Mapping the friction coefficient of AISI 316L on UHMWPE lubricated with bovine serum to study the effect of loading and entrainment at high values of sliding-to-rolling ratio (original) (raw)
Related papers
Wear, 2006
In this work, the most commonly used joint materials for substitution of hip joints, ultra high molecular weight polyethylene (UHMWPE) for the cup, and alumina, stainless steel or CoCrMo alloy for the head, were submitted to pin-on-disk tribological tests. The interfacial behaviour prosthetic material/lubricant was investigated through wettability measurements. Four lubricants were used: Hanks’ balanced salt solution (HBSS) and solutions of bovine serum albumin (BSA), of hyaluronic acid (HA) and of both components (BSA + HA) in HBSS. It was observed that the friction coefficient increased significantly with time, in a random way, when the lubricant did not contain albumin. The addition of HA induced a slight reduction in the initial value of the friction coefficient but did not affect qualitatively its behaviour for longer times. Observation of the worn metallic surfaces revealed parallel grooves typical of abrasive wear and also lumpy transfer film of UHMWPE, while the transfer of polymer to alumina was incipient. Wear was particularly intense on the steel surface where delamination and fatigue wear mechanisms were also found. In the presence of albumin, the friction coefficient remained constant and small for the metallic surfaces and increased in the case of alumina. The observation of the worn surfaces showed that the presence of albumin in the lubricant avoided the transfer of polymer for the metallic surfaces but not for the alumina surfaces. These results, together with the wettability measurements, strongly indicate that the presence of albumin in the lubricant avoids the adhesion and transfer of UHMWPE only for the least hydrophilic surfaces, which are the metallic ones.
Estimation of appropriate lubricating film thickness in ceramic-on-ceramic hip prostheses
AIP Conference Proceedings, 2016
Artificial hip prostheses, consisting of femoral head and acetabular cup are widely used and have affected the lives of many people.However, the primary issue associated with the long term performance of hip prostheses is loosening induced by excessive wear during daily activity. Therefore, an effective lubrication is necessary to significantly decrease the wear. To help understand the lubricating performance of such typical hip joint prostheses, in the present paper a hydrodynamic lubrication model based on Reynolds equationwas introduced. The material pairs of ceramic acetabular cup against ceramic femoral head was investegated.The main aim of this study is to investigate of the effect of loading on the formation of lubricating film thickness.The model of a ball-in-socket configuration was considered assuming that the cup was stationary while the ball was to rotate at a steady angular velocityvarying loads.Based on simulation result, it was found that to promote fluid film lubrication and prevent the contacting components leading to wear, the film thickness of lubricant should be determined carefully based on the load applied. This finding may have useful implication in predicting the failure of lubricating synovial fluid film and wear generation in hip prostheses.
Recent Advances in Bio-Tribology From Joint Lubrication to Medical Implants: A Review
Journal of Materials and Engineering, 2024
Bio-tribology, the study of lubrication, wear, and friction in biological systems, has made recent strides in the lubrication of medical implants and joints. This comprehensive review discusses the most recent developments in bio-tribology, with an emphasis on the transition from basic science to medical engineering applications. An overview of bio-tribology and its increasing significance in medicine commences the study. Following this, recent research on the composition of synovial fluid and its function in minimizing friction in natural joints is discussed. Medical implant tribology, including degradation issues in dental prostheses and joint replacements, is then addressed. This study investigates the manner in which surface modifications and coatings improve the tribological performance of medical implants. It emphasizes recent developments in material science and engineering. This article emphasizes the significance of minimizing implant material degradation in relation to the functionality and longevity of biomedical devices. Following this, digital models, simulations, and state-of-the-art imaging techniques that have propelled bio-tribology forward are highlighted. In addition to proposing potential research avenues to overcome the current obstacles, the article highlights the interdisciplinary nature of bio-tribology and urges collaboration among tribology, materials science, and biomechanics researchers.
Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2008
Lubrication modelling is of great importance in the design of artificial hip joints, especially for the demand of long life expectancy of those joints employing a metal-on-metal bearing. Through lubrication analysis, the dimensions of the head/cup and the clearance between them can be reasonably determined, and thus, if fluid film lubrication can be generated in artificial hip joint replacements, the wear and related failure can be reduced. In the majority of published numerical studies of the lubrication of hip joints, the synovial fluid for the natural joint and bovine serum used for in vitro simulator testing of joint replacements have always been treated as isoviscous, incompressible Newtonian fluids because the viscosity of these lubricants is almost unchanged at high shear rate. However, all these biological lubricants generally exhibit non-Newtonian characteristics of shear thinning, particularly under relatively low shear rates, and display a second Newtonian plateau at high shear rates.
Limitation of the Lubricating Ability of Total Hip Prostheses with Hard on Hard Sliding Material
Tribology Online, 2013
Recently, metal on metal hip prostheses have been revived following excellent clinical results. However, the risk of wear diseases has not been removed yet. Fluid film formation is necessary for long term reliability of a total hip prosthesis because solid contact of the prosthesis induces serious wear. However, the fluid film can be only formed under limited conditions together with an appropriate shape design. Radial clearance is also an important factor because the radius has an upper limit in the joint space. A radial clearance that is too small induces severe contact, whereas decreasing radial clearance enhances squeezed film formation. The most appropriate radial clearance currently remains unclear. We prepared some specimens with high accuracy of polishing, which were balls and cups of the Co-Cr-Mo alloy with a common radius of 16 mm and several radial clearances, 0.15-95.8 µm. Their lubricating ability was evaluated by a friction test using a pendulum machine. The frictional coefficient was a local minimum where the radial clearance was 20-30 µm. It was found that appropriate radial clearance of a total hip prosthesis with hard on hard material must exist within this range.
Journal of Thermoplastic Composite Materials
The present work focuses on evaluating the tribological behavior of ultrahigh molecular weight polyethylene (UHMWPE) with 316L stainless steel and Ti6Al4V under dry and lubricated sliding conditions using human body fluids (synovial fluid and human serum). Eighteen trials of experiments were performed using a reciprocating sliding tribometer (pin-on-disc) at 37°C based on Taguchi’s L18 (21 × 32) array. The in-vitro experimental results revealed that UHMWPE offers better tribological performance under synovial fluid lubrication conditions irrespective of the counterface material. The optimization of the response variables (coefficient-of-friction (COF) and specific wear rate (WR)) was performed using optimization techniques (Taguchi and Grey relational analysis). It was revealed that Ti6Al4V counterface material under synovial fluid lubrication and normal load of 52 N exhibits the optimal tribological performance with UHWMPE. The contribution of process parameters on the COF and WR w...
Journal of the mechanical behavior of biomedical materials, 2018
Friction is the natural response of all tribosystems. In a total knee replacement (TKR) prosthetic device, its measurement is hindered by the complex geometry of its integrating parts and that of the testing simulation rig operating under the ISO 14243-3:2014 standard. To develop prediction models of the coefficient of friction (COF) between AISI 316L steel and ultra-high molecular weight polyethylene (UHMWPE) lubricated with fetal bovine serum dilutions, the arthrokinematics and loading conditions prescribed by the ISO 142433: 2014 standard were translated to a simpler geometrical setup, via Hertz contact theory. Tribological testing proceeded by loading a stainless steel AISI 316L ball against the surface of a UHMWPE disk, with the test fluid at 37 °C. The method has been applied to study the behavior of the COF during a whole walking cycle. On the other hand, the role of protein aggregation phenomena as a lubrication mechanism has been extensively studied in hip joint replacement...
The wear of artificial finger joints using different lubricants in a new finger wear simulator
2001
A new design of finger wear simulator has been manufactured. The simulator is a dual cycle machine, interspersing dynamic flexionextension motion, where the loads were 10-15 N, with periods of a static 100 N 'pinch' load. Also, a two-piece finger prosthesis has been designed and manufactured from silane cross-linked polyethylene. Using the simulator, a comparison of the wear of the cross-linked polyethylene prosthesis was undertaken, with Ringer solution, distilled water and dilute bovine serum as the lubricants. Each test was run at 37 • C and included a control prosthesis to account for lubricant uptake. All prostheses came from the same batch, having a gel content of 87%. In total, testing exceeded 27 million cycles. With bovine serum, the total wear factor for the prosthesis was 0.07 × 10 −6 mm 3 /N m. With Ringer solution it was 0.98 × 10 −6 mm 3 /N m and with distilled water the wear factor was 0.60 × 10 −6 mm 3 /N m. This order of results matched that found with pin on plate wear tests using these same three lubricants. The lower wear found with bovine serum may have been due to the positive boundary lubricating effects of the proteins within the serum. Lubricant uptake was greater and more significant in the bovine serum test.
Friction behaviour of hydrophilic lubricious coatings for medical device applications
Tribology International, 2015
The friction behaviour of new chitosan derivative coatings obtained by chemical modification of chitosan with fatty acids (linoleic and dilinoleic acid) has been investigated in order to explore their potential as endovascular catheter coatings and to benchmark them against commercially available coatings used in endovascular catheter applications. An in vitro tribological system was developed that was intended to represent to a limited extent the in vivo tribological conditions of a typical endovascular catheterization procedure. Continuous reciprocating sliding tests were carried out with uncoated and coated polymer specimens. The results showed that all of the coatings tested decreased the coefficient of friction compared to the uncoated polymer. Compared to a neat chitosan coating, the chitosan derivative coatings showed a clear reduction in the coefficient of friction to levels similar to those of the commercially-available coatings. A comparison between the friction results and contact angle measurements carried out on the coatings indicated that a range of contact angle values exists for which the friction coefficient is at a minimum. The reason for this is unclear and further studies are required in order to confirm and investigate the trend, especially within the context of hydrophilic lubricious coating development. .pl (A. Niemczyk), mirfray@zut.edu.pl (M. El Fray), s.e.franklin@philips.com (S.E. Franklin). Please cite this article as: Niemczyk A, et al. Friction behaviour of hydrophilic lubricious coatings for medical device applications. Tribology International (2015), http://dx.
Malaysian Journal of Medicine and Health Sciences, 2020
Introduction: The lubricant thickness in clearance between bearing surfaces for metallic hip implants are currently incapable of accommodating the motion experienced (high load and low entraining motion) in hip walking cycle. Thus, micro-dimpled surfaces were introduced onto surfaces of metallic acetabular cups to improve lubricant thickness. Micro-dimpled surface is a method of advanced surface improvement to increase the lubricant thickness in various tribological applications, such as hip implants. However, the application of micro-dimpled surfaces in hip implants has not yet been explored adequately. Therefore, this study aims to identify the influence of micro-dimpled depth on lubricant thickness elastohydrodynamically for metallic hip implants using Fluid-Structure Interaction (FSI) approach. Methods: Fluid-Structure Interaction (FSI) approach is an alternative method for analysing characteristics of lubrication in hip implant. Dimples of radius 0.25 mm and various depths of 5μm, 45μm and 100μm were applied on the cup surfaces. The vertical load in z-direction and rotation velocity around y-axes representing the average load and flexion-extension (FE) velocity of hip joint in normal walking were applied on Elastohydrodynamic lubrication (EHL) model. Results: The metallic hip implants with micro-dimpled surfaces provided enhanced lubricant thickness, namely by 6%, compared to non-dimpled surfaces. Furthermore, it was suggested that the shallow depth of micro-dimpled surfaces contributed to the enhancement of lubricant thickness. Conclusion: Micro-dimpled surfaces application was effective to improve tribological performances, especially in increasing lubricant thickness for metallic hip implants.