A STRATEGY TO ENHANCE THE BIOMEDICAL ARTICULATION SYSTEM BY ELECTROCHEMICALLY TEXTURING OF METAL SURFACES

2012 ◽  
Vol 24 (04) ◽  
pp. 343-347
Author(s):  
Ta-I Yang ◽  
Yi-Chun Chen ◽  
Huei-Ting Huang ◽  
I-Hsiang Tseng ◽  
Hsu-Wei Fang
Keyword(s):  
Friction Coefficient ◽  
Steel Surface ◽  
Electrochemical Etching ◽  
High Load ◽  
Stainless Steel Surface ◽  
Artificial Joint ◽  
Surface Wear ◽  
Textured Surfaces ◽  
Lower Load ◽  
Steel Surfaces

The concept of texturing steel surfaces were attempted to ease the surface wear and to prevent the release of harmful ions in the conventional joint replacement systems. The surfaces of the bio-compatible steels were textured by photolithography and electrochemical etching techniques to lower the friction coefficient and hence reduce the wear of the surface. Experimental results confirmed that the surfaces with textures (grooves) showed lower friction coefficient compared to un-textured surfaces at a high load (50 N). The friction coefficient could be further reduced for a lower load (10 N) through optimizing the generated hydrodynamic lift. A significant 47% reduction of friction coefficient was archived by tailoring the orientation and size of the textures on the stainless steel surface. The demonstrated strategy in this study would thus offer exciting avenues for developing artificial joint systems that last the full duration of the patients' life without any side-effect concerns.

A Research on Friction Properties of Concave Laser-Textured Surface

2012 ◽  
Vol 184-185 ◽  
pp. 33-36
Author(s):  
Hua Qi Liang ◽  
Hui Fang Kong ◽  
Gen Fu Yuan
Keyword(s):  
Friction Coefficient ◽  
Nd:Yag Laser ◽  
Steel Surface ◽  
Surface Friction ◽  
Concave Surface ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Friction Property ◽  
Fine Surface ◽  
Test Result

An object’s fine surface can change the object's surface friction property. So this paper aims to study the friction property of concave laser-textured surface through experiment. First, the Nd:YAG laser is used to generate micro-pores on Cr12 steel surface in the research and then its impact on object's surface friction property is studied. The test result shows that compared with the non-textured surfaces, the concave surface with area density of 5% and depth of I10.8 can reduce the friction coefficient significantly.

Scanning Electron Microscopic Examination of Yersinia enterocolitica Attached to Stainless Steel at Selected Temperatures and pH values1

1988 ◽  
Vol 51 (6) ◽  
pp. 445-448 ◽  
Author(s):  
PAULA J. HERALD ◽  
EDMUND A. ZOTTOLA
Keyword(s):  
Stainless Steel ◽  
Yersinia Enterocolitica ◽  
Steel Surface ◽  
Electron Microscopic Examination ◽  
Growth Conditions ◽  
Stainless Steel Surface ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Steel Surfaces ◽  
Scanning Electron

Attachment of Yersinia enterocolitica to stainless steel surfaces at 35, 21, and 10°C was investigated using scanning electron microscopy (SEM). Cells adhered at all three temperatures, but, in general, the greatest number of adhered cells were observed at pH 8 and 21°C. Multi-flagellated cells were noted under these growth conditions. When grown at pH 9.5 and 21°C, fibrils were observed between cells and extending to the stainless steel surface. Fewer cells with flagella were seen at this pH. Adherence may be related to the flagella and any exopolymer surrounding the cells.

scholarly journals TLC Determination of Mebendazol and Pentoxifylline as Residues on Pharmaceutical Equipment Surfaces

2001 ◽  
Vol 84 (4) ◽  
pp. 1258-1264 ◽  
Author(s):  
Irena Vovk ◽  
Breda Simonovska
Keyword(s):  
Stainless Steel ◽  
Steel Surface ◽  
Stainless Steel Surface ◽  
Linear Calibration ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Steel Surfaces ◽  
Narrow Concentration Range ◽  
Calculated Amount

Abstract This paper presents the applicability of thin-layer chromatographic methods with a subsequent densitometric or video densitometric quantitation for determination of residues in controlling pharmaceutical equipment cleanliness. Analytical methods were developed for monitoring residues of pentoxifylline at 10 mg/m2 and mebendazol at 1 mg/m2 on stainless steel surfaces. Simulated samples were prepared by addition of a calculated amount of pharmaceutical (as a solution) on a 35 × 35 cm stainless steel surface. After evaporation of solvent, the residues were wiped with wetted cotton. The cotton was extracted with dichloromethan–methanol (1 + 1). Filtered extract was concentrated by vacuum evaporation and an aliquot applied to the plate, where standards were also applied. In the narrow concentration range near the acceptable residue limits, linear calibration curve could be obtained for both substances. The mean recovery (n = 4) obtained by densitometric quantitation was 93.4% for pentoxifylline and 85.6% for mebendazol, with coefficients of variation of 3.5 and 8.3%, respectively. Results of video densitometric quantitation did not differ significantly. However, data acquisition and evaluation is faster compared with densitometry and allows better archiving possibilities as required by the regulatory authorities. Both quantitation modes can be applied to routine control of pharmaceutical equipment cleanliness.

Anti-Corrosion Performance of Conductive Copolymers of Polyaniline/Polythiophene on a Stainless Steel Surface in Acidic Media

2020 ◽  
Vol 19 (03) ◽  
pp. 1950023
Author(s):  
Shouqing Xue ◽  
Yuanzhong Ma ◽  
Yunxia Miao ◽  
Weinan Li
Keyword(s):  
Stainless Steel ◽  
Corrosion Behavior ◽  
Steel Surface ◽  
Electrochemical Impedance ◽  
Oxalic Acid Solution ◽  
Stainless Steel Surface ◽  
Corrosion Performance ◽  
Acidic Media ◽  
Steel Composite ◽  
Steel Surfaces

The composite conductive copolymers of polyaniline/polythiophene (Pani/PTH) were successfully prepared by an electrochemical method on a stainless steel surface containing both aniline and thiophene in a 0.3[Formula: see text]mol/L oxalic acid solution. The anti-corrosion performance of the Pani/PTH on stainless steel surfaces was investigated in acidic media by polarization curve analysis and electrochemical impedance spectroscopy (EIS). Additionally, the surface morphology of Pani/PTH composite conductive copolymers was observed by scanning electron microscopy (SEM). The results showed that the Pani/PTH copolymers strongly adhered to the surface of the stainless steel. Compared with that of bare stainless steel, composite conductive copolymers of Pani/PTH on the stainless steel surface provided good anti-corrosion behavior; additionally, the corrosion potential could be improved by approximately 400[Formula: see text]mV, while the current density decreased by two orders of magnitude in the corrosion media. The above results were in accordance with the SEM characterization results. The SEM spectrum showed that the Pani/PTH film had a uniform, dense and shiny structure, so it had better anti-corrosion behavior.

A Global Tribological Approach of Friction Dry Contact Polymer with SGF on Steel, in Terms of Consequences on Metallic Surface Condition (Comparative Wear Coefficients of Steel Surface)

2015 ◽  
Vol 723 ◽  
pp. 927-942 ◽  
Author(s):  
Virgil Florescu ◽  
Lucian Capitanu ◽  
Dorin Rus
Keyword(s):  
Friction Coefficient ◽  
Steel Surface ◽  
Plastic Material ◽  
Normal Load ◽  
Contact Temperature ◽  
Metallic Surface ◽  
Linear Wear ◽  
Sliding Speed ◽  
Dry Contact ◽  
Steel Surfaces

In this paper, we present a global tribological approach of friction dry contact polymer with SGF on steel, in terms of consequences on metallic surface condition (comparative wear coefficients of polished steel surface) based on extensive experimental determinations between the value and the evolution of the friction coefficient, wear of steel surfaces and contact temperature, in the case of linear dry contact, for thermoplastic material reinforced with short glass fibers (SGF) and various steel surfaces. The aim was to highlight the evolution of the wear process depending on the friction coefficient, as well as the dependence of the loading wear and the sliding speed. Wear depth and volume were calculated based on the “wear imprint” method. As a result, it was possible to graphically illustrate the evolution of the friction coefficient, of the contact temperature, and the change of the wear process, emphasizing the abrasive, adhesive and corrosive wear. The evolution of the plastic material transfer function of the contact temperature, namely of the power lost by friction was highlighted. It has been demonstrated that in the case of a 30% SGF content it can reach and even exceed contact temperatures very close to the yield limit of the plastic material. The influence of the normal load and sliding speed was evaluated in detail. The influence of SGF content, normal load, relative sliding speed and contact temperature over the metal surface wear and over the nature of wear mechanism was recorded. The reaction to wear of different steel surfaces in linear dry friction contact on polymers with SGF (polyamide + 20% SGF, polyamide + 30% SGF and polycarbonate with 20% SGF), observing the friction influence over the metallic surfaces wear. The paper includes also its analysis over the steel’s wear from different points of view: the reinforcement content influence and tribological parameters (load, contact pressure, sliding speed, contact temperature, etc.). Thus, authors' findings related to the fact that the abrasive component of the friction force is more significant than the adhesive component are presented, which generally is specific to the polymers’ friction. Authors’ detections also state that, in the case of the polyamide with 30% glass fibres, the steel surface linear wear rate order are of 10-4mm/h, respectively the order of volumetric wear rate is of 10-6cm3/h. The resulting comparative volumetric wear coefficients are of the order (10-11to 10-12) cm3/cm and respectively linear wear coefficients of 10-9mm/cm.

Tribological and Lubrication Properties of Sandblast-Textured Surfaces with Varied Roughness

2010 ◽  
Vol 154-155 ◽  
pp. 1019-1022 ◽  
Author(s):  
Yan Qing Wang ◽  
Hai Feng Yang ◽  
Qing Gong Han ◽  
Liang Fang ◽  
Shi Rong Ge
Keyword(s):  
Friction Coefficient ◽  
Friction And Wear ◽  
Steel Surface ◽  
Hydrodynamic Lubrication ◽  
Testing Machine ◽  
Engine Oil ◽  
Surface Roughening ◽  
Textured Surfaces ◽  
Aisi1045 Steel ◽  
Lubrication Conditions

Surface roughening, with certain roughness topography, is thought to be as an effective tribological method of decreasing friction coefficient of kinematic pairs. Friction and wear of AISI1045 steel surface roughened by convenient and economical way of sandblasting was investigated under lubrication conditions. Roughened and polished samples run against Φ4mm GCr15 pin lubricated by engine oil were tested in reciprocating mode with different load and speed on UMT- testing machine. It is found that there exists the optima surface roughness (Ra is about 3.92μm) roughened by sandblasting in which the least wettability contact angle between engine oil and textured steel surface is obtained, hence the lowest friction coefficient and wear rate is due to the optima hydrodynamic sliding property, although the sliding surface was not in hydrodynamic lubrication state.

Controlling the Leidenfrost Temperature Through Laser-Assisted Surface Micro/Nano Texturing

2013 ◽  
Author(s):  
Corey Kruse ◽  
Troy Anderson ◽  
Dennis Alexander ◽  
George Gogos ◽  
Sidy Ndao
Keyword(s):  
Stainless Steel ◽  
Smooth Surface ◽  
Steel Surface ◽  
304 Stainless Steel ◽  
Stainless Steel Surface ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Transfer Coefficients ◽  
Surface Features ◽  
Leidenfrost Temperature

In the present work, the effect of surface features and wettability on the Leidenfrost temperature are experimentally investigated. The surface features were fabricated on a 304 stainless steel surface using a femtosecond laser. This technique allows for a wide variety of surface microstructures (spikes, mounds, holes, and pyramids) to be created, ranging in size, shape, and spacing. Changing the fluence and shots of the laser produce different micro/nano textured surfaces. A smooth surface sample was fabricated as a reference surface with a measured Leidenfrost temperature as a benchmark. The droplet lifetime experimental method was employed to determine the Leidenfrost temperature for both the smooth and the textured surfaces. A precision dropper was used to control the droplet size to 4.2 microliters (diameter of 2.0mm) while surface temperatures were measured by means of an embedded thermocouple. In comparison to the smooth stainless steel surface, a shift in the Leidenfrost temperature, as high as 55 °C, was observed with the textured surface. The textured surface hasa high emissivity, compared to the smooth surface. As a result, in addition to the shift in the Leidenfrost temperature, significant enhancement of the film boiling heat transfer coefficients were also observed.

Sign in / Sign up

Export Citation Format

Share Document