The Methods of Surface Preparations of Titanium Alloys Applicable for Friction Pairs in Endoprostheses

2016 ◽  
Vol 687 ◽  
pp. 111-116
Author(s):  
Marcin Nabrdalik ◽  
Michał Sobociński

The paper presents the results of tribological tests on titanium alloys subjected to modification of surface layer. The tests were conducted with metal biomaterials coated with TiN layer and anodized, applied in knee and hip joint endoprostheses. One of the ways of improving abrasion resistance of metal and polyethylene elements of endoprostheses is TiN coating by means of PVD method. It results in getting the metal of high bio-compatibility and more friction resistant. The research were carried out for various friction pairs applied in total knee and hip joint endoprostheses.

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 823
Author(s):  
Danko Ćorić ◽  
Mateja Šnajdar Musa ◽  
Matija Sakoman ◽  
Željko Alar

The development of cemented carbides nowadays is aimed at the application and sintering of ultrafine and nano-sized powders for the production of a variety of components where excellent mechanical properties and high wear resistance are required for use in high temperature and corrosive environment conditions. The most efficient way of increasing the tribological properties along with achieving high corrosion resistance is coating. Using surface processes (modification and/or coating), it is possible to form a surface layer/base material system with properties that can meet modern expectations with acceptable production costs. Three coating systems were developed on WC cemented carbides substrate with the addition of 10 wt.% Co using the plasma-assisted chemical vapor deposition (PACVD) method: single-layer TiN coating, harder multilayer gradient TiCN coating composed of TiN and TiCN layers, and the hardest multilayer TiBN coating composed of TiN and TiB2. Physical and mechanical properties of coated and uncoated samples were investigated by means of quantitative depth profile (QDP) analysis, nanoindentation, surface layer characterization (XRD analysis), and coating adhesion evaluation using the scratch test. The results confirm the possibility of obtaining nanostructured cemented carbides of homogeneous structure without structural defects such as eta phase or unbound carbon providing increase in hardness and fracture toughness. The lowest adhesion was detected for the single-layer TiN coating, while coatings with a complex architecture (TiCN, TiBN) showed improved adhesion.


2021 ◽  
pp. 301-308
Author(s):  
V.V. Altukhova ◽  
R.F. Krupsky ◽  
A.A. Krivenok ◽  
O.G. Shakirova

It is shown that vibroabrasive treatment of hardened titanium alloy specimens contributes to an increase in their durability. This effect is explained by the removal of a defective surface layer containing microcracks and subject to the influence of residual tensile stresses. It is shown that the proposed stage of vibro-abrasive processing with ceramic granules makes it possible to almost completely remove iron introduced after vibro-impact surface hardening, which makes it possible to exclude the operation of etching in nitric acid from the technological process. The current state of research on durability in world science is briefly presented.


Tribologia ◽  
2016 ◽  
Vol 268 (4) ◽  
pp. 69-78
Author(s):  
Michał DWORAK ◽  
Adrian BARYLSKI ◽  
Krzysztof ANIOŁEK ◽  
Elizaveta STEPANOVA

The present paper refers to the evaluation of the influence of soaking temperature of nitrided hot work tool steel, X37CrMoV5-1 (WCL), intended for dies for extruding aluminium profiles, on the structure, microhardness, and tribological wear of the nitrided layer. The research involved nitrided steel specimens (X37CrMoV5-1) soaked for 8 hours in an industrial furnace at temperatures of 450°C, 480°C, 520°C, 560°C, and 600°C. For comparison purposes, a REFERENCES material was used, which was not soaked after nitriding. Initially, as the soaking temperature raised, the microhardness of the nitrided layer increased by ca. 10%; however, a further increase in the soaking temperature to more than 450°C caused a decrease in the microhardness of the nitrided layer. The results of tribological tests showed that soaking nitrided steel at a low temperature (450°C) and high temperature (600°C) caused a decrease in tribological wear. Out of the tested materials, the highest microhardness of the upper layer was observed in the samples soaked at 450°C, while the highest resistance to tribological wear was obtained for the samples soaked at 600°C. The conducted tests indicate the possibility of extending the lifetime of dies made from the investigated nitrided steel.


2018 ◽  
Vol 224 ◽  
pp. 01061
Author(s):  
Vitalii Krutsilo ◽  
Nina Papsheva ◽  
Olga Akushskaya

The paper presents data on the research of influence of various methods of hardening on physico- mechanical characteristics of surface layer and performance indicators of details from heatproof, difficult-to-cut steels and titanium alloys working in extreme conditions.


Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 442 ◽  
Author(s):  
Georg Hauer ◽  
Lukas Leitner ◽  
Marc C. Ackerl ◽  
Sebastian Klim ◽  
Ines Vielgut ◽  
...  

Background: The impact of titanium nitride (TiN) coating on implant components is controversial. TiN coating is proposed as having superior biomechanical properties compared to conventional cobalt-chromium (CoCr) alloy. This study compared long-term clinical data as well as meteoro-sensitivity in patients who underwent total knee arthroplasty (TKA), with either CoCr alloy or TiN coating. Methods: In this retrospective observational study, the clinically approved cemented “low contact stress” (LCS) TKA with conventional CoCr coating, was compared to un-cemented TiN-coated “advanced coated system” (ACS) TKA. Propensity score matching identified comparable patients based on their characteristics in a one-to-one ratio using the nearest-neighbor method. The final cohort comprised 260 knees in each cohort, with a mean follow-up of 10.1 ± 1.0 years for ACS patients and 14.9 ± 3.0 years for the LCS group. Physical examinations, meteoro-sensitivity, and knee scoring were assessed. Results: The clinical and functional Knee Society Score (KSS) (82.6 vs. 70.8; p < 0.001 and 61.9 vs. 71.1; p = 0.011), the postoperative Visual Analogue Scale (VAS) (2.9 vs. 1.4; p = 0.002), and the postoperative Tegner Score (2.6 vs. 2.2; p = 0.001) showed significant intergroup differences. The postoperative Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) was similar (79.9 vs. 81.3; p = 0.453) between groups. Meteoro-sensitivity of the artificial joint was significantly more prevalent in the ACS patient cohort (56% vs. 23%; p < 0.001). Conclusion: This study suggests that TiN coating does not provide improved clinical outcomes in this patient cohort after a long-term follow-up. Interestingly, sensitivity to weather changes were more correlated with un-cemented ACS implants.


Vacuum ◽  
2018 ◽  
Vol 149 ◽  
pp. 150-155 ◽  
Author(s):  
M.V. Fedorischeva ◽  
M.P. Kalashnikov ◽  
A.V. Nikonenko ◽  
I.A. Bozhko ◽  
V.P. Sergeev

2018 ◽  
Vol 182 ◽  
pp. 02019
Author(s):  
Maciej Matuszewski ◽  
Małgorzata Słomion ◽  
Janusz Musiał ◽  
Andres Bustilo

In this paper the possibility of using frequency functions of the kinematic pair surface layer elements was analyzed for evaluation of the surface layer condition. The function of spectral power density and autocorrelation which were accepted for analysis was characterized. Evaluation of the elements condition was made on the quantify way as changes in degree of isotropy and in the qualitative way based on the graphs of the analyzed frequency functions. After tribological tests the surface structures were adopted to assess the changes. Spectral graphs for structures without cooperation (directly after-machining) and for the different friction distance, were analyzed. Conditions during tribological tests were taken as permanent. The determined degree of isotropy basis on the frequency functions and received graphs of spectra power density function and autocorrelation become useful in evaluation of the surface layer changes during its transformation.


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