Analyzing the performance of diamond-coated micro end mills

• Published in: International journal of machine tools & manufacture 2009-06, Vol.49 (7), p.599-612
• Main Authors: Torres, C.D., Heaney, P.J., Sumant, A.V., Hamilton, M.A., Carpick, R.W., Pfefferkorn, F.E.
• Format: Article
• Language: English
• Subjects: ADHESION; ALUMINIUM; Applied sciences; CHEMICAL VAPOR DEPOSITION; Coating; COATINGS; Cross-disciplinary physics: materials science; rheology; DIAMONDS; Exact sciences and technology; Fine-grained diamond (FGD); FRICTION; Hot-filament chemical vapor deposition (HF-CVD); INTERFEROMETRY; MACHINING; MATERIALS SCIENCE; Mechanical engineering. Machine design; Methods of deposition of films and coatings; film growth and epitaxy; Micro end milling; MILLING; MORPHOLOGY; Nanocrystalline diamond (NCD); NUCLEATION; Physics; TESTING; TUNGSTEN CARBIDES
• ISSN: 0890-6955; 1879-2170
• DOI: 10.1016/j.ijmachtools.2009.02.001

A method is presented to improve the tool life and cutting performance of 300 μm diameter tungsten carbide (WC) micro end mills by applying thin (50%). Reduction of the cutting forces is attributed to the low friction and adhesion of the diamond coating. However, approximately 80% of the tools coated with the larger FGD coatings failed during testing due to delamination. Additional machining benefits were attained for the NCD films, which was obtained by using a higher nucleation density seeding process for diamond growth. This process allowed for thinner, smaller grained diamond coatings to be deposited on the micro end mills, and enabled continued operation of the tool even after the integrity of the diamond coating had been compromised. As opposed to the FGD-coated end mills, only 40% of the NCD-tools experienced delamination issues.