Wyniki wyszukiwania - Biblioteka Nauki

1

Influence of oxygen and humidity in atmospheres on friction and wear characteristics of TiN and TiC

100%

Yang L. , Yamamoto Y. , Hashimoto M.

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1999

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tom Vol. 4, no spec.

195-200

EN

The friction and wear characteristics of hot pressed TiN and TiC were examined in dry and wet atmospheres of oxygen and argon using a pin/disc type friction tester. In an atmosphere containing oxygen or humidity, for both TiN and TiC, a surface film composed mainly of titanium oxides and/or their hydrates were produced during runs. The formation of the surface films resulted in suppressing brittle fracture of the rubbing surfaces and reducing wear amount by a factor of 4 to 30. TiC has high ability to form TiO2 with low shear strength compared to TiN. In contrast, TiN is expected to keep a TiO2 film firmly through TiO formed on the TiN surface as the substrate of TiO2, since a lattice constant and interatomic distances of TiN are nearly equal to those of TiO. Therefore, a low friction of about 0.1 was attained with a combination of TiC pins and TiN disc.

2

Particulate Composites in the TZP-Carbide Systems

100%

Haberko K. , Pędzich Z.

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1999

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tom Vol. 47, nr 4

379-395

EN

The paper presents the results of investigations on particulate ceramic composites with the tetragonal zirconia polycrystalline (TZP) matrix. The WC, CrxCy and TiC particles were used as additives. The possibility of a chemical reaction in these systems was taken into account. Stresses caused by coefficient of thermal expansion mismatch of composite constituents were estimated. Phase composition and microstructure of the composite constituents were estimated. Phase composition and microstructure of the composites were described. Mechanical properties of the composites were measured and compared.

3

Influence of the laser modification of surface on properties and structure of magnesium alloys

84%

Dobrzański L. , Malara S. , Domagała J. , Tański T. , Gołombek K.

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2009

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tom Vol. 35, nr 2

95-100

EN

Purpose: The aim of this work was to improve the surface layer cast magnesium cast alloys by laser surface treatment, determine the laser treatment parameters and examine structure and properties. Design/methodology/approach: The laser treatment of magnesium alloys with alloying SiC and TiC powders with the particles size below 75 μ m and over 6.4 μm was carried out using a high power diode laser (HPDL). The resulting microstructure in the modified surface layer and was examinated using scanning electron microscopy. The X-ray qualitative and quantitative microanalysis and the analysis of a surface distribution of cast elements in the examined magnesium cast alloy was examined. The measurements of hardness and roughness of the modified surface layer was also studied. Findings: The alloyed region has a fine microstructure with hard carbide particles. Hardness of laser surface alloyed layer was dropped as compared to alloy without laser treatment. The roughness of layer surface increased after laser alloying and values are bigger for SiC alloying particles. Research limitations/implications: The investigations were conducted for cast magnesium alloys MCMgAl12Zn1 and MCMgAl9Zn1 and also TiC and SiC powders. One has used laser power in the range from 1.2 to 2.0 kW. Practical implications: The results obtained in this investigation were promising to compared other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd:YAG and CO₂ to improve the surface magnesium alloy by feeding the carbide particles. Originality/value: The value of this work is definition of the influence of laser treatment parameters on quality, microstructure and hardness of magnesium cast alloys surface layer.

4

Porównanie struktury i własności stali narzędziowej do pracy na gorąco stopowanej cząstkami TiC i WC

84%

Dobrzański L. A. , Labisz K. , Jonda E. , Klimpel A.

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2006

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tom R. 6, nr 21/1

117-124

PL

W pracy przedstawiono wyniki badań struktury oraz twardości stali narzędziowej do pracy na gorąco 32CrMoV12-28 stopowanej węglikiem wolframu oraz tytanu. Badania przeprowadzono przy użyciu nowoczesnego lasera dużej mocy HPDL. Stwierdzono zmiany struktury polegające na jej rozdrobnieniu, a także wzrost twardości w porównaniu do stali nie obrobionej laserowo. Określono wpływ parametrów obróbki laserowej na strukturę i twardość materiału.

EN

The laser treatment as a part of the new generation techniques applied in metal surface technology is discussed in this paper. Laser treatment is presented with remelting of hot work tool steel 32CrMoV12-28 with ceramic powders, especially TiC Titanium Carbide and WC Tungsten Carbide. The structure investigation, and improvement of mechanical properties, is the practical aim of this work, as well as improvement of hardness as a very important property for practical use.

5

Badania porównawcze napawanych plazmowo warstw niklowych z węglikami Ti i Cr

84%

Bober M. , Senkara J.

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2011

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tom R. 83, nr 9

32-37

PL

W artykule przedstawiono wyniki badań struktury kompozytowych powłok na osnowie stopu NiSi2B z dodatkiem węglików Ti i Cr, napawanych plazmowo z mieszaniny proszków na podłoża ze stali niskostopowej. Określono udział i rozmieszczenie fazy umacniającej w osnowie. Wykazano, iż odmienny charakter oddziaływania węglików Ti i Cr z ciekłym stopem Ni wpływa istotnie na proces formowania się napoin kompozytowych oraz na rozmieszczenie i udział cząstek fazy umacniającej w matrycy.

EN

The results of structure investigation of composite layers based on NiSi2B alloy with Cr and Ti carbides dopands are presented in the article. The layers were previously deposited by plasma powder transferred arc welding method onto low alloy steel substrates. The content and distribution of strengthening phase particles in the layer's matrix were determined. It was proved that formation of composite overlays along with refractory particles distribution are significantly affected by Ti and Cr carbides interaction of different character with liquid nickel alloy.

6

Laser surface treatment of magnesium alloy with WC and TiC powders using HPDL

84%

Dobrzański L. , Domagała J. , Tański T. , Klimpel A. , Janicki D.

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2008

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tom Vol. 28, nr 2

179-186

EN

Purpose: The aim of this work was to improve the surface layer cast magnesium alloy EN-MCMgAl6Zn1 by laser surface treatment. The purpose of this work was also to determine the laser treatment parameter. Design/methodology/approach: The laser treatment of an EN-MCMgAl6Zn1 magnesium alloy with alloying WC and also TiC powders was carried out using a high power diode laser (HPDL). The resulting microstructure in the modified surface layer was examinated using scanning electron microscopy. Phase composition was determined by the X-ray diffraction method using the XPert device. The measurements of microhardness of the modified surface layer was also studied. Findings: The alloyed region has a fine microstructure with hard carbide particles. Microhardness of laser surface alloyed layer with both TiC and WC particles was significantly improved as compared to alloy without laser treatment. Research limitations/implications: In this research two powders (WC and TiC) were used with the particle size over 5 µm This investigation presents different speed rates feed by one process laser power. Practical implications: The results obtained in this investigation were promising to compared other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd:YAG and CO2 to improve the surface magnesium alloy by feeding the carbide particles. Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten carbide and titanium carbide.

7

Napoiny na osnowie niklu z węglikiem tytanu - otrzymywanie i struktura

84%

Bober M. , Senkara J.

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2009

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tom z. 229

65-74

PL

W artykule przedstawiono struktury napoin kompozytowych o osnowie Ni umacnianych cząstkami TiC w zależności od natężenia prądu napawania. Powłoki te uzyskano poprzez napawanie plazmowe mieszaniny proszków na podłoża ze stali S355J0. Zaadoptowano program do analizy obrazów mikroskopowych MultiScanBase do określenia dystrybucji TiC w przekroju poprzecznym powłok oraz obliczono objętościowy udział cząstek fazy umacniającej osnowę. Przeprowadzono dyskusję czynników wpływających na wspomniany udział i dystrybucje TiC w osnowie powłok kompozytowych, a także analizowano rozkład mikrotwardości osnowy.

EN

Structure of composite Nickel - base surface layers strengthened by TiC particles are demonstrated in the article as function of welding current. The layers were deposited onto S355J0 type steel substrates by Plasma Powder Transferred Arc Welding method. Customized metallographic programme was applied to calculate volume fractions and distributions of TiC particles at the layers cross - sections. The impact of factors affecting above - mentioned behaviour of TiC particles was discussed along with micro - hardness distributions in the matrix of composite layers.

8

Characteristic of Mg-Al-Zn alloys after laser treatment

84%

Dobrzański L. A. , Domagała J. , Tański T. , Klimpel A. , Janicki D.

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2008

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tom Vol. 34, nr 2

69-74

EN

Purpose: The structure and the properties of casting magnesium alloy EN-MCMgAl3Zn1, EN-MCMgAl6Zn1, EN-MCMgAl9Zn1 and EN-MCMgAl12Zn1 after laser surface treatment are presented in this paper. The aim of this work was to improve the surface layer cast magnesium Mg-Al-Zn by melting and feeding of TiC particle on the surface. The purpose of this work was to determine the laser treatment parameter. Design/methodology/approach: The experiments were performed using high power diode laser. The laser treatment of an EN-MCMgAl3Zn1, EN-MCMgAl6Zn1, EN-MCMgAl9Zn1, EN-MCMgAl12Zn1 magnesium alloy with alloying TiC powders was carried out using a high power diode laser (HPDL). The resulting microstructure in the modified surface layer was examinated using scanning electron microscopy. Phase composition was determined by the X-ray diffraction method using the XPert device. The measurements of hardness of the modified surface layer was also studied. Findings: The alloyed region has a fine microstructure with hard carbide particles. Hardness of laser surface alloyed layer with TiC particles was significantly improved as compared to alloy without laser treatment for EN-MCMgAl3Zn1 and EN-MCMgAl6Zn1 alloys. Research limitations/implications: In this research one powder - TiC was used with the particle size over 6 µm. This investigation presents different speed rates feed and different laser power value for four type of magnesium alloys. Practical implications: The results obtained in this investigation were promising compared to other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd:YAG and CO2 to improve the surface magnesium alloy by feeding the carbide particles. Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using titanium carbide.

9

Structure changes and mechanical properties of laser alloyed magnesium cast alloys

67%

Dobrzański L. , Domagała J. , Malara S. , Tański T. , Kwaśny W.

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2009

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tom Vol. 35, nr 2

77-82

EN

Purpose: The aim of this work was to investigate structure and mechanical properties of the MCMgAl12Zn1 casting magnesium alloys after laser treatment. The laser treatment was carried out using a high power diode laser (HPDL). Design/methodology/approach: The laser processing of TiC, WC, SiC particles in MCMgAl12Zn1 and the resulted microstructures and properties are discussed in this paper. The resulting microstructure in the modified surface layer was examined. Phase composition was determined by the X-ray diffraction method using XPert device. The measurements of hardness after laser melt injection was also studied. Findings: Structure of the solidyifying material after laser alloying is characteristic with occurrences of areas with the diversified morphology, dependent on solidification rate of the magnesium alloys, is characteristic of structure of the solidified material after laser alloying. The MCMgAl12Zn1 casting magnesium alloys after laser alloying demonstrate similar hardness tests results, in reference to hardness of the alloys before their laser treatment. Research limitations/implications: In this research three powders (titanium carbide, tungsten carbide and silicon carbide) were used to reinforcing the surface of the MCMgAl12Zn1 casting magnesium alloys. Practical implications: High power diode laser can be used as an economical substitute for CO₂ and Nd:YAG lasers to modify the surface magnesium alloy by feeding the carbide particles. Originality/value: The originality of this work is applying of High Power Diode Laser for laser treatment of cast magnesium alloy consisting in fusion penetration of the hard particles of titanium, tungsten, and silicon carbides into the remelted surface layer of the alloy.

10

Laser surface treatment of cast magnesium alloys

67%

Dobrzański L. , Domagała J. , Tański T. , Klimpel A. , Janicki D.

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2009

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tom Vol. 35, nr 2

101-106

EN

Purpose: The goal of this work was to investigate influence of laser treatment on structure and properties MCMgAl3Zn1, MCMgAl6Zn1, MCMgAl9Zn1 and MCMgAl12Zn1 cast magnesium alloys. Design/methodology/approach: Tests were made on the experimental MCMgAl3Zn1 MCMgAl6Zn1 MCMgAl9Zn1 and MCMgAl12Zn1 casting magnesium alloys. Laser treatment was made using the Rofin DL020 HPDL high power diode laser in the argon shield gas cover with the technique of the continuous powder supply to the remelted pool area. Findings: Investigations of the surface layers carried out confirm that laser treatment of the surface layer of the Mg-Al-Zn casting magnesium alloys is feasible using the HPDL high power diode laser ensuring better properties compared to alloys properties after the regular heat treatment after employing the relevant process parameters. Occurrences were found based on the metallographic examinations of the remelted zone (RZ) and the heat affected zone (HAZ) in alloyed surface layer of the investigated casting magnesium alloy. Research limitations/implications: This investigation presents different laser power and in this research was used two powders, namely tungsten-, and titanium carbide. Practical implications: Reinforcing the surface of cast magnesium alloys by adding TiC and WC particles is such a possible way to achieve the possibilities of the laser melt injection process, which is a potential technique to produce a Metal-Matrix Composite (MMC) layer in the top layer of a metal workpiece. Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten- and titanium carbide.

11

Charakterystyka powłok TiC wytworzonych techniką zol-żel na ceramice narzędziowej.

67%

Biedunkiewicz A.

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2002

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tom R. XXIII, nr 5

364-367

PL

W artykule przedstawiono przegląd tytanoorganicznych kompleksów molekularnych stosowanych w charakterze prekursorów syntezy węglika tytanu. Metaloorganiczne kompleksy otwierają nowe drogi syntezy materiałów ceramicznych. Zaprezentowano opartą na metodzie zol-żel syntezę powłok Ti-C. Powłoki wytwarzano na płytkach wykonanych z węglików spiekanych i ceramiki tlenkowej. Próbki badano następującymi technikami analitycznymi: mikroskopia skaningowa, dyfrakcja rentgenowska i mikroanaliza rentgenowska.

EN

The review of titanoorganic molecular complexes used as precursor of TiC synthesis is presented. Metaloorganic complexes give new possibilities to ceramic materials' synthesis. The paper presents synthesis of Ti-C coatings on sintered Al2O3 and carbides (cutting tools) by sol-gel method. Samples were examined using the following analytical techniques: SEM, XRD, EDS, WDS.

12

Zastosowanie reaktywnego chemicznego osadzania z fazy gazowej (RCVD) do modyfikacji powierzchni włókien węglowych

67%

Olszówka-Myalska A. , Swadźba L. , Botor-Probierz A. , Janus T.

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2009

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tom R. 9, nr 1

19-23

PL

Zastosowano metodę reaktywnego osadzania z fazy gazowej RCVD do modyfikacji powierzchni włókien węglowych FT 300B w postaci rowingu. Dwa typy powłoki TiC oraz HfC wytworzono w reaktorach z kontrolowaną atmosferą reaktywną. Węglik tytanu powstał w wyniku reakcji węgla z powierzchni włókien z TiCl4, a węglik hafnu odpowiednio w wyniku reakcji z HfF4. Obserwacje metodami skaningowej mikroskopii elektronowej SEM wykazały powstanie powłok równomiernych, dobrze przylegających do podłoża o grubości 100-300 nm. Dzięki dyfuzyjnemu mechanizmowi tworzenia powłok nie wystąpił efekt mostkowania włókien. Skład fazowy włókien z powłokami scharakteryzowano metodą rentgenowskiej analizy fazowej XRD, która wykazała krystaliczną budowę powłok i obecność odpowiednio TiC oraz HfC. Uzyskanie powłok o wymaganej z punktu widzenia technologii kompozytów grubości i budowie wskazuje na celowość podjęcia prób ich aplikacji w kształtowaniu struktury połączenia w kompozytach umacnianych materiałami węglowymi.

EN

The method of reactive chemical vapour deposition (RCVD) was used for surface modification of carbon fibers FT 300B roving. Titanium carbide TiC and hafnium carbide HfC coatings were obtained in reactors with controlled reactive atmosphere. The TiC carbide was formed by the reaction between carbon and TiCl4. The parameters applicated during the deposition in hydrogen atmosphere were as follows: temperature of 1020°C, time range of 5-30 min. The titanium carbide coatings with thickness 100-300 nm were uniform and good adherent to the fibers. The bridging effect was not observed and XRD patterns showed the presence of crystalline TiC. During formation of hafnium carbide layer the HfF4 reacted with carbon fibers in argon atmosphere at the temperature of 1050°C. Similarly to TiC coatings SEM investigations showed that HfC coating was uniform and good adherent to the fibers. The thickness on the level of 100 nm was estimated and bridging effect was not observed also. Two crystalline phases were identified by XRD method. The hafnium carbide HfC as the main one and hafnium oxide HfO2 additionally. Results of presented experiments revealed that the reactive diffusion can be useable during surface modification of carbon fibers by carbides. The effect of bridging (typical for coating deposition by such method as CVD and electrochemical and chemical electroless deposition) is excluded. Coatings obtained by RCVD are uniform, good adherent and their thickness can be controlled on the nanometric level. The experiments of coated carbon fibers with different liquid alloys are necessary for verification their potential application in metal matrix composites.

13

Parameters of vacuum titanizing process as the factors changing growth kinetics of diffusion layers on steel surface.

59%

Kasprzycka E.

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1998

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tom R. XIX, nr 4

1015-1018

EN

Layers produced on carbon steel (0.90%C) during vacuum titanizing have been investigated. In particular, the influence of the pressure in furnance chamber is discussed. Titanium carbide layers have been obtained. Titanizing conducted at low pressure with a static rather than a dynamic vacuum during the holding period was found to be the most effective for maximizing the rate of growth of diffusion layers. It has been shown that the growth of titanized layers is controlled by the diffusion in the steel.

14

Structural investigations of Al-Fe-Ti alloys formed by mechanical alloying under various conditions.

51%

Krasnowski M. , Matyja H.

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1998

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tom R. XIX, nr 4

1163-1166

EN

There is increasing interest in the synthesis of aluminium-based alloys by mechanical alloying (MA). These materials possess a high specific strength and in high temperature applications, exhibit attractive mechanical properties. The aim of this work was to study the structural and phase transformations that take place during mechanical alloying of the ternary Al50Fe25Ti25 alloy in a high energy planetary ball mill. Two experiments were performed: one with an addition of ethanol and the other without any additional agent. The nanocrystalline composite powder, consisting of titanium carbide distributed in the Fe(Al) matrix was the final product of the process performed with the addition of ethanol. After milling without any agent an amorphous phase was observed to form. When this phase was then subjected to heating in a calorimeter the ternary phase tau2(Al2FeTi) and Fe(Al, Ti) solid solution appeared.