ICMCTF2011 Session E3-1: Tribology of Nanostructured and Amorphous Films

Monday, May 2, 2011 10:00 AM in Room California

Monday Morning

Time Period MoM Sessions | Abstract Timeline | Topic E Sessions | Time Periods | Topics | ICMCTF2011 Schedule

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10:00 AM E3-1-1 Influence of Nanocrystalline Diamond Concentration on DLC Tribomechanical Characterizations
Vladimir Trava-Airoldi, Fernanda Marciano, Polyana Radi, Deiler Lima-Oliveira, Evaldo Corat (Instituto Nacional de Pesquisas Espaciais - INPE, Brazil)
The production of diamond-like carbon (DLC) films with nanocrystalline diamond (NCD) particles incorporated in their structure was for the first time developed in our research group. Our previous studies showed NCD-DLC films improve DLC and stainless steel electrochemical corrosion resistance, preventing aggressive ions from attacking metallic surfaces and becoming a potential candidate for an anti-corrosion material in industrial applications. After, the tribological behavior of these films was investigated under environment air and aggressive solution (NaCl) . NCD particles demonstrated to reduce DLC friction and wear even in aggressive environment. In the present paper, the influence of nanocrystalline diamond concentration in DLC films was investigated regarding the tribomechanical properties. The NCD-DLC films with different NCD concentration were deposited on titanium alloy (Ti6Al4V) samples by DC-pulsed plasma enhanced chemical vapor deposition. The tribological tests were performed in high vaccum in a wide range load and sliding speed. The response surface methodology was used to develop a mathematical modeling of friction and wear of these films, by using the experimental results, in order to identify the parameters that control friction and wear and to obtain the equation that describes these parameters to construct tribologic maps. Scratching tests and nanohardness were also used to characterize the films.
10:20 AM E3-1-2 Effect of Diamond Nanoparticles Addition and Test Conditions on Tribological DLC Films Properties for Space Applications
Polyana Radi, Fernanda Marciano, Deiler Lima-Oliveira, Evaldo Corat, Vladimir Trava-Airoldi (Instituto Nacional de Pesquisas Espaciais - INPE, Brazil); Lucia Santos (Technological Institute of Aeronautics, Brazil)

Nanoparticles addition in DLC films can improve tribomechanical properties and produce adaptive coatings that change their tribological behaviour according environmental atmosphere [1]. Usual experimental approach to study material behaviour to vary one parameter at time while keeping the others constant, thus measuring influence of each variable. This approach requires more experimentation, ignores the interactions between the parameters and can lead to wrong conclusions. Two level factorial design (2-LFD) was used to describe overall effect when you vary all parameters at the same time allows representing the parameters influence in a simple way[2]. This paper presents the use of 2-LFD to study the effect of diamond nanoparticles addition and test conditions (environment, sliding speed and applied load) on tribological behaviour of DLC thin films. Tribological tests were performed in high vacuum and in environment air on rotational mode and in a wide range of load and sliding speed. Scratching tests was also used to study the effect of diamond nanoparticles addition on DLC films. Raman spectroscopy and images of worn surfaces was also used to characterize the films and wear debris.

10:40 AM E3-1-3 The Influence of Bilayer Period and Thickness Ratio on the Mechanical and Tribological Properties of CrSiN/TiAlN Multilayer Coatings
Meng-Ko Wu (Tungnan University, Taiwan); Jyh-Wei Lee (Mingchi University of Technology, Taiwan); Jen-Ching Huang (Tungnan University, Taiwan); Hsien-Wei Chen, Yu-Chen Chan, Jenq-Gong Duh (National Tsing Hua University, Taiwan)
Nanostructured CrSiN/TiAlN multilayer coatings were deposited periodically by a bipolar asymmetric reactive pulsed DC magnetron sputtering system. The thickness ratio of CrSiN to TiAlN layers was fixed at 1:1. The bilayer periods of coatings were controlled ranging from 6 to 40 nm. On the other hand, several CrSiN/TiAlN multilayer coatings with same bilayer period (20nm) and different CrSiN/TiAlN thickness ratios were also deposited to explore the influence of thickness ratio on the mechanical properties of multilayer coatings. The crystalline structures of coatings were determined by a glancing angle X-ray diffractometer. Microstructures of thin films were examined by scanning electron microscopy and transmission electron microscopy, respectively. A nanoindenter, micro Vickers hardness tester, scratch tester and pin-on-disk wear tester were used to evaluate the hardness, toughness, adhesion and tribological properties of thin films, respectively. It was concluded that the maximum hardness was obtained when the bilayer period was around 10~15 nm. Meanwhile, the thickness ratio of CrSiN to TiAlN layer had great influence on the hardness, toughness and tribological properties of multilayer coatings.
11:00 AM E3-1-4 Microstructure, Scratch and Wear Behavior in Thick Ti-Si-C-N and Ti-Al-V-Si-C-N Nanocomposites
Yu-Chen Chan, Hsien-Wei Chen (National Tsing Hua University, Taiwan); Ronghua Wei (Southwest Research Institute); Jenq-Gong Duh (National Tsing Hua University, Taiwan); Jyh-Wei Lee (Mingchi University of Technology, Taiwan)
Thick Ti-Si-C-N and Ti-Al-V-Si-C-N nanocomposites were fabricated by plasma enhanced magnetron sputtering. Characterizations by EPMA, XRD, TEM and SEM revealed the dependence for films with various deposition conditions on the composition, texture and microstructure transformation in coatings. Nanocrystalline Ti(C, N) and Ti-Al-V(C, N) with B1 structure embedded in an amorphous SiCxNy matrix, and such spinodal phase segregation ameliorated the hardness, H/E ratio and tribological properties. It was found that the damage and failure resistance were greatly different in Ti-Si-C-N and Ti-Al-V-Si-C-N, depending on the gradients of loading curve in the nanoidentation. In the micro-scratch and ball-on-disc wear tests, the observation of friction coefficient, worn surfaces and cross-sectional worn scars verified that thick nanocomposites exhibited remarkable tribological resistance. Hybrid anti-wear mechanism on the basis of hardness variation, composition contribution and microstructure evolution was proposed to elucidate the favorable durability of these thick nanocomposites.
11:20 AM E3-1-5 Design and Deposition of Amorphous Carbon Nanocomposite Coatings for Tribological Application
Takanori Takeno (Tohoku University, Japan); Julien Fontaine (Ecole Centrale de Lyon - LTDS, France); Minoru Goto (Ube National College of Technology, Japan); Kosuke Ito (Nihon University, Japan); Hiroyuki Miki, Koshi Adachi (Tohoku University, Japan); Michel Belin (Ecole Centrale de Lyon - LTDS, France); Toshiyuki Takagi (Tohoku University, Japan)

Diamond-like Carbon (DLC) coatings show excellent properties such as high hardness, low friction and low wear, which expand the wide range of their applications. However, there are some disadvantages. Especially, tribological behavior of DLC coatings is highly sensitive to environment and strongly influenced by contact pressure. These materials also exhibit very poor electrical conductivity. These drawbacks can sometimes cause problems for industrial applications. To address such issues, we have focused our attention on nanocomposite DLC coatings, in order to modify surface properties and provide new functionalities. For instance, electrical conductivity can be drastically improved by inclusion of metallic elements/clusters into the DLC coating. We have developed a combined vacuum process composed of plasma enhanced chemical vapor deposition (PECVD) and DC magnetron sputtering devices. Main parameters for the deposition are: gas mixture ratio of the hydrocarbon precursor and argon (controlling the DLC phase growth); and DC sputtering power (controlling additional phase growth). Thanks to the independent and adjustable parameters of CVD and sputtering, various types of nanocomposite coatings with different micro/nano-structures can be fabricated. Based on electron micrographs, structural changes of the coatings are presented depending on the gas mixture ratio of hydrocarbon precursor and argon. Tribological behavior of such coatings is of high interest, since it appears to be quite insensitive to environment (ambient air or ultra-high vacuum) or to normal load. Such results can be discussed in a viewpoint of shearing force of the material transferred from the coating to the counterface. Finally, we discuss “how to design nanocomposite coatings” as a strategic concept to achieve a desired performance.

12:00 PM E3-1-7 Improvement in the Resistance to Corrosion and Tribo-Corrosion of 301 Stainless Steel and Ti-6Al-4V Substrates Induced by Silicon-Based Multilayer Coatings
Duanjie Li, Srinivasan Guruvenket, Salim Hassani, Marwan Azzi (Ecole Polytechnique de Montreal, Canada); Jerzy Szpunar (McGill University, Canada); Jolanta Klemberg-Sapieha, Ludvik Martinu (Ecole Polytechnique de Montreal, Canada)

Amorphous hydrogenated silicon-based multilayer coatings were deposited on 301 stainless steel (SS301) and Ti-6Al-4V alloy substrates using plasma enhanced chemical vapor deposition (PECVD), in order to integrate the advantages of the respective layers. Corrosion and tribo-corrosion behavior of the complete coating/substrate system on different substrates was investigated. The SiN/SiC double layer coating substantially improved the corrosion resistance of the metals: For SS301, the corrosion current, icorr, was reduced by more than three orders of magnitude, and the breakdown voltage was increased from 0.34 to 1.37 V. For Ti-6Al-4V, the icorr was decreased by a factor of ~50. Particularly, the Ti-6Al-4V/SiN/SiC multilayer system exhibited excellent anti-corrosion properties according to potentiodynamic polarization measurements, due to the superior corrosion resistance of both the Ti-6Al-4V substrate and the silicon-based coatings. Further enhancement of the tribo-corrosion resistance has been achieved by applying an a-C coating as a top layer in the three-layer system. In the tribo-corrosion test in 1 wt.% NaCl solution, the SiN/SiC/a-C coating reduced the wear rate and the friction coefficient by a factor of ~175 and ~4, respectively, compared with the bare Ti-6Al-4V. The Ti-6Al-4V/SiN/SiC/a-C multilayer system integrates in synergy the advantages of the respective layers, and its versatility makes it a particularly attractive candidate for applications in different harsh working environments.

Time Period MoM Sessions | Abstract Timeline | Topic E Sessions | Time Periods | Topics | ICMCTF2011 Schedule