Improved adhesion of diamondlike coatings using shallow carbon implantation

2000 ◽  
Vol 15 (3) ◽  
pp. 590-592 ◽  
Author(s):  
Gerard W. Malaczynski ◽  
Alaa A. Elmoursi ◽  
Chi H. Leung ◽  
Aboud H. Hamdi ◽  
Albert B. Campbell

A surface layer of metal carbides provides an excellent interface to achieve a highly adherent diamondlike carbon (DLC) coating. A plasma immersion ion implantation (PIII)-based procedure is described, which delivers a high retained dose of implanted carbon at the surface of aluminum alloys. A shallow implantation profile, followed by argon sputter cleaning and continued until a saturated carbon matrix is brought to the surface, provides an excellent interface for subsequent growth of DLC. At a carbon retained dose above 1018 atoms/cm2 the DLC adhesion exceeds the coating's cohesion strength. Regardless of the silicon content in the aluminum, the coating produced by this method required tensile strengths typically exceeding 140 MPa to separate an epoxy-coated stud from the coating in a standard pull test. Improved DLC adhesion was also observed on chromium and titanium. The reported tensile strength is believed to substantially exceed performance of DLC coatings produced by any other method.

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Said Jahanmir ◽  
Hooshang Heshmat ◽  
Crystal Heshmat

Diamondlike carbon (DLC) coatings, particularly in the hydrogenated form, provide extremely low coefficients of friction in concentrated contacts. The objective of this investigation was to evaluate the performance of DLC coatings for potential application in foil bearings. Since in some applications the bearings experience a wide range of temperatures, tribological tests were performed using a single foil thrust bearing in contact with a rotating flat disk up to 500°C. The coatings deposited on the disks consisted of a hydrogenated diamondlike carbon film (H-DLC), a nonhydrogenated DLC, and a thin dense chrome deposited by the Electrolyzing™ process. The top foil pads were coated with a tungsten disulfide based solid lubricant (Korolon™ 900). All three disk coatings provided excellent performance at room temperature. However, the H-DLC coating proved to be unacceptable at 300°C due to lack of hydrodynamic lift, albeit the very low coefficient of friction when the foil pad and the disk were in contact during stop-start cycles. This phenomenon is explained by considering the effect of atmospheric moisture on the tribological behavior of H-DLC and using the quasihydrodynamic theory of powder lubrication.


1999 ◽  
Vol 14 (5) ◽  
pp. 2173-2180 ◽  
Author(s):  
M. Nastasi ◽  
P. Kodali ◽  
K. C. Walter ◽  
J. D. Embury ◽  
R. Raj ◽  
...  

The fracture behavior of diamondlike carbon (DLC) coatings on Si substrates has been examined using microindentation. The presence of DLC coatings reduces the radial crack length to less than one-half the crack length observed in uncoated Si at the same indenter load. A total work of fracture analysis of the radial cracks formed in the DLC-coating/Si-substrate system gives 10.1 MPa m1/2 as the average fracture toughness for DLC alone. A bond-breaking calculation for DLC suggests that the elastic limit fracture toughness should be 1.5 MPa (m)1/2. The higher value obtained from experiment and total work analysis suggests that plastic work and/or a tortuous path crack evolution occurred during DLC fracture process.


2008 ◽  
Vol 23 (7) ◽  
pp. 1862-1869 ◽  
Author(s):  
Ayesha J. Haq ◽  
P.R. Munroe ◽  
M. Hoffman ◽  
P.J. Martin ◽  
A. Bendavid

The deformation behavior of diamondlike carbon (DLC) coatings on silicon substrates induced by Berkovich indentation has been investigated. DLC coatings deposited by a plasma-assisted chemical vapor deposition technique were subjected to nanoindentation with a Berkovich indenter over a range of maximum loads from 100 to 300 mN. Distinct pop-ins were observed for loads greater than 150 mN. However, no pop-out was observed for the loads studied. The top surface of the indents showed annular cracks with associated fragmented material. The cross sections showed up to 20% localized reduction in thickness of the DLC coating beneath the indenter tip. Cracking, {111} slip, stacking faults, and localized phase transformations were observed in the silicon substrate. The discontinuities in the load–displacement curves at low loads are attributed to plastic deformation of the silicon substrate, whereas at higher loads they are attributed to plastic deformation as well as phase transformation.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 376
Author(s):  
Mao Kaneko ◽  
Masanori Hiratsuka ◽  
Ali Alanazi ◽  
Hideki Nakamori ◽  
Kazushige Namiki ◽  
...  

We evaluated the adhesion, friction characteristics, durability against bodily acids, sterilization, cleaning, and anti-reflection performance of diamond-like carbon (DLC) coatings formed as a surface treatment of intracorporeal medical devices. The major coefficients of friction during intubation in a living body in all environments were lower with DLC coatings than with black chrome plating. DLC demonstrated an adhesion of approximately 24 N, which is eight times stronger than that of black chrome plating. DLC-coated samples also showed significant stability without being damaged during acid immersion and high-pressure steam sterilization, as suggested by the results of durability tests. In addition, the coatings remained unpeeled in a usage environment, and there was no change in the anti-reflection performance of the DLC coatings. In summary, DLC coatings are useful for improving intracorporeal device surfaces and extending the lives of medical devices.


2020 ◽  
pp. 558-563
Author(s):  
I.A. Buyanovskii ◽  
M.M. Khruschov ◽  
V.D. Samusenko ◽  
Yu.I. Schsherbakov ◽  
M.V. Atamanov ◽  
...  

The results of an experimental study of the tribological characteristics of inactive, surface-active, and chemically active lubricants in the boundary lubrication mode when steel is rubbed against steel with a carbon diamond-like (Cr—DLC)-coating. For comparison, also tested friction in these friction contacts under similar conditions, but without lubricant. The maximum coefficient of friction and maximum wear was obtained by tribological testing of steel on steel. The minimum coefficient of friction was obtained when steel was rubbed against Сr—DLC-coated steel in a surface-active lubricant medium.


2002 ◽  
Vol 16 (06n07) ◽  
pp. 952-957 ◽  
Author(s):  
D. Sheeja ◽  
B. K. Tay ◽  
H. M. Lam ◽  
S. K. Ng

The Co-Cr-Mo alloy is extensively used for tribological applications, including orthopaedic components in total joint replacements. High quality diamond-like carbon (DLC) coatings on metal/alloy substrates are of great interest as they are able to protect them from severe wear and thus prolong the life span of the component. Since the roughness of the metal/alloy varies depending on the applications, a study has been carried out to investigate the effect of substrate surface roughness on the microstructure, sliding life, wear-resistance, coefficient of friction, adhension and hardness of DLC coatings prepared on Co-Cr-Mo alloy substrates under the same deposition condition. The microstructure of the films studied using Raman spectroscopy suggests that the film prepared on a smoother surface contains slightly higher fraction of sp 3 bonded carbon atoms. The characterization using a pin-on-disk tribometer reveals that, the film prepared on the roughest sample (Ra ~ 0.06 μm) exhibits a very short life span of about 20 cycles compared to the film that is prepared on a relatively smoother surface (Ra ~ 0.02 μm), which exhibits a life span of about 340,000 cycles. In order to investigate the origin of this improved property of the DLC film on the smoother surface, adhesive strength and hardness of the films were studied by using a micro-scratch tester and a Nano-indenter, respectively. The results suggest that the film prepared on the smoother surface exhibits better adhesion (higher critical load) and relatively higher hardness.


2008 ◽  
Vol 17 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Langping Wang ◽  
Lei Huang ◽  
Yuhang Wang ◽  
Zhiwen Xie ◽  
Xiaofeng Wang

Author(s):  
R. J. Narayan

Hydrogen-free diamondlike carbon (DLC), with hardness values close to that of diamond, possess many desirable biocompatible properties for a variety of biomedical applications. The DLC coatings can be applied to joints prostheses, heart valves, and other medical devices. Unfortunately, hydrogen-free DLC coatings have a large compressive stresses which result in poor adhesion and wear characteristics. In this paper, we present results on silver doping of DLC to alleviate internal stresses as well as create DLC-Ag nanocomposites where Ag is in the form of nanoparticles. The Ag nanoparticles are expected to impart antimicrobial properties by providing sources of electrons. In the second part of the paper, we have created DLC and nanotube composites where nanotubes grow normal to the surface. This novel architecture not only alleviates internal stresses, but DLC + Nanotube composites have enhanced hardness and unique antimicrobial properties. Finally, we discuss novel multilayer DLC and hydroxyapatite (HA) composite where HA and DLC films are deposited sequentially at room temperature. The HA films with composites close to that of bone is considered very desirable for biocompatibility and integration with base structures. We discuss novel processing, characterization, hardness and bioeompatible properties of all these composites in detail.


2018 ◽  
Vol 2 (3) ◽  
pp. 41-47
Author(s):  
V. V. Vasylyev ◽  
V. E. Strel’nitskij ◽  
V. B. Makarov ◽  
M. A. Skoryk ◽  
G. O. Lazarenko

Abstract Hard coatings are increasingly being used in medicine to protect metal endoprostheses The experimental process for the high-productive synthesis of high-quality diamond-like carbon (DLC) coatings with high hardness and a sufficiently high level of adhesion to the spherical shaped parts of the hip joint made from the stainless steel or cobalt-chrome alloy have been developed. DLC coating deposition was performed by vacuum-arc method from a high-productive source of the filtered vacuum-arc carbon plasma of rectilinear type with a "magnetic island". The high degree of thickness uniformity in the coating on the head of the hip joint with a high adhesion to the metal joint base was developed. Modernization of the vacuum arc plasma source allowed to accelerate the cathode spot motion, exclude substrate overheating and increase the diamond-like carbon hardness up to 30-40 GPa. The high adhesion level was achieved as a result of the high voltage pulsed of substrate bias potential use and multilayer architecture of DLC coating. The DLC coating on the heads of hip endoprosthesis did not peel off when boiling endoprosthesis or when immersing it into the liquid nitrogen.


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.


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