An Experimental Study on Hole Quality and Different Delamination Approaches in the Drilling of CARALL, a New FML Composite

Ekici E. , Motorcu A. R. , Yıldırım E.

FME Transactions, vol.49, no.4, pp.950-961, 2021 (Refereed Journals of Other Institutions)

  • Publication Type: Article / Article
  • Volume: 49 Issue: 4
  • Publication Date: 2021
  • Doi Number: 10.5937/fme2104950e
  • Title of Journal : FME Transactions
  • Page Numbers: pp.950-961


In this study, the hole quality was investigated in the drilling of CARALL composite. In addition, the delamination factor calculation approaches of Chen, Davim, and Machado were compared in terms of the delamination damage at the hole entrance surface. Chen's approach is based on the conventional delamination factor (Fd) and Davim's on the adjusted delamination factor (Fda). Finally, Machado's approach is based on the minimum delamination factor (Fmin). The values closest to the nominal hole diameter value were obtained with the uncoated (T1), followed by the TiNTiAlN-coated (T2) and TiAl/TiAlSiMoCr-coated (T3) carbide drills, respectively. The average circularity error values for the hole top and bottom surfaces were 6.184 μm, 7.647 μm, and 8.959 μm for T1, T2, and T3 tools, respectively. Delamination factor values varied between 1.174 and 1.804. The Fda values were found to be the highest, followed by Fd values, with Fdmin values determined as the lowest.