücke, A. (2019): Advanced process design for re-contouring using a time-domain dynamic material removal simulation.12th CIRP Conference on Intelligent Computation in Manufacturing Engineering (Hg.): Procedia CIRP 79 (2019), S. 21–26.
    DOI: 10.1016/j.procir.2019.02.005
  • Denkena, B; Mücke, A.; Schumacher, T.; Langen, D.; Grove, T.; Bergmann, B.; Hassel, T. (2018): Ball end milling of titanium TIG weld material and the effect of SiC addition – process forces and shape deviations6th International Conference on Through-life Engineering Services, TESConf 2017. 7-8 November 2017, Bremen, Germany, Seite 74-81
    DOI: 10.1016/j.promfg.2018.01.011
  • Böß, V.; Grove, T.; Denkena, B.; Mücke, A.; Nespor, D. (2016): Prediction of the Principal Stress Direction for 5-axis Ball End MillingProcedia CIRP 45, S. 291–294
    DOI: 10.1016/j.procir.2016.02.145
  • Denkena, B.; Böß, V.; Nespor, D.; Gilge, P.; Hohenstein, S.; Seume, J. (2015): Prediction of the 3D Surface Topography after Ball End Milling and its Influence on AerodynamicsProcedia CIRP 31, S. 221–227
    DOI: 10.1016/j.procir.2015.03.049
  • Denkena, B.; Böß, V.; Nespor, D.; Rust, F. (2015): Simulation and Evaluation of Different Process Strategies in a 5-axis Re-contouring ProcessProcedia CIRP 35, S. 31–37
    DOI: 10.1016/j.procir.2015.08.059
  • Denkena, B.; Böß, V.; Nespor, D.; Rust, F.; Flöter, F. (2014): Approaches for Improving Cutting Processes and Machine Tools in Re-contouringProcedia CIRP 22, S. 239–242
    DOI: 10.1016/j.procir.2014.06.148
  • Böß, V. (2012): Milling Simulation of Welded Aero Engine ComponentsProceedings of the 3rd Machining Innovations Conference, S. 403–410
  • Denkena, B.; Böß, V.; Nespor, D.; Samp, A. (2011): Kinematic and Stochastic Surface Topography of Machined TiAl6V4-Parts by Means of Ball Nose End Milling1st CIRP Conference on Surface Integrity (CSI), Bd. 19, S. 81–87
    DOI: 10.1016/j.proeng.2011.11.083

National Scientific Journal Paper, not peer-reviewed

  • Denkena, B., Grove, T., Pape, O., Mücke, A. (2018): Prozessauslegung für die Regeneration komplexer InvestitionsgüterUnter Span, Ausgabe 2018, S. 22-23
  • Rust, F. (2016): Werkzeugwege für den individuellen ReparaturfallIn: phi 2016, S. 3.
  • Samp, A. (2010): Forschen am IFW: Nach allen Regeln der Zerspankunstphi - Produktionstechnik Hannover informiert, 11 (2010) 2, S. 16-17


  • Nespor, D. (2015): Randzonenbeeinflussung durch die Rekonturierung komplexer Investitionsgüter aus Ti-6Al-4VBerichte aus dem IFW, Band 07/2015, 111 S., PZH Produktionstechnisches Zentrum
    ISBN: 978-3-95900-056-7
All publications of the Collaborative Research Centre