Effect of Boron Doping on the Wear Behavior of the Growth and Nucleation Surfaces of Micro- and Nanocrystalline Diamond Films.
B-doped diamond has become the ultimate material for applications in the field of microelectromechanical systems (MEMS), which require both highly wear resistant and electrically conductive diamond films and microstructures. Despite the extensive research of the tribological properties of undoped diamond, to date there is very limited knowledge of the wear properties of highly B-doped diamond. Therefore, in this work a comprehensive investigation of the wear behavior of highly B-doped diamond is presented. Reciprocating sliding tests are performed on micro- and nanocrystalline diamond (MCD, NCD) films with varying B-doping levels and thicknesses. We demonstrate a linear dependency of the wear rate of the different diamond films with the B-doping level. Specifically, the wear rate increases by a factor of 3 between NCD films with 0.6 and 2.8 at. % B-doping levels. This increase in the wear rate can be linked to a 50% decrease in both hardness and elastic modulus of the highly B-doped NCD films, as determined by nanoindentation measurements. Moreover, we show that fine-grained diamond films are more prone to wear. Particularly, NCD films with a 3× smaller grain size but similar B-doping levels exhibit a double wear rate, indicating the crucial role of the grain size on the diamond film wear behavior. On the other hand, MCD films are the most wear-resistant films due to their larger grains and lower B-doping levels. We propose a graphical scheme of the wear behavior which involves planarization and mechanochemically driven amorphization of the surface to describe the wear mechanism of B-doped diamond films. Finally, the wear behavior of the nucleation surface of NCD films is investigated for the first time. In particular, the nucleation surface is shown to be susceptible to higher wear compared to the growth surface due to its higher grain boundary line density.
Department of Precision and Microsystems Engineering, Research Group of Micro and Nano Engineering, Delft University of Technology , Mekelweg 2, 2628 CD Delft, The Netherlands.|Department of Materials Engineering, KU Leuven , Kasteelpark Arenberg 44, B-3001 Leuven, Belgium.
Josephus G
JG
Buijnsters
Department of Precision and Microsystems Engineering, Research Group of Micro and Nano Engineering, Delft University of Technology , Mekelweg 2, 2628 CD Delft, The Netherlands.|Imec , Kapeldreef 75, B-3001 Leuven, Belgium.|IKS-Department of Physics, KU Leuven , Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Menelaos
M
Tsigkourakos
Imec , Kapeldreef 75, B-3001 Leuven, Belgium.
Thomas
T
Hantschel
Imec , Kapeldreef 75, B-3001 Leuven, Belgium.|IKS-Department of Physics, KU Leuven , Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Francis O V
FO
Gomes
Imec , Kapeldreef 75, B-3001 Leuven, Belgium.
Thomas
T
Nuytten
Imec , Kapeldreef 75, B-3001 Leuven, Belgium.
Paola
P
Favia
Imec , Kapeldreef 75, B-3001 Leuven, Belgium.
Hugo
H
Bender
Imec , Kapeldreef 75, B-3001 Leuven, Belgium.|Department of Physics, University of Jyväskylä , P.O. Box 35, FI-40014 Jyväskylä, Finland.
Kai
K
Arstila
Department of Materials Engineering, KU Leuven , Kasteelpark Arenberg 44, B-3001 Leuven, Belgium.
Jean-Pierre
JP
Celis
Imec , Kapeldreef 75, B-3001 Leuven, Belgium.|IKS-Department of Physics, KU Leuven , Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Wilfried
W
Vandervorst
boron doping; diamond films; nucleation surface; planarization; reciprocating sliding; wear