Influência das espécies do plasma na modificação das propriedades superficiais do titânio tratado por plasma de N2 - Ar - O2

Abstract

RESUMOO presente estudo mostra uma relação entre o comportamento das espécies ativas do plasma com as propriedades superficiais do titânio. Para tanto, espécies ativas como N 2 + (391,4 nm) e O (844,6 nm) foram analisadas por espectroscopia de emissão óptica (OES) em plasma produzido por uma mistura de gases ABSTRACTThe present study correlates plasma active species with titanium surface properties. This was achieved by performing optical emission spectroscopy (OES) analysis of N 2 + (391.4 nm) and O (844.6 nm) within a N 2 -A r -O 2 plasma. The fluxes of gases were established to be 1 and 4 sccm (standard cubic centimeter) for nitrogen and argon, while that of oxygen was varied between 2 and 4 sccm. A non-linearity of the intensity of N 2 + (391.4 nm) species with the increase on O 2 flux was observed with an intensity peak at 3 sccm. It was also concluded that the active species influence the modification of properties after the plasma treatment. The N 2 + (391.4 nm) species were more effective to form nitrides and the surface roughness was bigger when those species presented higher intensity. Surface hardness and surface stress were also higher whenever using higher intensity fluxes of N 2 + (391.4 nm). Furthermore, while the N 2 + (391.4 nm) specie influenced the dispersive component, the O (844.6 nm) specie influenced the polar component.

Ionic Oxidation in Cathodic Cage of Titanium CP Grade II

“…According to the results of the contact angle, shown in Figure 3 and Figure 4, the tendency of the reduction of the angle of contact with the treatment time can be mentioned as the main point. The result for the untreated sample presented an angle value around 63.00 ± 4.00, presenting a hydrophilic character due to the value being smaller than 90º which is already characteristic of titanium samples with the preparation performed in the present work 12 . The sample with 3 hours of treatment obtained a value of 32.66 ± 2.52 and the sample with 8 hours of treatment 6.33 ± 0.58, observing a considerable decrease of the angle of contact with the treatment time.…”

“…In Figure 2 (a) in the diffractogram, is observed the presence of the anatase, brookite and rutile phases of the sample treated for the angle of 0.5º, being the first and the last one more commonly found in works of the literature. Attention is drawn to the presence of the brookite phase that is formed under specific pressure conditions and lower temperatures, being difficult to produce in conventional thermochemical treatments 12 . This fact proves that superficially, the deposition process was effective, significantly modifying the surface treated sample.…”

“…This change of properties is explained by the overlap between the "2p" orbitals of the interstitial elements such as oxygen, and the titanium d orbitals. In addition, in recent years, several researches have been conducted, mainly due to its biocompatibility and the sensitive modification of its properties, such as friction, optical absorption, hardness, wettability and wear, among others, when interstitial elements such as hydrogen, carbon, nitrogen or oxygen are introduced into their crystalline lattice [11][12][13][14] . This implies the importance of the need to control the composition and structure during the surface processing of titanium.…”

Titanium Surface Chemical Composition Interferes in the Pseudomonas aeruginosa Biofilm Formation

“…A chromel‐alumel thermocouple was placed in contact with the bottom of the sample holder to monitor temperature. The gas flow rate was controlled by digital flow meters (MKS model 247), as detailed in previous work .…”

Titanium Oxynitriding by Plasma-Assisted Thermochemical Treatments Using a Competitive Atmosphere of H2-N2-O2

“…Although numerous experimental and theoretical studies exist for α-Ti(N,O) solid solutions, TiN x O 1-x solid cubic solution (NaCl-type), TiO 2 , and TiN compounds and the conditions for their formation 8,9,12,13,[15][16][17] , there is still a degree of uncertainty regarding the bonding and structure of TiN x O 1-x . Various experimental methods have been employed to synthesize and understand the formation mechanism of TiO x N y [18][19][20][21][22] . The plasma-assisted thermochemical technique is conducted in the abnormal glow discharge region.…”