Enhanced wear resistance of the Cr-based thin film coating on micro drill by doping with W–C–N

• Published in: Thin solid films Vol. 517; no. 17; pp. 5197 - 5201
• Main Authors: Chu, C.W., Jang, Jason S.C., Chen, H.W., Chuang, T.L.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-07-2009; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Exact sciences and technology; Hard films; Materials science; Mechanical and acoustical properties; Methods of deposition of films and coatings; film growth and epitaxy; Micro drill; PCB; Physical properties of thin films, nonelectronic; Physics; PVD coating; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Micro drill; PVD coating; Hard films; PCB; Scratching test; Atomic force microscopy; Nanoindentation; Chromium nitride; Tungsten additions; Mechanical properties; Printed circuit board; Friction factor; Hardness; Acetylene; Thin films; Transmission electron microscopy; Tungsten; Wear; Chromium; Physical vapor deposition; Wear resistance; Microstructure; Protective coatings; Tribology
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2009.03.052

The microstructure and performance of micro drills coated with Cr, Cr
2N, and CrWCN thin films for applying to drill the PCB (printed circuit board) at high rpm (400 krpm) were systematically investigated by means of AFM, TEM, nano indentation and scratch test in this study. The results of properties evaluation for these coatings on the tungsten drill samples revealed that the doping of W accompanied with pursing C
2H
2 gas on the Cr
2N coating effectively increases the hardness of Cr
2N film from 8 GPa to 25 GPa and decreases the frictional coefficient from 0.35 to 0.25. In addition, when these three thin films were applied on the on-line test of drilling the PCB for 24,000 holes, the CrWCN thin film shows the best wear resistance among these three thin films, presenting the minimum flank wear and 4–5 times longer tool life than the uncoated samples. Therefore, the CrWCN thin film is suggested to be a prominent material for protective coatings according to its excellent wear resistance and adhesive capability.