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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.
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.
3
Content available Combustion Synthesis of Titanium Carbonitrides
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.
4
Content available remote Alumina composites with solid lubricant content
EN
Purpose: The aim of the study presented in this article is to determine the effect of the addition of solid lubricating substances on the selected properties of ceramic tool materials. The effect of tested lubricant additives on the density, porosity, Young’s modulus and Vickers hardness of Al2O3-based ceramics with Ti(C,N) was determined. Design/methodology/approach: Ceramic materials based on aluminium oxide with the addition of solid lubricating substances. Materials were obtained by uniaxial compression with the addition of sliding substances, then isostatically pressed, and dried. The sintering process was carried out at a temperature of 1750°C under high vacuum conditions. Density, Vickers hardness and Young’s modulus was determined for these materials. The materials were also subjected to tribological analysis. The results obtained were compared with the properties of ceramic material based on Al2O3 + 30 mass.% Ti(C,N), from which tool materials were made. Findings: The use of solid lubricating substances in the production of ceramic materials allowed a reduction in the coefficient of friction. Depending on the sliding additives used, the relative density values of individual materials were in the range of 85.3% to 92.3%. Young’s modulus values for these materials were in the range of 273 GPa to 343 GPa, and Vickers hardness in the range of 966 to 1373 HV1. The results of tribological analysis showed a coefficient of friction value for the base material of 0.51. For the other materials, the coefficient of friction values were in the range 0.28 to 0.41, the lowest value being for the material with the addition of BaZrO3. Practical implications: Ceramic materials with the addition of solid lubricating substances may be used in cutting tools. Study of the composition and production technology of such tools allows for the minimisation of the use of liquid cooling lubricants in the machining process and the achievement of higher cutting speeds. Originality/value: Ceramic materials intended for cutting tool blades were produced with the addition of materials of a layered structure or of high cleavage by free sintering. These materials were added to the structure, resulting in a reduced coefficient of friction, which was measured at between 55% and 75% of the coefficient of friction of the base material. The coefficient of friction was determined for friction pairs: ceramic material - high hardness steel ball.
PL
Badania określone tematem publikacji prowadzono w celu rozszerzenia własnej bazy danych o żużle z ok. 10 % zawartością TiO2. Badania prowadzono podobnie jak w pracach [1÷5], ale na nowszych urządzeniach. Otrzymane wyniki badań pozwoliły – po przeliczeniach według właściwego algorytmu – otrzymać statystyczne funkcje niezbędne dla opracowania modelu określającego czasowe powstawanie i wydzielanie się warstwy węglikoazotków tytanu na węglowych ścianach garu wielkiego pieca. Warstwa ta jest naturalną ochroną przed nadmiernym i szybkim zużyciem drogich materiałów ogniotrwałych.
EN
The research, determined with the subject of publication were carrying out for purpose of enlarging the own data base by slags of approx. 10 % TiO2 contents. The research were conducted in similar way like at publications [1÷5], but with using more modern equipments. The statistical functions necessary for elaboration of the model which determines the formation and nucleation of titanium carbonitride protection layer on blast-furnace graphite lining were obtained. The evaluations of protective layer were made according to algorithm described in the publication. This layer is natural protection for excessive and quick consumption of expensive graphite lining materials.
PL
Opracowano algorytm, model i program dotyczący kontroli tworzenia się warstwy ochronnej węglikoazotków tytanu na wyłożeniu węglowym wielkiego pieca. Wiele ośrodków hutniczych stosuje we wsadzie wielkopiecowym związki tytanu dla ww. celu, ale jak na razie nikt nie przedstawił tego działania technologicznego poprzez zintegrowany system kontroli m.in. tworzenia i powstawania tej warstwy. W niniejszej publikacji prezentuje się to w miarę szczegółowo wraz z symulacjami i weryfikacjami. Taki model może stać się częścią (podmodelem) zintegrowanego systemu – autorstwa ww. Autorów – zakupionego i zastosowanego w ArcellorMittal Steel.
EN
The algorithm, model and application referring to the monitoring of titanium carbonitride formation on the blast furnace graphite lining area were elaborated. Blast furnace charge containing titanium compounds is applied at many metallurgical plants, but at present any technological action such as integrated system of controlling and monitoring formation of the titanium carbonitride have been presented. In this publication the simulations and verifications this technological undertaking in detail manner are presented. This kind of model (submodel) may become the element of integrated system, which had been worked out by authors’of the paper, then purchased and applied to ArcellorMittalSteel.
EN
Purpose: The micro hardness properties of Titanium Carbonitride composite coated on SS-316 substrates were studied to achieve a desired harden surfaces. Design/methodology/approach: Hollow Cathode Discharge gun (HCD–gun) was employed for deposition of the Ti(C, N) on SS-316. The evaporated and ionized metal (Ti) was coated as an under layer with 0.5 ampere beam current and 100 volt bias voltage. The reactant nitrogen and methane gasses were fed through inlet in to the chamber containing Ti element to form Ti (C, N) matrix with an optimized ratio. Findings: In this work, Glow Discharge Optical emission Spectroscopy (GDOS) used for composition alanalysis of the content elements. On the bases of this operation it was revealed the existence of Ti, C, N elements, X-ray diffraction (XRD) technique was utilized to investigate films crystalline structure. The investigation showed that samples with different stoichiometry have a fcc structure with (111) plan of reflection. The atomic ratio of carbon and nitrogen were measured using energy dispersive X-ray (EDX) analysis. The optimized value was funned to be TiC0.87 N0.13. The atomic force microscopy (AFM) and scanning electronmicroscopy (SEM) were employed to study the films microstructure. A hardness of 3250 HV was obtained in the carbon content C/C+ N atomic ratio of 9 to 1 using a Vickers microhardness tester. Research limitations/implications: As the study was carried out on a limited surfaces, we shall endeavor further attempt on large area deposition. Practical implications: The tools coated in titanium accompanied by nitride and carbide has shown significant improvement. Good compatibility of Ti (C, N) compound makes these composite suitable in various technical and industrial applications. Originality/value: It may be remarked that, the hardness obtained in this work is very encouraging and therefore, it is convenient to regard this as a privileged step taken in tool manufacturing aspect.
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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