111 documents found, page 1 of 12
Effect of peak power on microstructure, mechanical and tribological properties ...
Ataie, S.A.; Soltanieh, M.; Naghizadeh, R.; Cavaleiro, A.; Fernandes, F.; Ferreira, F.This research investigates the impact of peak power (from 44 to 105 kW) on the structural and tribological properties of W-Ti-C-N(O) films. Chemical analysis of the coatings, using energy-dispersive spectroscopy and Raman spectroscopy, indicates that increasing target power results in a rise in the oxygen (from 2.6 to 12.0 at%), carbon (from 19.7 to 32.4 at%), and sp3 (from 9.8% to 24.3%) content. Morphological...
The role of interfaces and morphology on silver diffusion in hard coatings
Cavaleiro, D.; Munnik, F.; Krause, M.; Carbo-Argibay, E.; Ferreira, P.J.; Cavaleiro, A.; Fernandes, F.One of the main approaches to increase the tool lifetime during dry machining of “hard-to-machine” aerospace alloys is self-lubrication by the incorporation of noble metals in hard matrixes with good mechanical and diffusion barrier properties. In this paper, the diffusion of an Ag-rich layer sandwiched between two layers of either TiN or TiSiN is studied by transmission electron microscopy and in situ Rutherfo...
Effect of substrate bias voltage on structural and tribological properties of W...
Ataie, S.A.; Soltanieh, M.; Naghizadeh, R.; Cavaleiro, A.; Evaristo, M.; Fernandes, F.; Ferreira, F.Protective multi-component thin films at the surface of cutting tools have been significantly developed to reduce wear and friction. The present work investigates the effect of substrate bias voltage on the structural-tribological relations of W-Ti-C-N thin films produced by HiPIMS and DCMS co-sputtering. Chemical analysis of the coatings is obtained and composite phase structure is revealed. Morphology of the ...
The influence of V addition on the structure, mechanical properties, and oxidat...
AL-Rjoub, A.; Yaqub, Talha Bin; Cavaleiro, A.; Fernandes, FilipeThe influence of V content on the morphology, structure, hardness (H) and reduced Young's modulus (E), adhesion, and oxidation resistance of TiAlSiN coatings is investigated. The coatings were produced by DC reactive magnetron sputtering, with increasing V contents from 0, 4.8 and 11.0 at.%. All coatings exhibit a fcc type structure. The coating with 4.8 at.% of V shows the highest values of H and E, whereas th...
Room and high temperature tribological performance of CrAlN(Ag) coatings: The i...
Rajput, S.S.; Gangopadhyay, S.; Yaqub, T.B.; Cavaleiro, A.; Fernandes, FilipeThe present study aims to investigate the effect of the addition of Ag on the tribological performance of a CrAlN coating system, at room and high temperatures (600 °C). The addition of Ag, in general, has been seen beneficial in lowering the coefficient of friction (COF) at room and high temperatures. Independent of the decrease of COF with Ag additions, the specific wear rate was degraded. The only exception ...
Influence of Ag additions on the structure, mechanical properties and oxidation...
Rajput, S.S.; Gangopadhyay, S.; Cavaleiro, A.; AL-Rjoub, A.; Kumar, Ch. Sateesh; Fernandes, F.In this work, the influence of Ag additions into CrAlN coatings on the surface morphology, chemical composition, structure, hardness and oxidation behaviour was studied. Increasing the Ag content decreased the size of the morphological features and produced a more compact coatings. All coatings displayed a fcc structure typical of transition metal nitrides; the silver phase was indexed for the coatings with Ag ...
High Si multilayered TiSiN/TiN(Ag) films with superior oxidation resistance
Al-Rjoub, A.; Cavaleiro, A.; Rajput, S. S.; Fernandes, F.In this work, the effect of Ag content on the morphology, structure, mechanical properties, thermal stability, and oxidation resistance of multilayered TiSiN/TiN(Ag) films, with Si concentration in the range of 6.3e7.0 at.%, is investigated. The coatings are deposited by DC reactive magnetron sputtering, with increasing Ag content from 0 to 13.9 at.%. All coatings exhibit a face-centered cubic structure (f.c.c ...
Galvanic oxidation of bimetallic Zn-Fe nanoparticles for oxygen scavenging
Castro, A.; Carvalho, I.; Marques, L.; Ferreira, P. J.; Cavaleiro, A.; Carvalho, S.; Velasco, Sebastian CalderonBimetallic nanoparticles (NP) have demonstrated outstanding multifunctional characteristics, which depend on their size, distribution and composition. In this study, we show the possibility of tailoring the oxidation behavior of Zn-Fe bimetallic nanoparticles produced by magnetron sputtering and gas agglomeration system. Zn and Fe metals were coupled to promote faster oxidation of Zn, stimulating a galvanic mec...
Influence of Ag alloying on the morphology, structure, mechanical properties, t...
Al-Rjoub, A.; Cavaleiro, A.; Fernandes, F.Self-lubricant films combine the intrinsic properties of high oxidation resistance coatings with lubricious elements deposited as monolayer and/or multilayered configuration, offering an opportunity to design green coating materials. The present paper reports the influence of Ag additions (range 0–3.2 at.%), considered as low friction material, on the morphology, structure, mechanical properties, thermal stabil...
An experimental and theoretical study on the crystal structure and elastic prop...
Almeida Alves, C. F.; Marques, L.; Calderon, S. V.; Ferreira, P. J.; Schneider, D.; Cavaleiro, A.; Carvalho, S.The production of Ta1-xOx coatings has attracted a lot of attention due to their wide variety of industrial applications. Nonetheless, to properly control the functional properties of these coatings, a good understanding of their structural properties must be achieved. Ta1-xOx phases have structural similarities since they are formed by the distortion of the body centered cubic (bcc) Ta structure and, therefore...