An Investigation into the Adhesion Strength of Diamond Like Carbon Multilayer Coating (DLC/TiN/Ti/Cu/Ni)

Advancement in vacuum technologies and vapor deposition processes during last decades has led to the introduction of many modern coatings on metal cutting tools. Even in such an advanced vacuum coating techniques, the failure is not due to the wear of the coating but rather due to the lack of coating adhesion to the substrate. In this work, the coating adhesion test results were performed which is based on the Rockwell indentation tests. This coating adhesion tests were performed as per VDI standards 3198, 1991 for d.c. magnetron sputter deposition of diamond like carbon multilayer coating (DLC / TiN/ Ti / Cu / Ni) on tool substrate. Multilayer coating was deposited on tool substrates at different sputtering parameters/conditions such as power density, partial pressure, substrate temperature and reactive gases. The coated multilayer films were characterized by experimental techniques such as X-ray diffractometer which measures the material deposited, micro Raman spectroscopy and TEM to check DLC, Rockwell indentation to examine adhesion strength, optical profilometer to measure thickness of coating. Ni increases the Cu adhesion on tool substrate. Cu accommodates the shear stress induced by the films / substrate and the mismatch in thermal expansion coefficient, while Ti and TiN promote better DLC bonding. As the target power was increased the adhesion strength, micro hardness and deposition rate were observed to improve. Increase in target power and substrate temperature enhances adhesion strength. Proper substrate preparation and sequence of cleaning processes are the crucial factors for the enhancement of adhesion strength. The sputter deposition conditions for the above mentioned multilayer coatings are identified in this work to get improved quality with particular reference to adhesion and surface finish.

[1]  P. Shewmon.  Diffusion of impurities along surfaces , 1967 .

[2]  P. Kelly,et al.  Magnetron sputtering: a review of recent developments and applications , 2000 .

[3]  S. Schiller,et al.  A new sputter cleaning system for metallic substrates , 1976 .

[4]  B. Bhushan,et al.  Handbook of Tribology: Materials, Coatings, and Surface Treatments , 1991 .

[5]  A. Volinsky,et al.  Investigation of microstructure and mechanical properties of multi-layer Cr/Cr2O3 coatings , 2009 .

[6]  G. Rhead.  Diffusion on surfaces , 1975 .

[7]  A. Naumovets,et al.  Surface diffusion of adsorbates , 1985 .

[8]  J. Lin,et al.  The study of adhesion and nanomechanical properties of DLC films deposited on tool steels , 2009 .

[9]  M. Watanabe,et al.  Evaluation of adhesion strength of thin hard coatings , 1987 .

[10]  D. M. Mattox.  Thin film metallization of oxides in microelectronics , 1973 .

[11]  John Robertson,et al.  Deposition mechanisms for promoting sp3 bonding in diamond-like carbon , 1993 .

[12]  John Robertson,et al.  Diamond-like carbon , 1994 .

[13]  H. Bonzel.  A surface diffusion mechanism at high temperature , 1970 .

[14]  M. W. Thompson.  Physical mechanisms of sputtering , 1981 .

[15]  B. Bhushan.  Modern Tribology Handbook, Two Volume Set , 2000 .

[16]  D. M. Mattox,et al.  Interface Formation during Thin Film Deposition , 1963 .

[17]  J. Venables.  Nucleation and growth of thin films: recent progress , 1983 .

[18]  D. M. Mattox.  Surface effects on the growth, adhesion and properties of reactively deposited hard coatings , 1996 .

[19]  Hideaki Adachi,et al.  Thin Film Materials Technology: Sputtering of Compound Materials , 2004 .

[20]  S. Bull.  Techniques for improving thin film adhesion , 1992 .

[21]  P. Kiryukhantsev-Korneev,et al.  Structure and properties of multi-component and multilayer TiCrBN/WSex coatings deposited by sputtering of TiCrB and WSe2 targets , 2008 .

[22]  Nikolaos Bilalis,et al.  The vdi 3198 indentation test evaluation of a reliable qualitative control for layered compounds , 2003 .

[23]  H. Weiss.  Adhesion of advanced overlay coatings: mechanisms and quantitative assessment , 1995 .

[24]  D. S. Rickerby,et al.  The relationship between hardness and scratch adhession , 1987 .

[25]  O. Salas,et al.  Deposition of AlN on Al substrates by reactive magnetron sputtering , 2005 .

[26]  Yaogen Shen,et al.  Mechanical and tribological properties of nanostructured TiN/TiBN multilayer films , 2008 .

[27]  Lars Hultman,et al.  Microstructural design of hard coatings , 2006 .

[28]  U. Wiklund,et al.  The influence of metallic interlayers on the adhesion of PVD TiN coatings on high-speed steel , 2008 .

[29]  E. Levashov,et al.  Effect of nitrogen partial pressure on the structure, physical and mechanical properties of CrB2 and Cr–B–N films , 2009 .

[30]  E. Bourhis.  Indentation mechanics and its application to thin film characterization , 2008 .

[31]  S. Vepřek,et al.  A concept for the design of novel superhard coatings , 1995 .

[32]  Chii-Ruey Lin,et al.  Improvement in adhesion of diamond films on cemented WC substrate with Ti–Si interlayers , 1998 .

[33]  Bharat Bhushan,et al.  Nanomechanical characterisation of solid surfaces and thin films , 2003 .

[34]  Kanghua Chen,et al.  Characteristics and performance of Ti(C, N) coatings synthesized by magnetron sputtering technique , 2009 .

[35]  D. M. Mattox,et al.  Chapter 2 Adhesion processes in the technological applications , 1986 .