ICMCTF2016 Session B4-2: Properties and Characterization of Hard Coatings and Surfaces

Thursday, April 28, 2016 8:20 AM in Room San Diego

Thursday Morning

Time Period ThM Sessions | Abstract Timeline | Topic B Sessions | Time Periods | Topics | ICMCTF2016 Schedule

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8:20 AM B4-2-2 Mechanical and Tribological Properties of Diamond Like Carbon Coating Deposited by Round Bar Type Carbon Cathodic Arc Source
Shinichi Tanifuji, Satoshi Hirota, Hirofumi Fuji, Jun Munemasa, Koichiro Akari (Kobe Steel Ltd., Japan)
Among the deposition process for DLC(diamond like carbon), cathodic arc process has become a popular process and has been used especially for depositing ta-C films on many kinds of automotive components. But in the arc discharge of carbon target, arc spot movement is slower than other metal targets and the discharge is not even on the target surface. So the production scale equipment has still problem about the stability of carbon arc source. To improve this problem, new arc source for carbon discharge was developed, so it was reported that the new arc source made it possible to be stable dicharge, deposit smooth ta-C coating, and be simple system configuration in ICMCTF2015. In this report, mechanical and tribological properties of thick arc DLC coating deposited by the new arc source will be reported.
8:40 AM B4-2-3 Effect of Titanium Doping in the Structure, Intrinsec Stress and Mechanical Properties of WS2 Thin Films
JuanManuel Gonzalez, Carolina Portilla (Universidad Del valle, Colombia); Johans Restrepo, Stephen Muhl (Universidad Nacional Autonoma de Mexico, Mexico); Federico Sequeda (Universidad Del valle, Colombia)

Titanium doped tungsten disulphide thin films were deposited using magnetron sputtering, varying the Ti percentage from 0 to 40% in order to observe the influence of the Ti doping on the crystalline structure, superficial, mechanical properties. X-ray diffraction showed a critical super saturation Ti percentage between 20 to 30% with an amorphous WS2 phase and low dimensional Ti segregation in the structure. Different amounts of Ti doped films (0, 10 and 40%) presented typical hexagonal structure of the WS2, however Ti segregation was observed as only low intensity peaks were observed for the 40% Ti doped. Profilometry showed an average thickness of 1.5 μm and intrinsic stress, obtained by the Stoney model, showed a compressive stress decreasing with the increase of Ti%. This effect is produced by segregation of Ti to the grain boundary. Subsequently the effect of different loads in the mechanical properties of the films were studied using instrumented nanoindentation, generating a hardness, elastic moduly and plastic deformation profiles, determining the influence of the substrate on the mechanical properties of the films using the Korsunsky model and evaluating the indentation impression using scanning electron microscopy. The generation of radial cracks was observed, which were associated to delamination and adhesive failures. This procedure allowed the estimation of the adhesion critical load and to determinate the fracture tenacity behavior in the thin film. In addition, the contact stress profile was observed from the Hertzian contact model, using the hardness and the elastic moduli obtained from the Oliver and Pharr model.

9:00 AM B4-2-4 Effect of Interlayer on Wear Resistance and Mechanical Properties of Thick TiZrN Coating on D2 Steel Deposited by Unbalanced Magnetron Sputtering
Wei-Ren Cheng, Ge-Ping Yu, Jia-Hong Huang (National Tsing Hua University, Taiwan, Republic of China)

The objective of this study was to deposit thick TiZrN coatings on Ti interlayer above 3μm on AISI D2 steel by dc unbalanced magnetron sputtering, performances of the coating were compared with TiZrN coatings without Ti interlayer. In our previous study, both TiN and ZrN coatings were deposited on AISI D2 steel with thickness above 6 m and excellent properties such as hardness, fracture toughness, and low electric resistivity. Compared with TiN or ZrN, TiZrN not only retained low resistivity and warm golden color but also possessed more superior mechanical properties and better corrosion resistance. Compositions of TiXZr1-XN might presented different property, so it was obviously to select one of the composition which possessed higher hardness and fracture toughness. Interlayer also played an important role in the films. Introducing Ti interlayer could improve the films adhesion and corrosion resistance; and release the residual stress of the films which limited films thickness. TiZrN and TiZrN /Ti coatings were prepared. The hardness, adhesion strength and wear resistance were assessed by nano-indentation, scratch test and pin-on-disk test, respectively. The residual stress in the coating was determined by both cos2αsin2ψ X-ray diffraction, and crystal structure was studied by XRD. Microstructure was observed by SEM which correlated to the deposition parameters and coatings properties. Roughness was measured by AFM which also affected coating’s wear rate and adhesion. Based on our approach, we can develop a promising deposition process, which can produce TiZrN/ Ti thick coatings with excellent mechanical properties.

9:20 AM B4-2-5 Tribological Properties and Tribo-Tests from the Industrial Perspective
Nazlim Bagcivan, Edgar Schulz, Walter Holweger, Yashar Musayev, Tim Hosenfeldt (Schaeffler Technologies AG & Co. KG, Germany)
One of the key challenges considering global warming is the reduction of CO2-Emissions. In view of the fact that transportation contributes considerably to CO2-Emissions measures for reduction of emissions are among main development goals. Besides other measures improvement of tribological conditions along the drive chain of passenger cars and commercial vehicles provide a high saving potential regarding emissions. A sustainable reduction of CO2-emission by friction reduction is only achievable if friction reduction is ensured during the whole lifetime of the coated products. Therefore the development goal can be summarized as “minimum friction at highest wear resistance”. For innovative products, it is extremely important to consider coatings as design elements and integrate them in the product development process at a very early stage. In this presentation an overview about the integration of tribological tests into the design process is given. On the one hand tribometers are known to be too simple to fully rebuild application conditions and can only give limited information about tribological behavior. On the other hand they offer a very good controllability of test conditions and can provide fundamental information very cost-effectively. For, fired engine tests are expensive and have to be the final evaluation step for selected coating candidates. For a successful product development a close collaboration between designers and surface engineers is one of the core competences at Schaeffler Group. The Schaeffler Group delivered more than 100 million high-quality PVD- and (PA)CVD-coated components for automotive and industrial division every year which enables outstanding applications, preserve resources and meet increasing customer requirements. As a result, customers benefit from all over the world and receive innovative, customized solutions of highest quality.
10:00 AM B4-2-7 WEAR Resistance of PIRAC Nitrogen-Diffusion Treated and DUPLEX-Hybrid PAPVD-Coated Ti-6Al-4V Alloy
Thelma Bonello (University of Malta, Malta); JuniaCristina Avelar-Batista Wilson, Jonathan Housden (Wallwork Cambridge Ltd., UK); Elazar Gutmanas, Irena Gotman (Technion IIT, UK); Allan Matthews, Adrian Leyland (University of Sheffield, UK); Glenn Cassar (University of Malta, Malta)

This study evaluates wear properties of PIRAC nitrogen-diffusion treatment, single and multilayered plasma-assisted physical vapour deposition (PAPVD) Ti/TiN-coated and duplex-hybrid PIRAC nitrogen-diffusion treated/PVD-coated Ti-6Al-4V. Nanoscratch testing shows that surface layer failure (at the maximum normal critical load of 450 mN) was observed only for TiN deposited on untreated Ti-6Al-4V - characterised by large instances of delamination - and for the PIRAC nitrogen-diffusion treated alloy. The compound layer formed in the latter is not able to support the indenter passage consequently resulting in tensile fracture and exposure of the underlying bulk metal . Finally, the results presented here show that an appropriate sequential PIRAC nitrogen-diffusion pretreatment (at 800 ˚C for 4 h) in combination with a Ti/TiN multilayered metal/ceramic coating provides superior tribological performance when compared to either PIRAC nitrogen-diffusion alone, PAPVD coated-only substrates or the untreated Ti-alloy substrate.

10:20 AM B4-2-8 CVD Diamond Coating on WC-Co Substrate with Al-based Interlayer
Fan Ye, Yuanshi Li, Qiaoqin Yang (University of Saskatchewan, Canada); Chang-Yong Kim (Canadian Light Source Inc., Canada)

Diamond coating with sufficient adhesion on WC-Co cutting tools is expected to significantly increase their cutting performance. In order to enhance the coating-substrate interfacial adhesion, Al2O3 and Ta mono-interlayer, Al-Al2O3, Al-AlN and Al-Ta duplex interlayer systems have been developed in this study. These interlayer materials were prepared using a magnetron sputtering method, and diamond coating were deposited on them using microwave plasma enhanced chemical vapor deposition. Grazing incident X-ray diffraction was carried out to determine the phase components in the Al-Al2O3 and Al-AlN interlayers. Raman spectroscopy and scanning electron microscopy were used to evaluate the quality, morphology and microstructure of the deposited diamond coatings. Rockwell C indentation testing was performed to evaluate the adhesion of the coatings. To elucidate the coating failure mechanism, the compositions around the delaminated spots of diamond coatings after indentation were identified by Energy-dispersive X-ray spectroscopy. The results show that continuous diamond coatings were achieved on Al2O3, Al-Al2O3, Al-AlN and Al-Ta interlayered substrates, whereas a graphite layer was still formed with the Ta monolayer, accompanied by an easy spallation of diamond coatings. The Al interlayer has played an important role in obtaining high purity diamond by in-situ forming an alumina barrier layer. Especially, the diamond coating deposited with an Al-AlN interlayer demonstrates superior interfacial adhesion in comparison with all the other interlayers.

Time Period ThM Sessions | Abstract Timeline | Topic B Sessions | Time Periods | Topics | ICMCTF2016 Schedule