scholarly journals A Strategy for Alleviating Micro Arcing during HiPIMS Deposition of DLC Coatings

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1038
Author(s):  
Catalin Vitelaru ◽  
Anca Constantina Parau ◽  
Lidia Ruxandra Constantin ◽  
Adrian Emil Kiss ◽  
Alina Vladescu ◽  
...  

In this work, we investigate the use of high power impulse magnetron sputtering (HiPIMS) for the deposition of micrometer thick diamond like carbon (DLC) coatings on Si and steel substrates. The adhesion on both types of substrates is ensured with a simple Ti interlayer, while the energy of impinging ions is adjusted by using RF (Radio Frequency) biasing on the substrate at −100 V DC self-bias. Addition of acetylene to the working Ar+Ne atmosphere is investigated as an alternative to Ar sputtering, to improve process stability and coatings quality. Peak current is maintained constant, providing reliable comparison between different deposition conditions used in this study. The main advantages of adding acetylene to the Ar+Ne gas mixture are an increase of deposition rate by a factor of 2, when comparing to the Ar+Ne process. Moreover, a decrease of the number of surface defects, from ~40% surface defects coverage to ~1% is obtained, due to reduced arcing. The mechanical and tribological properties of the deposited DLC films remain comparable for all investigated gas compositions. Nanoindentation hardness of all coatings is in the range of 25 to 30 GPa, friction coefficient is between 0.05 and 0.1 and wear rate is in the range of 0.47 to 0.77 × 10−6 mm3 N−1m−1.

2020 ◽  
pp. 1-28
Author(s):  
Yanyan Wang ◽  
Yang Wang ◽  
Jia-jie Kang ◽  
Guozheng Ma ◽  
Lina Zhu ◽  
...  

Abstract Diamond-like carbon (DLC) coatings containing 0.7%, 5.8% and 23.3% Ti were deposited via pulsed cathodic arc deposition and magnetron sputtering on AISI 316L stainless steel substrates. The varied Ti content was controlled by setting Ti target current at 3, 5 and 7A. The composition, microstructure, mechanical and tribological properties of Ti-doped DLC (Ti-DLC) coatings were investigated using X-ray photoelectron spectroscopy, Raman spectroscopy, nanoindentation and ball-on-disc tribometer. The results show that TiC formed when Ti content in the coating was higher than 5.8% and the ID/IG ratios increased gradually with the increasing Ti content. Ti-DLC with 0.7 Ti had the highest H/E and H3/E2 ratios and exhibited optimal tribological properties under lubrication, especially when ZDDP was contained in the oil. Furthermore, ZDDP tribofilms played an important role in wear reduction by protecting the rubbing surfaces against adhesion and suppressing the tribo-induced graphitization of DLC coatings.


10.14311/398 ◽  
2003 ◽  
Vol 43 (1) ◽  
Author(s):  
D. Palamarchuk ◽  
M. Zoriy ◽  
J. Gurovič ◽  
F. Černý ◽  
S. Konvičková ◽  
...  

DLC (Diamond-Like Carbon) coatings have been suggested as protective surface layers against wear. However hard DLC coatings, especially those of greater thickness, have poor adhesion to substrates. We have used several ways to increase the adhesion of DLC coatings prepared by the PACVD (Plasma Assisted Chemical Vapour Deposition) method on steel substrates. One of these is the DC PACVD method for preparing DLC films.


Lubricants ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 38 ◽  
Author(s):  
Giulia Fiaschi ◽  
Alberto Rota ◽  
Antonio Ballestrazzi ◽  
Diego Marchetto ◽  
Enrico Vezzalini ◽  
...  

Diamond-like carbon is one of the most studied and used solid lubricants on the market. Despite this large use and its outstanding mechanical and tribological properties, there are still some unclear aspects related to its self-lubricant properties, and some drawbacks in the deposition methods. We deposited “soft” DLC films on Si(100), iron, and stainless steel substrates by PVD magnetron sputtering technique with a Cr/CrN adhesive interlayer. The DLC films were characterized from a chemical, mechanical, and tribological point of view. Our aim was to connect the coating chemical and mechanical characteristics to the different conditions used for the deposition, such as discharge power and substrate–target distance. We found a stronger sp3 dependence on the discharge power for DLC deposited closer to the target. The tribological results did not depend on the chosen substrate–target distance, but rather on the hardness of the substrate. This could be ascribed to the better mechanical coupling of soft DLC films on harder substrates.


2016 ◽  
Vol 33 (6) ◽  
pp. 769-776 ◽  
Author(s):  
Y.-R. Jeng ◽  
S. Islam ◽  
K-T. Wu ◽  
A. Erdemir ◽  
O. Eryilmaz

AbstractHydrogenated diamond like Carbon (H-DLC) is a promising lubricious coating that attracted a great deal of interest in recent years mainly because of its outstanding tribological properties. In this study, the nano-mechanical and -tribological properties of a range of H-DLC films were investigated. Specifically, four kinds of H-DLC coatings were produced on Si substrates in pure acetylene, pure methane, 25% methane + 75% hydrogen, 50% methane + 50% hydrogen discharge plasmas using a plasma enhanced chemical vapour deposition (PECVD) system. Nano indentation was performed to measure the mechanical properties such as hardness and young's modulus and nanoscartching was performed to investigate the frictional behavior and wear mechanism of the H-DLC samples in open air. Moreover, Vickers indentation method was utilized to assess the fracture toughness of the samples. The results revealed that there is a strong correlation between the mechanical properties (hardness, young's modulus, fracture toughness) and the friction coefficient of DLC coatings and the source gas chemistry. Lower hydrogen to carbon ratio in source gas leads to higher hardness, young's modulus, fracture toughness and lower friction coefficient. Furthermore, lower wear volume of the coated materials was observed when the friction coefficient was lower. It was also confirmed that lower hydrogen content of the DLC coating leads to higher wear resistance under nanoscratch conditions.


2020 ◽  
Author(s):  
Funsho Olaitan Kolawole ◽  
Shola Kolade Kolawole ◽  
Luis Bernardo Varela ◽  
Adebayo Felix Owa ◽  
Marco Antonio Ramirez ◽  
...  

Diamond-like carbon (DLC) coatings are amorphous carbon material which exhibits typical properties of diamond such as hardness and low coefficient of friction, characterized based on the sp3 bonded carbon and structure. The proportion of sp2 (graphetically) and sp3 (diamond-like) determines the properties of the DLC. This coating can be applied to automobile engine component in an attempt to provide energy efficiency by reducing friction and wear. However, DLC coatings are faced with issues of thermal instability caused by increasing temperature in the combustion engine of a vehicle. Therefore, it became necessary to seek ways of improving this coating to meetup with all tribological requirements that will be able to resist transformational change of the coating as the temperature increases. This chapter discusses the need for diamond-like carbon coatings for automobile engine applications, due to their ultra-low friction coefficient (<0.1) and excellent wear resistance (wear rate ~ 7 x 10−17 m3/N.m). The importance of DLC coatings deposited using PECVD technique, their mechanical and tribological properties at conditions similar to automobile engines would also be discussed. Non-metallic (hydrogen, boron, nitrogen, phosphorus, fluorine and sulfur) or metals (copper, nickel, tungsten, titanium, molybdenum, silicon, chromium and niobium) has been used to improve the thermal stability of DLC coatings. Recently, incorporation of Ag nanoparticles, TiO2 nanoparticles, WO3 nanoparticles and MoO3 nanoparticles into DLC has been used. The novel fabrication of diamond-like carbon coatings incorporated nanoparticles (WO3/MoO3) using PECVD for automobile applications has shown an improvement in the adhesion properties of the DLC coatings. DLC coatings had a critical load of 25 N, while after incorporating with WO3/MoO3 nanoparticles had critical load at 32 N and 39 N respectively.


2018 ◽  
Vol 883 ◽  
pp. 43-47 ◽  
Author(s):  
Sun Hui Yao ◽  
Yan Liang Su ◽  
Yu Chen Lai ◽  
Huang Ming Wu

This paper reports comparative studies on effects of interlayer on mechanical properties of diamond-like carbon (DLC) coatings. Two interlayers, TiC/Ti and CrC/Cr, were deposited and studied. The DLC coatings were prepared by using an unbalanced magnetron sputtering system. The chemical composition, micro-structure, constituted phases, and fundamental mechanical and tribological properties were evaluated. The results showed that the two amorphous (a-) DLC coatings were obtained. The a-DLC coating with the TiC/Ti interlayer showed higher adhesion, hardness and wear resistance than the one with the CrC/Cr interlayer.


Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 370 ◽  
Author(s):  
Imane Bouabibsa ◽  
Salim Lamri ◽  
Frederic Sanchette

Metal containing hydrogenated diamond-like carbon coatings (Me-DLC, Me = Al, Ti, or Nb) of 3 ± 0.2 μm thickness were deposited by a magnetron sputtering-RFPECVD hybrid process in an Ar/H2/C2H2 mixture. The composition and structure were investigated by Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The residual stress was measured using the curvature method and nanoindentation was used to determine the hardness and the Young’s modulus. A Ball-on-disk tribometer was employed to investigate the frictional properties and sliding wear resistance of films. The results show that the properties depend on the nature and the Me content in the coatings. The doping of the DLC coatings leads to a decrease in hardness, Young’s modulus, and residual stresses. Wear rate of the films first decreases with intermediate Me contents and then increases for higher Me contents. Significant improvements in the friction coefficient on steel as well as in the wear rate are observed for all Al-DLC coatings, and, concerning the friction coefficient, the lowest value is measured at 0.04 as compared to 0.07 for the undoped DLC.


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