Manuel Evaristo

Dr. Manuel Evaristo

CEMMPRE—Centre for Mechanical Engennering, Materials and Processes, Department of Mechanical Engeneering, University of Coimbra, Rua Luis Reis Santos, 3030-788 Coimbra, Portugal
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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2015 in Surface and Coatings Technology
Verified
Journal Article
Closed access
PMPetr Mutafov
Petr Mutafov
Manuel EvaristoManuel Evaristo
Manuel Evaristo
ACAndré Cavaleiro
André Cavaleiro
TPTomas Polcar
Tomas Polcar

27 March 2020 in Coatings
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Journal Article
Open access
PDF file
Manuel EvaristoManuel Evaristo
Manuel Evaristo
Filipe FernandesFilipe Fernandes
Filipe Fernandes
ACAndré Cavaleiro
André Cavaleiro
Carbon-based coatings are used in many applications, particularly in sliding contacts to reduce friction and wear. To improve the tribological properties, these coatings are usually alloyed with metals; W is one of the most used since it helps improve the tribological performance at high temperatures. In this work, we compared the tribological performance of Diamond-Like Carbon alloyed with tungsten (DLC-W) films deposited by direct current magnetron sputtering (DCMS) with films deposited in a hybrid configuration DCMS + high power impulse magnetron sputtering (HiPIMS). The DLC-W coatings were produced with approximately the same W content. One hydrogenated film was deposited with the hybrid configuration for comparison purposes. Microstructure, structure, mechanical properties, and tribological behaviour were used to compare the coatings. All the films displayed a low-order structure of tungsten carbide embedded in an amorphous carbon matrix. The use of the hybrid HiPIMS/DCMS results in coatings with more compact morphologies due to the high ionization fraction of the species produced on the W target (W and Ar ionized species), which primarily will oppose the shadowing effect as the ions will reach the substrate at angles close to 90°. HiPIMS non-hydrogenated film is the more tribological, performing either at room or high temperature (150 °C) due to the much more compact morphology, which avoids the detachment of hard W-C particles, which are responsible for more efficiently scratching the film surface. Experiments revealed that wear behaviour in all the films is governed by the contact of the tribolayer formed on the counterpart composed of W–C, C and W–O against the surface of the film.

1 November 2016 in Diamond and Related Materials
Verified
Journal Article
Closed access
Manuel EvaristoManuel Evaristo
Manuel Evaristo
RAR. Azevedo
R. Azevedo
CPC. Palacio
C. Palacio
ACAndré Cavaleiro
André Cavaleiro


1 October 2008 in Acta Materialia
Verified
Journal Article
Closed access
TPT. Polcar
T. Polcar
Manuel EvaristoManuel Evaristo
Manuel Evaristo
Rogerio ColacoRogerio Colaco
Rogerio Colaco
CSC. Silviu Sandu
C. Silviu Sandu
ACAndré Cavaleiro
André Cavaleiro

1 April 2007 in Plasma Processes and Polymers
Verified
Journal Article
Closed access
PDF file
TPTomas Polcar
Tomas Polcar
Manuel EvaristoManuel Evaristo
Manuel Evaristo
ACAndré Cavaleiro
André Cavaleiro