Wyniki wyszukiwania - Biblioteka Nauki

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Combustion Synthesis of Titanium Carbonitrides

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Dyjak S. , Wasilewska M. , Cudziło S.

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2015

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tom Vol. 12, no. 2

249--259

EN

Titanium carbonitride (TiC0.5N0.5) micron powders were synthesized in reactions of titanium with zinc dicyanide: Zn(CN)2 + 4Ti → 4TiC0.5N0.5 + Zn. The reactions are sufficiently exothermic to propagate in the reactant mixture to form a self-sustaining, high-temperature synthesis (SHS). The final product was separated and the only byproduct (zinc) was removed by dissolution in dilute hydrochloric acid. The use of zinc dicyanide as the source of carbon and nitrogen causes the titanium carbonitride to contain only these elements in an atomic ratio of one. The reaction temperature can be easily reduced by the addition of zinc powder to the green mixture. Synthesis in the presence of zinc yields TiC0.5N0.5 powders consisting of round-shaped and unagglomerated particles.

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The study of the tribological properties under high contact pressure conditions of TiN, TiC and TiCN coatings deposited by the magnetron sputtering method on the AISI 304 stainless steel substrate

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Mamaeva A. A. , Kenzhegulov A. K. , Panochkin A. V. , Alibekov Z. Z. , Kshibekova B. B. , Wieleba W. , Leśniewski T. , Bakhytuly N.

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tom Vol. 41, No. 1

1--14

EN

Titanium carbonitride coatings are widely used to improve the wear resistance of surfaces. The results of tribological investigations of TiC, TiN, and TiCN coatings deposited on an AISI 304 steel substrate by the magnetron sputtering method were presented. The research aimed to describe the wear processes of the coatings during friction in an emergency situation, i.e. with a lack of lubrication and concentration of pressure in a small contact area. Tribological tests were performed on a ball-on-disk tribotester in reciprocating motion under technically dry friction conditions. The Hertz pressure in the contact area was ph = 2500-2700 MPa. Additionally, scratch tests and microscopic observations of the surfaces of the samples were performed after tribological tests to describe the wear process of the coatings. The results showed cracking, and coatings detachment from the substrate occur during friction. Deformation wear was observed as bulges in the material at the edge of the friction path. The deformation occurred primarily in the substrate material despite friction occurring on the surface of the coating. The best coating in terms of tribological properties was the TiN coating, which showed the highest resistance to wear in an emergency situation and the friction coefficient in the final stage of the test (above 90 cycles of movement) was only slightly higher than the values recorded for the other coatings. The TiN coating had high hardness, showed good adhesion to the substrate, and was not cracked, protecting it from damage.

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Structure and properties of TiN and Ti(C,N) coatings on Co high-speed steels.

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Dobrzański L. A. , Adamiak M.

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tom R. XIX, nr 4

986-987

EN

The paper present results of investigations of the type base material of the W-Mo-V-Co+Si, with economically adjusted chemical composition on structure and properties of hard, wear resistant coatings of titanium nitride TiN and titanium carbonitride Ti(C,N), deposited in the PVD process. It was shown that high-speed steels containing 9%-11% tungsten, 2% molybdenum and limited the Co concentration from 10% to about 5%, coated in the PVD process expose properties comparable with the ones obtained on the others high-speed steels grades. This makes it possible to employ in practice the high-speed steels with relatively low concentration of the alloying elements instead of the high-alloy cobalt steels, provided the base heat treatment is carried out so that it ensures the maximum secondary hardness.

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Possibilities of applying Ti (C, N) coatings on prosthetic elements : research with the use of human endothelial cells

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Banaszek K. , Wiktorowska-Owczarek A. , Kowalczyk E. , Klimek L.

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2016

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tom Vol. 18, no. 1

129--136

EN

Purpose: The aim of our study was to examine the effect of prosthetic alloys with Ti (C, N) coatings on viability and pro life ration of human cells employing an MTT assay with the use of human microvascular endothelial cells derived from the skin – HMEC-1 (Human Microvascular Endothelial Cells-1). Methods: Cylindrical shape samples made of Ni-Cralloy were divided into S1-S5 groups and coated with Ti (C, N) layers with different content of C and N. S0 group – control group without layer. The alloys (S0-S5) were stored in an experimental medium (MCDB131 with antibiotics) for 30 days and then HMEC-1 cells were incubated in the alloy extract for 24 and 96 hours. Next, cell viability was determined using MTT method. Results: In the case of samples incubated for both 24 and 96 hours there are statistically significant differences (with p-value <0.05) between the uncoated samples (S0 group) and all the other Ti (C, N) coated samples. Higher absorbance values were observed in all coated groups than in the control S0 group, where cell growth was statistically significantly lower. Conclusions: During incubation of endothelial cells with coated samples the number of cells was significantly bigger than the number with uncoated alloys. The best viability of cells was obtained from the S = 3 (with 51.94% at. Ti, 28.22% at. C and 19.84% at. N) group of samples. Ti (C, N) coatings may be applied as protective components on prosthetic elements made of base metal alloys.