Titanium alloy (Ti6Al4V) substrates were deposited with smooth multilayer coatings, by hot filament chemical vapour deposition technique. The effect of boron doping on lattice parameter, residual stresses, hardness and coefficient of friction in multilayer-diamond coating system was studied. The frictional behaviour of the coatings was studied using a ball-on-disc micro-tribometer by sliding the coated samples of titanium alloy (Ti6Al4V) substrates against alumina (Al2O3) balls, and increasing normal load from 1 to 10N. The average friction coefficient decreased from 0.36 to 0.29 for undoped multilayer-diamond coating system and from 0.33 to 0.18 for borondoped (BD) multilayer-diamond coating system. The average indentation depths for undoped and BD multilayerdiamond coating systems were found to be equal to ∼58 and ∼65 nm, respectively, and their hardness values were 60 and 55GPa, respectively. © 2016 Indian Academy of Sciences.

Mamidanna Sri Ramachandra Rao

Department Of Physics

K. Ramasubramanian

Alumina

Aluminum

Aluminum coatings

boron

Chemical vapor deposition

Diamonds

Friction

Hardness

Multilayers

SYNTHETIC DIAMONDS

titanium

Titanium alloys

tribology

BORON-DOPING

Chemical vapour deposition

Coefficient of frictions

CVD DIAMOND COATINGS

Friction coefficients

INDENTATION DEPTH

MECHANICAL AND TRIBOLOGICAL PROPERTIES

MULTI-LAYER-COATING

Coatings

Fulltext

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Bulletin of Materials Science

We report a new industrial application of diamond coatings, by depositing diamond thin films on tungsten carbide (WC-Co) riveting inserts to achieve improved wear resistance and tribological behavior. The riveting inserts are widely used by chain manufacturing industries to guide the pin through its groove. Diamond coatings were deposited on the WC-Co riveting inserts by using hot filament chemical vapor deposition technique. Deposited films were characterized by using X-ray diffraction, a scanning electron microscope (SEM), Raman spectroscopy and a nanoindenter. The SEM micrograph of the deposited films revealed different surface morphologies and crystallite sizes in the groove and in the flat region of the riveting insert. The results concerning the different morphologies and crystallite sizes on the substrate surface are discussed. The coated riveting inserts showed an enhanced performance in the preliminary applied test. © 2012 Elsevier Ltd. All rights reserved.

International Journal of Refractory Metals and Hard Materials

Chemical vapor deposition of diamond coatings on tungsten carbide (WC-Co) riveting inserts

In this work, integrated composite diamond (ICD) coatings have been achieved with top layer nanocrystallinity, low friction coefficient and enhanced integrity. ICD coatings were deposited on chemically treated tungsten carbide (WC-Co) substrates using hot filament chemical vapour deposition technique. Nanocrystalline diamond (NCD) layer was deposited over microcrystalline diamond (MCD) layer with a coating architecture of NCD/transition layer/MCD/WC-Co. Graded transition layer thickness of ∼ 1 μm was realized by controlling the process parameters such as methane concentration and chamber pressure in order to integrate the MCD and NCD layers. Integrity of the coatings was examined by the cross-sectional studies. Structural and microstructural characteristics of ICD coatings were compared with those of MCD coatings. The measured average nanohardness of ICD coating was ∼ 96 GPa. A low and stable friction coefficient of ∼ 0.06 was observed for ICD coatings against silicon nitride (Si3N4). ICD coatings were anticipated to exploit the advantages of both NCD and MCD coatings and these coatings can be promising candidates for various mechanical applications. © 2012 Elsevier Ltd. All rights reserved.

Growth and characterization of integrated nano- and microcrystalline dual layer composite diamond coatings on WC-Co substrates

Macromolecular Materials and Engineering

Macromol. Mater. Eng. 7/2018

Surface and Coatings Technology

Tribological, anti-corrosive properties and biocompatibility of the micro- and nano-crystalline diamond coated Ti6Al4V

Thin Solid Films

Doped diamond electrodes on titanium substrates with controlled sp2/sp3 hybridization at different boron levels

Influence of boron doping on mechanical and tribological properties in multilayer CVD-diamond coating systems

Journal	Bulletin of Materials Science
Publisher	Indian Academy of Sciences
ISSN	02504707
Open Access	No