Effect of Relative Humidity on the Tribological Properties of Self-Lubricating H3BO3Films Formed on the Surface of Steel Suitable for Biomedical Applications

The effect of environmental humidity on the self-lubricating properties of a thin film of boric acid (H3BO3) was evaluated. H3BO4films were successfully formed on the surface of AISI 316L steel. The study was conducted on AISI 316L steel because of its use in biomedical applications. First, the samples were exposed to boriding to generate a continuous surface layer of iron borides. The samples were then exposed to a short annealing process (SAP) at 1023 K for 5 min and cooled to room temperature while controlling the relative humidity (RH). Five different RH conditions were tested. The purpose of SAP was to promote the formation of a surface film of boric acid from the boron atoms present in the iron boride layers. The presence of the boric acid at the surface of the borided layer was confirmed by Raman spectroscopy and X-ray diffraction (XRD). The self-lubricating capability of the films was demonstrated using the pin-on-disk technique. The influence of RH was reflected by the friction coefficient (FC), as the samples cooled with 20% of RH exhibited FC values of 0.16, whereas the samples cooled at 60% RH showed FC values of 0.02.

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Tribological Behavior of a Self-Lubricant Surface Film of H3BO3 Formed on a Borided Biomedical Steel by a Post-Treatment

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.400.65 ◽

2020 ◽

Vol 400 ◽

pp. 65-74

Author(s):

Enrique Hernández Sánchez ◽

I.P. Torres Avila ◽

A. Chino-Ulloa ◽

C.O. Alvarez ◽

M.A.L. Hernández-Rodríguez ◽

...

Keyword(s):

Thin Film ◽

Solid Lubricant ◽

Tribological Behavior ◽

Surface Film ◽

Post Treatment ◽

Secondary Process ◽

Aisi 316L ◽

316L Steel ◽

The Coefficient Of Friction ◽

Short Annealing

This paper evaluates the tribological behavior of borided AISI 316L steel after being exposed to a secondary process to form a thin film of a solid lubricant. The process known as Short Annealing Process (SAP), allows creating a thin film of boric acid (H3BO3) on the surface of metallic materials previously exposed to boriding. The H3BO3 film acts like solid lubricant due to its lamellar crystalline structure. First samples of AISI 316L were exposed to boriding to temperatures of 875, 925 and 975 °C during 2, 4 and 6 h each temperature. Then, samples were heated to 750 °C during 5 min and cooled to room temperature at 60 % of Relative Humidity. The tribological behavior of the treated samples was evaluated by pin-on-disk test equipped with friction coefficient measurement system. Samples were characterized by Scanning Electron Microscopy, X-Ray Diffraction and Vickers microhardness test. The results showed an evident influence of the experimental parameters on the thickness of the boride layers and their mechanical properties. The layer ́s thickness was ranged from 10.51±0.71 to 51.57±5.12 μm. The hardness of the coatings was increased from 264 to 1685 HV. Finally, the Coefficient of Friction was diminished from values of 0.7 for the as-received material to 0.29 for the borided samples and to 0.06 for those after SAP, which indicates that the post-treatment SAP enhances the tribological properties of the biomedical steel.

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Зависимость механических и трибологических свойств a-C : H : SiO-=SUB=-x-=/SUB=--пленок от амплитуды напряжения смещения подложки

Журнал технической физики ◽

10.21883/jtf.2021.08.51106.15-21 ◽

2021 ◽

Vol 91 (8) ◽

pp. 1286

Author(s):

А.С. Гренадеров ◽

А.А. Соловьёв ◽

К.В. Оскомов ◽

М.О. Жульков

Keyword(s):

Bias Voltage ◽

Steel Surface ◽

Chemical Vapor ◽

Stainless Steel Surface ◽

Aisi 316L ◽

Substrate Bias Voltage ◽

Mechanical And Tribological Properties ◽

316L Steel ◽

The Coefficient Of Friction ◽

Pin On Disk

The paper presents the AISI 316L stainless steel surface modification by plasma-assisted chemical vapor deposition of a-C:H:SiOx film using the pulsed bipolar substrate bias voltage. The mechanical and tribological properties of the a-C:H:SiOx film and the steel surface are examined using the nanoindentation method and the pin-on-disk tribometer, respectively. The optimum value is obtained for the amplitude of the negative pulse of the bipolar bias voltage, when the hardness of the a-C:H:SiOx film is high (19±2 GPa). This hardness value is 3.5 times greater, than the hardness of the AISI 316L steel surface (5.5±0.1 GPa). At the same time, the coefficient of friction of the film is low (0.08), which is 9 times lower than that of the steel (0.72). The wear rate values are found to be 8.5×10-7 and 3.7×10-5 mm3N-1m-1 for the coated and uncoated steel, respectively. The structure and composition of the obtained films are studied by Raman spectroscopy and scanning electron microscopy.

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Reciprocating Wear Behaviour of Non-Coated and Polymer/Composite Coated AISI 316L Steel: Role of Surface Mechanical Attrition Treatment

Tribology Transactions ◽

10.1080/10402004.2021.1950884 ◽

2021 ◽

pp. 1-18

Author(s):

Manoj D. Joshi ◽

Ranjit A. Patil ◽

Yuan-Ron Ma ◽

Rupesh S. Devan ◽

Santosh S. Hosmani

Keyword(s):

Polymer Composite ◽

Surface Mechanical Attrition Treatment ◽

Wear Behaviour ◽

Aisi 316L ◽

Mechanical Attrition ◽

Reciprocating Wear ◽

316L Steel

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Microstructural Fractal Dimension of AISI 316L Steel

MRS Proceedings ◽

10.1557/proc-367-125 ◽

1994 ◽

Vol 367 ◽

Author(s):

M. Hinojosa ◽

R. Rodréguez ◽

U. Ortiz

Keyword(s):

Fractal Dimension ◽

Grain Boundary ◽

Grain Boundaries ◽

Tensile Strain ◽

Optical Microscope ◽

Standard Test ◽

Test Method ◽

Aisi 316L ◽

316L Steel ◽

Deformation Processes

AbstractFractal dimension of the microstructure of AISI 316L steel (17 Cr, 12.7 Ni, 2.1 Mo, 1. 5 Mn, 0.01 C) with different degrees of strain were obtained from Richardson plots of grain boundary perimeter against magnification. Grain boundaries were revealed using conventional metallographic techniques and measurements were taken with the aid of an automatic image analizer (Quantimet 520) attached to an optical microscope. The magnifications used were 50, 100, 200, 400, and 1000X. The samples were obtained from a 4” diameter tubing, machined according to ASTM A370 standard test method and deformed to 5, 10, 15, and 20 % tensile strain. The results show that the fractal dimension of the grain boundaries changes as deformation is imparted to the material.These results suggest that fractal dimension may be used to describe microstructural evolution of metals during deformation processes.

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On the Use of Monolayers to Reduce Evaporation From Stationary Water Pools

Journal of Heat Transfer ◽

10.1115/1.2910650 ◽

1993 ◽

Vol 115 (1) ◽

pp. 209-214 ◽

Cited By ~ 9

Author(s):

T. D. Tang ◽

M. T. Pauken ◽

S. M. Jeter ◽

S. I. Abdel-Khalik

Keyword(s):

Experimental Investigation ◽

Relative Humidity ◽

Water Surface ◽

Surface Film ◽

Free Water ◽

Vapor Concentration ◽

Controlled Environment ◽

Stearyl Alcohol ◽

Water Pool ◽

Evaporation Suppression

An experimental investigation has been conducted to quantify the extent by which monolayers of fatty alcohols can reduce evaporation from a deep stationary water pool within a controlled environment. Octadecanol (stearyl alcohol), C17H35–CH2–OH, was chosen as the surface film and ethanol was selected to be the spreading agent. Evaporation suppression of 60 percent was achieved at a water temperature of 25°C with an air temperature of 20°C and a relative humidity of 70 percent. The experimental techniques and data have been validated by comparing the measured evaporation rates for film-free water with earlier data published by other investigators. Data for the evaporation rates of water covered by octadecanol films were correlated as a function of vapor concentration differences between the water surface and air.

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