scholarly journals Evaluating the Mechanical and Tribological Properties of DLC Nanocoated Aluminium 5051 Using RF Sputtering

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
L. Natrayan ◽  
Anjibabu Merneedi ◽  
Dhinakaran Veeman ◽  
S. Kaliappan ◽  
P. Satyanarayana Raju ◽  
...  

The diamond-like carbon- (DLC-) coating technique is used in the sliding parts of automotive engines, among other applications, to reduce friction and wear. In this work, DLC has been coated on the Aluminium 5051 sample to assess the mechanical and tribological properties. A sputtering deposition mechanism is used, and the DLC is coated using a graphite target. The developed DLC coatings are tested for adhesion strength, hardness, chemical composition using XRD, and wear behaviour. The developed DLC thin films have considerably increased the wear behaviour of the Aluminium 5051 sample and have fulfilled the objective of this study. The XRD data indicated the presence of amorphous carbon in the coating with a threefold increase to the hardness of the naked aluminium. This study provides insight into improving the aluminium wear resistance by developing a considerably hard coating.

2021 ◽  
Vol 2131 (5) ◽  
pp. 052038
Author(s):  
A V Sidashov ◽  
M V Boiko ◽  
E I Luneva ◽  
A M Popov

Abstract The combination of unique physicochemical, mechanical and tribological properties of diamond-like coatings determines the prospects for their use in critical friction units, including those operating in a rarefied atmosphere and vacuum. The properties of diamond-like carbon (DLC) coatings depend on the contribution of the sp2 and sp3 fractions of the carbon hybrid atomic electron orbitals. Modern methods of determining the graphite and diamond proportion in coatings are time-consuming and insufficiently accurate. In addition, the determination of the sp3/sp2 ratio is often difficult due to the displacement of the energy position of the C1s electron line. In this paper, the change in the chemical state of carbon over the thickness of a diamond-like coating is studied by X-ray photoelectron spectroscopy. Analysis of the carbon line fine structure of the differential graphite spectra (sp2 bonds) and diamond (sp3 bonds) allowed us to establish the parameter δ, which determines the ratio of the graphite and diamond components in the DLC coating. Profiling with Ar+ ions of the diamondlike coating surface showed that with an increase in the etching time, the proportion of amorphized carbon increases, which means that the antifriction properties increase with the abrasion of the coating. The obtained regularities allow us to predict changes in the tribological properties of DLC coatings during operation. Ion profiling also allows to determine the thickness of coatings with high accuracy.


Author(s):  
S Rambabu ◽  
N Ramesh Babu

This article covers the efforts on characterising ice-bonded abrasive polishing tool in terms of the mechanical and tribological properties such as hardness, coefficient of friction, and wear rate. These studies were attempted on the tools prepared at different temperatures ranging from −10 °C to 0 °C with a view to identify the condition suitable to prepare ice-bonded abrasive polishing tool for effective polishing of Ti–6Al–4V alloy specimen. It also presents the methods adopted to determine various properties of ice-bonded abrasive polishing tool. Hardness was estimated from the measured penetration depth of cone shape indenter into the tool, coefficient of friction was determined from the change in power drawn by the motor rotating the tool mould, and wear behaviour of tool was assessed from the melting rate of the tool determined from the change in height of ice-bonded abrasive polishing tool at different stages of polishing. From the results of this study, it is clear that ice-bonded abrasive polishing tool prepared at −4 °C has possessed sufficient hardness, coefficient of friction, and reasonable wear rate suitable for polishing of Ti–6Al–4V specimens. This article also covers the details of low-temperature coolant supply unit developed to prepare the ice-bonded abrasive polishing tool at any desired temperature between 0 °C and −40 °C and thus to maintain it for a long time. Polishing studies with such ice-bonded abrasive polishing tool showed 72% improvement in finish after 90 min of polishing of Ti–6Al–4V specimen with tool, prepared at −4 °C.


2020 ◽  
Vol 37 (1−2) ◽  
Author(s):  
SRIDHAR ATLA ◽  
Prasanna Lakshmi Kaujala

The aluminium metal matrix composite reinforced with ceramic material of Silicon carbide (SiC) has good mechanical properties. However, aluminium based ceramic composites require improvements in their lubrication and tribological properties. In this study an attempt is made in the development of a new material through powder metallurgy technique by the addition of Graphite, which acts as a solid lubricant. This work investigated the influence of graphite on the wear behaviour of Al 7075/SiC /X wt.% graphite(X=0, 5 and 10) hybrid composite. The investigation reveals the effectiveness of incorporation of graphite in the composite for gaining wear reduction. The Al 7075 (aluminium alloy 7075) reinforced with SiC –graphite were investigated. The composites were fabricated using powder metallurgy route. The microstructures, material combination, wear and friction properties were analysed by scanning electron microscopy, XRD, and pin-on-disc wear tester. The newly developed aluminium composite has significant improvements in tribological properties with a combination of 5% Silicon carbide (SiC) and 5% Graphite. The test reveals that sliding distance of 1000 m and sliding speed of 1.5 m/s with applied load of 5 N result in minimum wear loss of 0.01062g and coefficient of friction as 0.1278.


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.


2014 ◽  
Vol 59 (4) ◽  
pp. 1263-1268 ◽  
Author(s):  
I. Sulima

Abstract mechanical and tribological properties of sintered 316L stainless steel composites with TiB2 submicroparticles were investigated. The composites were manufactured by Spark Plasma Sintering (SPS). The wear behaviour was studied by using a ball-on-disc wear tester at room temperature. The worn surface were analysed using Scanning Electron Microscopy (SEM). The results indicated that the friction coefficient and the wear resistance of composites with the same content of TiB2 particles depend on the sintering conditions.


An attempt is made to find the mechanical and tribological properties of Al6061/Gr metal matrix composites (MMC) produced using stir casting method. It is important to note that the certain components require high hardness and wear resistance to fulfil the functional requirements, the said properties of the MMCs influenced largely on the condition with which they are produced or treated. Therefore, in the present paper the composites are tested in two stages that is before T6 heat treatment and after T6 heat treatment respectively. The composites are made with Al6061 alloy as matrix and graphite with 3%, 6%, 9% and 12% by wt is considered as reinforcement. Once the composites are prepared, they are examined for their microstructural, mechanical, and tribological properties. Further, a response surface methodology (RSM) has been used to model the wear loss and coefficient of friction for both before and after T6 heat treatment of MMCs. The non-linear regression model obtained is validated both statistically and with the help of experimental test cases. The evidence of wear phenomenon has been observed with the help of Scanning Electron Microscopy (SEM). Further, fuzzy grey relational Technique has been used to determine the multi performance index for the dry sliding wear and friction phenomenon of the developed composite.


Author(s):  
J. Palmers ◽  
K. Vanhollebeke ◽  
J. P. Celis ◽  
T. Van der Donck

The aim of this study was the investigation of the fretting wear of industrial and newly developed multi-layered coatings. The tribological behaviour of flat DLC coated specimens was investigated in fretting mode I and fretting mode II against different ball counterbodies namely, corundum, 100Cr6, and DLC coated 100Cr6 using a broad range of strokes, frequencies, and loads. From Fretting I a dependency of the wear behaviour with the type of DLC coating, and an influence of the normal load with the coefficient of friction was observed. Using Fretting mode II, an attempt was made to study the fatigue and toughness properties of the coatings.


2006 ◽  
Vol 15-17 ◽  
pp. 1026-1031
Author(s):  
Damiano Galvan ◽  
Y.T. Pei ◽  
Jeff T.M. de Hosson ◽  
Albano Cavaleiro

A commercial RF-sputtering deposition rig was employed to deposit H-free diamond-like carbon (DLC) coatings. The influence of alloying elements such as Ti and Si on the structure, mechanical and tribological properties of the coatings was investigated. The coating was observed in cross section and in plan view with SEM, TEM and AFM. Because of the highly-ionized plasma generated by the RF-powered glow discharge, ion bombardment suppresses the formation of a columnar structure regardless of the composition of the coatings. The method produces featureless microstructures and smooth surfaces. TEM investigations confirm that no crystalline phases form in the coatings regardless of the presence of considerable concentrations of Ti and Si. Tribological tests were performed with a high-temperature tribometer in a ball-on-disk configuration, using coated disks and different materials for the ball countepart. At ambient T the sliding friction coefficient decreases as the concentration of alloying elements increases. Nevertheless, high-T tribotests with a constant thermal load showed that the presence of alloying elements decreases the thermal stability of the coatings. For each coating a temperature exists above which a sudden increase of friction coefficient is observed, with subsequent detachment and failure of the coatings. The mechanism of disruption of the self-lubrication effects is identified and the influence of the alloying elements on the thermal degradation of tribological performance of the coatings is discussed.


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.


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