scholarly journals Protective Sliding Carbon-Based Nanolayers Prepared by Argon or Nitrogen Ion-Beam Assisted Deposition on Ti6Al4V Alloy

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Petr Vlcak ◽  
Ivan Jirka

The microstructure and the surface properties of samples coated by carbon-based nanolayer were investigated in an effort to increase the surface hardness and reduce the coefficient of friction of the Ti6Al4V alloy. Protective carbon-based nanolayers were fabricated by argon or nitrogen ion-beam assisted deposition at ion energy of 700 eV on Ti6Al4V substrates. The Raman spectra indicated that nanolayers had a diamond-like carbon character with sp2rich bonds. The TiC and TiN compounds formed in the surface area were detected by X-ray diffraction. Nanoscratch tests showed increased adhesion of a carbon-based nanolayer deposited with ion assistance in comparison with a carbon nanolayer deposited without ion assistance. The results showed that argon ion assistance leads to greater nanohardness than a sample coated by a carbon-based nanolayer with nitrogen ion assistance. A more than twofold increase in nanohardness and a more than fivefold decrease in the coefficient of friction were obtained for samples coated by a carbon-based nanolayer with ion assistance, in comparison with the reference sample.

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Tomas Horazdovsky ◽  
Radka Vrbova

This paper presents the tribomechanical test results of Ti6Al4V alloy modified by carbon-based nanolayers with a thickness of 20 nm and 40 nm, prepared by nitrogen ion beam assisted deposition. The presence of carbon and nitrogen compounds was observed in the modified surface after ion bombardment. Nonstoichiometric TiNx was mainly detected near the interface nanolayer/titanium substrate and in the substrate itself. Ion bombardment led to an improved surface hardness of ~13 GPa in comparison to unmodified Ti6Al4V titanium alloy (~5.5 GPa) and alloy coated by carbon nanolayer without nitrogen ion assistance (~7 GPa). The decreasing of friction coefficient was achieved from 0.5–0.6 for untreated Ti6Al4V alloy to 0.1 for treated Ti6Al4V alloy. Wear testing using a joint wear simulator proved that the modified Ti6Al4V alloy has a higher resistance compared to the unmodified Ti6Al4V alloy. The primary local wear fault of the treated surface was observed after 240,000 cycles in comparison to enormous wear on the untreated surface after just 10,000 cycles. Treating the Ti6Al4V load-bearing components of implants with carbon-based nanolayers assisted by nitrogen ions is very promising in terms of extending the lifetime of implants and thereby reduces patient burden.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Petr Vlcak ◽  
Frantisek Cerny ◽  
Zdenek Weiss ◽  
Stanislav Danis ◽  
Josef Sepitka ◽  
...  

The ion beam assisted deposition (IBAD) method was chosen for preparing a carbon thin film with a mixing area on a substrate of Ti6Al4V titanium alloy. Nitrogen ions with energy 90 keV were used. These form a broad ion beam mixing area at the interface between the carbon film and the substrate. We investigated the chemical composition by the glow discharge optical emission spectroscopy (GD-OES) method and the phases by the X-ray diffraction (XRD) method. The measured concentration profiles indicate the mixing of the carbon film into the substrate, which may have an effect on increasing the adhesion of the deposited film. The nanohardness and the coefficient of friction were measured. We found that the modified samples had a markedly lower coefficient of friction even after damage to the carbon film, and they also had higher nanohardness than the unmodified samples. The increased nanohardness is attributed to the newly created phases that arose with ion implantation of nitrogen ions.


2003 ◽  
Vol 125 (3) ◽  
pp. 661-669 ◽  
Author(s):  
Masaya Kurokawa ◽  
Yoshitaka Uchiyama ◽  
Tomoaki Iwai ◽  
Susumu Nagai

Tribological properties of several kinds of polyoxymethylene (POM) composites were evaluated for the purpose of developing a polymeric tribomaterial especially suited for mating with aluminum parts having low surface hardness. POM composites containing small amounts of silicon carbide (SiC), POM/SiC; those containing a small amount of calcium octacosanonoate besides SiC, POM/SiC/Ca-OCA; and the one blended with 24 wt % of polytetrafluoroethylene, POM/PTFE(24); were injection-molded into pin specimens and their tribological properties were tested by means of a pin-on-disk type wear apparatus using an aluminum (A5056) mating disk in comparison with a 303 stainless steel (SUS303) disk. Evaluation was focused on observation of the sliding surfaces of the pin specimens and the mating disks by a scanning electron microscope and an optical microscope together with the measurement of surface roughness. In the case of mating against a SUS303 disk having high surface hardness, all pin specimens did not roughen the disk surfaces even after long time of rubbing. Only POM/PTFE(24) composite obviously made a transfer film on the disk surface, while the other composites made an extremely thin one on it. POM/SiC(0.1)/Ca-OCA(1) composite, containing SiC 0.1 wt. % and Ca-OCA 1 wt. %, was found to show the lowest coefficient of friction and the lowest wear rate forming extremely thin transfer film on the mating disk. On the other hand, against an A5056 disk which has lower surface hardness than that of SUS303 disk, unfilled POM and POM composites except POM/SiC(0.1)/Ca-OCA(1) composite roughened the disk surfaces. However, the sliding surface of the A5056 disk rubbed with POM/SiC(0.1)/Ca-OCA(1) composite was significantly smoother and that of the pin specimen was also quite smooth in comparison with other pin specimens. Further, when each POM composite was rubbed against the A5056 disk, formation of transfer film was not obvious on the disk surfaces. For POM/SiC(0.1)/Ca-OCA(1) composite, the wear rate was the lowest of all POM composites, and the coefficient of friction was as low level as 60 percent of that of unfilled POM, but slightly higher than that of POM/PTFE(24) composite. For POM/SiC(0.1)/Ca-OCA(1) composite, the nucleating effect of SiC and Ca-OCA, which accelerated the crystallization of POM during its injection molding to form a matrix containing fine spherulites, must have resulted in increasing the toughness of the matrix and lowering the wear rate. Also, the lubricant effect of Ca-OCA should have lowered the coefficient of friction of the same matrix for rubbing against aluminum mating disk. POM/SiC(0.1)/Ca-OCA(1) composite was concluded as an excellent tribomaterial for mating with aluminum parts.


2021 ◽  
Vol 1032 ◽  
pp. 163-171
Author(s):  
Jing Guan ◽  
Xue Ting Jiang ◽  
Xing Cheng ◽  
Feng Yang ◽  
Jing Liu

The surface of Ti6Al4V alloy was rapidly carburized by high-frequency electromagnetic induction heating under vacuum. The microstructure and hardness of the carburized layer were studied. The wear properties of the carburized layer were tested at 50, 100 and 200 rpm using the end face friction and wear device, and the wear mechanism was analyzed. The results show that the TiC strengthening phase was formed on the surface of Ti6Al4V alloy after high-frequency induction carburization, and the surface grains were refined. The surface hardness reaches 1116 HV0.25, but the brittleness of the carburized layer increases with increasing temperature. The amount of wear was reduced by 54% at 100 rpm. The roughness of the wear scar was reduced from 3.26 μm to 2.28 μm of Ti6A14V alloy matrix. The coefficient of friction and wear rate increases with increasing speed. The wear mechanism was transformed from adhesive wear and oxidative wear of the substrate to abrasive wear after carburizing.


Author(s):  
H.-S. Zhang ◽  
K. Komvopoulos

Silicon wafers were exposed to an oblique Ar+ ion beam to create arrays of surface ripples. Atomic force microscope (AFM) imaging revealed that the rippled (textured) surfaces exhibited highly anisotropic morphologies. Nanoscale friction experiments performed with different diamond tips illustrated a dependence of the coefficient of friction on tip radius, normal load, and sliding direction. Changes in the coefficient of friction are interpreted in terms of the applied normal load and varying contributions of the adhesion friction mechanism.


Vacuum ◽  
2003 ◽  
Vol 70 (2-3) ◽  
pp. 411-416 ◽  
Author(s):  
P. Budzynski ◽  
P. Tarkowski ◽  
P. Żukowski ◽  
K. Kiszczak ◽  
W. Kasietczuk

2001 ◽  
Vol 695 ◽  
Author(s):  
Shuichi Miyabe ◽  
Masami Aono ◽  
Nobuaki Kitazawa ◽  
Yoshihisa Watanabe

ABSTRACTAluminum nitride (AlN) thin films with columnar and granular structures were prepared by ion-beam assisted deposition method by changing nitrogen ion beam energy, and the effects of the film microstructure and film thickness on their microhardness were studied by using a nano-indentation system with the maximum force of 3 mN. For the columnar structure film of 600 nm in thickness, the microhardness is found to be approximately 24 GPa when the normalized penetration depth to the film thickness is about 0.1. For the granular structure film of 700 nm in thickness, the microhardness is found to be approximately 14 GPa. These results reveal that the microhardness of the AlN films strongly depends on the film microstructure, which can be controlled by regulating the nitrogen ion beam energy.


1988 ◽  
Vol 128 ◽  
Author(s):  
E. P. Donovan ◽  
C. A. Carosella ◽  
D. Van Vechten

ABSTRACTThe annealing behavior of the optical properties of silicon nitride films (Si1-xNx) is described for films fabricated by ion beam assisted deposition. The data are needed for the precise manufacture of optical filters, where the index of refraction must be predicted from deposition parameters and film annealing history.The reflection of homogeneous, amorphous samples deposited on (100) silicon substrates was measured from 500 to 3120 nm. Fits to the interference spectra were obtained over the range 1000 to 3120 nm to obtain the index of refraction vs wavelength as a function of film nitrogen content. Nitrogen atom fraction was varied from.2 to.58 by variation of the incident relative fluxes of nitrogen ion beam current to evaporant silicon flux. The films were annealed in argon at 450 C, 600 C, 750 C, and 1100 C and the measurements repeated. The systematic shifts in index of refraction with annealing temperature are described.


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