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EN
In the past few years, overhead copper transmission lines have been replaced by lightweight aluminum transmission lines to minimize the cost and prevent the sagging of heavier copper transmission lines. High strength aluminum alloys are used as the core of the overhead transmission lines because of the low strength of the conductor line. However, alloying copper with aluminum causes a reduction in electrical conductivity due to the solid solution of each component. Therefore, in this study, the authors attempt to study the effect of various Al/Cu ratios (9:1, 7:3, 5:5) to obtain a high strength Al-Cu alloy without a significant loss in its conductivity through powder metallurgy. Low-temperature extrusion of Al/Cu powder was done at 350ºC to minimize the alloying reactions. The as-extruded microstructure was analyzed and various phases (Cu9Al4, CuAl2) were determined. The tensile strength and electrical conductivity of different mixing ratios of Al and Cu powders were studied. The results suggest that the tensile strength of samples is improved considerably while the conductivity falls slightly but lies within the limits of applications.
EN
This study was conducted to investigate the capability of multi-pass friction stir processing (FSP) on microstructure modification and mechanical properties improvement of FVS0812 alloy. FSP was performed at different rotation speeds (1250, 1600, 2000, and 2500 rpm) and traverse speeds (8, 12, and 25 mm/min) for one, two, and four passes. According to the results, applying single-pass FSP at optimized conditions (i.e. 1600 rpm and 12 mm/min) enhanced the tensile strength, fracture strain, and microhardness of the alloy by about 1020, 1050, and 60%, respectively. This improvement can be mainly attributed to the intense breakage and uniform distribution of θ-Al13Fe4 and α-Al12(Fe,V)3Si intermetallics within the matrix, formation of ultrafine recrystallized grains, and elimination of casting defects. Increasing the number of FSP passes up to four slightly decreased the average size of intermetallic particles, but significantly improved their distribution within the matrix which led to 18 and 200% improvement of tensile strength and fracture strain of one-pass FSPed sample, respectively. The fractography results also revealed that multi-pass FSP has changed the fracture mode of Al-8.5Fe-1.3V-1.7Si alloy from low-energy brittle to a more ductile-dimple fracture.
EN
In this study, a screwed copper tube was cladded an aluminum tube by a new explosive cladding method. To study the modalities of the bonding interface, a light microscope was used to observe the bonding interface. To expose the weak position of the interface, a three-point bending test was conducted under extreme condition. Then the BSE (Backscattering Electron) images of the bent interfaces were obtained. Meanwhile, the EDS (Energy Disper-sive Spectrometry) analyses of the melted zone were performed. The results of the light microscopic observations show that there are four bonding modalities on the interface. They can be summarized to two bonding modalities: direct bonding and bonding with the melted zone. There are no macro cracks on the interface of the bent specimens, which represents a reliable joining generally. The elastic modulus of Al-Cu bimetallic tube along the axial direction is 85.2Gpa. The BSE images, the EDS analyses and the microhardness tests show the direct bonding with some characteristics of the micro wavy interface is a pretty nice bonding pattern. The melted zone composed of CuAl2 is a weak bonding pattern, which may affect the mechanical property of the joint.
EN
The effect of heat treatment at 903 K on microstructure and intermetallic compound growth in explosively welded A1050/Ti gr. 2/A1050 clad was presented in the paper. Growth kinetics of TiAl3 intermetallic layers formed at upper and lower interfaces of three-layered A1050/Ti gr. 2/A1050 was investigated. A new approach to definition of growth kinetics of TiAl3 intermetallic phase was discussed. It was established that the growth was solely governed by grain boundary diffusion at the upper interface. Change of the mechanism from grain boundary diffusion to volume diffusion was observed at the lower interface.
5
Content available remote Oxidation activation energy of titanium alloy based on TiAl(γ) intermetalic phase
EN
The present paper deals with the analysis of the course of oxidation of the cyclic Ti-46Al-7Nb-0.7Cr-0.1Si-0.2Ni alloy in a hot air atmosphere in the temperature range of 875-975°C. The constant rates of the oxidation were determined (separately for the first and second stages of oxidation) and the energy of oxidation activation of the tested alloy was established. It was discovered that the oxidation process of the Ti-46Al-7Nb-0,7Cr-0.1Si-0.2Ni alloy develops according to the parabolic correlation, and it is only possible to determine the apparent energy of oxidation activation.
EN
In this paper the results of the microscopic observations of the intermetallic AlFeMnSi phases crystals formed in the liquid hypo- and eutectic AlSi alloys containing transition metals 3.0 wt.% Fe and 0.1, 0.5 and 2.0 wt.% Mn were presented. The crystals morphology has been revealed on both polished and deep etched microsections. The different stages of the primary AlFeMnSi phases particles formation in the solidifying alloy and their final morphology were shown as influenced by cooling rate and alloy chemical composition.
EN
Purpose: The aim of this study was to examine the structural and mechanical properties of coatings formed on CuAl2 in-situ reinforced aluminium matrix composites (AMCs) by micro arc oxidation (MAO) process. AMC, which were fabricated by powder metallurgy method upon addition of copper powder into aluminium powder at different percentages (0%, 15 wt.% and 30 wt.%), were exposed to MAO after sintering at 550°C for 6 h. During sintering process CuAl2 type intermetallic was precipitated in the microstructure of copper containing compacts. MAO caused covering of the surfaces of AMCs with an oxide layer mostly consisting of mullite and alumina. Mechanical performance of the coatings were determined by hardness measurements and wear tests. In summary, the oxide layers formed on the AMCs exhibit a reduction in hardness and tribological performance with increasing copper content of the AMC.
PL
Utleniano stop na osnowie fazy międzymetalicznej Ni3Al w atmosferze powietrza i atmosferze powietrza z dodatkiem 1% SO2. Wytop stopu poddano obróbce plastycznej i wygrzewaniu rekrystalizującemu w 1000°C w atmosferze argonu. Proces utleniania prowadzono w temperaturze 900 i 1100oC przez 24 h. Stwierdzono, że na powierzchni próbek tworzy się dwuwarstwowa zgorzelina, zbudowana z NiO, Al2O3 oraz spinelu NiAl2O4. Wielkość przyrostu masy próbek zależy od składu atmosfery oraz temperatury. Dominującym procesem jest tworzenie się NiO. Stwierdzono, że niewielka ilość SO2 obniża szybkość korozji badanego stopu, co jest związane z reakcjami zachodzącymi na powierzchni zgorzeliny.
EN
An alloy based on the Ni3Al intermetallic phase matrix was oxidized in an atmosphere of air and in air containing 1% SO2. The alloy melt was subjected to plastic working and recrystallizing annealing at 1000°C under an atmosphere of argon. The oxidation process was carried out at 900 and 1100oC for 24 hours. It was found that two-layer scale composed of NiO, Al2O3 and NiAl2O4 spinel was formed on the sample surface. The rate of the sample weight increment depended on the composition of the atmosphere and temperature. The dominant process was the formation of NiO. Small amounts of SO2 were observed to reduce the corrosion rate in the investigated alloy, which was associated with reactions occurring on the surface of scale.
9
Content available remote The kinetics of corrosion of the FeAl intermetallic phase-based alloys
EN
Purpose:Purpose alloys on intermetallic phase matrix of iron and aluminium are considered the future materials for high-temperature applications as they are highly resistant to oxidation. Oxidized intermetallic alloy FeAl forms a protective alumina layer. The paper presents results of tests concerning kinetics of corrosion processes of alloy on intermetallic phase matrix FeAl of the composition Fe40Al5CrTiB after casting and plastic treatment with the use of co-extrusion method. The aim of this paper was to determine the resistance to high-temperature corrosion in atmosphere of air for alloy Fe40Al5Cr0.2TiB. Design/methodology/approach: Corrosion tests were conducted in temperatures 900, 950 and 1000°C in time 8 hours, kinetics of corrosion appointed on the thermogravimetry method. The condition of the surface of samples after tests was characterized with the use of electron scanning microscope and also the chemical composition of corrosion products was determined. Findings: Conducted tests have shown a high corrosion resistant alloy Fe40Al5CrTiB in comparison. The resulting graphs show the kinetics of corrosion processes on the parabolic character of the process of creating high-temperature corrosion products. Practical implications: The Al alloy have a high corrosion resistant with resistant conventional materials predestined to do work in high temperature in corrosion environment. Originality/value: The aim of this paper was to determine the resistance to high-temperature corrosion in atmosphere of air for alloy Fe40Al5Cr0.2TiB.
EN
In lead-free reflow soldering, the presence of voids should be taken into account. For this reason, the effect of the applied heating profiles was examined via the characterization of voids in galvanic and immersion Sn coatings. According to EU Directive 2002/95/EC, the screening of Pb element of reflow soldering (i.e. of electrical and electronic equipment) is necessary; and the practical implementation of this measurement is largely affected by the characteristics of the solder (i.e. the presence of voids and the inhomogeneity of the solder). Comparing the results of the above two coating methods, it was found that by chemical coating more voids were formed and the detected lead content was higher than for galvanic Sn. The standard deviation of Ag and Cu concentrations was mainly influenced by the appearance of large compounds in the second case, while with chemical coating, no large compounds were formed due to the elevated number of voids.
EN
Interfacial intermetallic compounds (IMC) play an important role in Sn-Cu lead-free soldering. The size and morphology of the intermetallic compounds formed between the lead-free solder and the Cu substrate have a significant effect on the mechanical strength of the solder joint. In the soldering process of Sn-Cu alloys, Cu6Sn5 intermetallic compounds are formed. The complex structural behaviour of Cu6Sn5 IMC is temperature- and composition-dependent and it is long since subject to scientific research. The Cu6Sn5 phase basically exists in two crystal structures: hexagonal η-Cu6Sn5 (at temperatures above 186°C) and monoclinic η’-Cu6Sn5 (at lower temperatures). In the presence of Ni in the solder, the η-η’ transformation does not occur, therefore, the η-Cu6Sn5 phase remains stable. In this study the role of Ni in the (Cu,Ni)6Sn5 intermetallic compound in Sn-Cu lead-free solders was examined. Sn-Cu alloys with different Cu content (0.5 to 1 mass%) were modified through Ni addition. The morphology of the intermetallic compounds of the modified Sn-Cu alloys was investigated by optical microscopy (OM) and scanning electron microscopy (SEM), the IMC phases were examined with X-ray diffraction method (XRD).
EN
The study describes the mechanism of structure formation in protective coating, growing on iron surface during hot-dip galvanizing. As a first stage of the galvanizing process, immediately after the iron sample has been dipped in galvanizing bath, a layer of frozen zinc is crystallizing on the sample surface. Next, as a result of isothermal solidification, an alloyed layer of the coating; composed of the sublayers of intermetallic Fe-Zn phases, is formed. At the initial stage of the existence of the alloyed layer, another layer, that of undercooled liquid, is formed on the surface of iron dipped in liquid zinc. As a result of peritectic reactions under metastable conditions, the individual phases are born, forming sublayers in the expected sequence of Γ1, δ and ζ.
PL
W pracy opisano mechanizm kształtowania się struktury powłoki ochronnej podczas cynkowania zanurzeniowego. Podczas pierwszego etapu procesu, zaraz po zanurzeniu wyrobu w ciekłym cynku, w pierwszej tworzy się na jego powierzchni kolejności warstwa namrożonego cynku. Warstwa ta roztapia się po pewnym czasie. Następnie w wyniku krystalizacji izotermicznej tworzy się warstwa stopowa powłoki, składająca się z cząstkowych warstw faz międzymetalicznych Fe-Zn. W początkowym okresie krystalizacji warstwy stopowej na powierzchni wyrobu wprowadzonego do ciekłego cynku powstaje warstwa przechłodzonej cieczy. W wyniku reakcji perytektycznych w warunkach metastabilnych kształtują się poszczególne fazy, tworząc podwarstwy faz w oczekiwanej kolejności: Γ1, δ oraz ζ.
13
EN
Influence of chemical composition and material structure on the abrasive wear of Ni3Al intermetallic alloy in loose abrasive was investigated in details. Boron, zirconium and chromium were used as the alloying elements. The alloys are made up of &gamma' or &gamma'+&gamma phases (single-phase, ordered matrix + disordered area). Grain size of the alloys was varied: 5, 20 and 45 &mi m. Abrasive were experiments were performed with T-07 tester (Norma company) in accordance to the GOST 23.2008-79 standard. Mechanism of surface layer damaging exposed to the loose abrasive was described on the basis of the obtained structural and topographical experiments. The results revealed that relative abrasive wear in loose abrasive is approximately same for all the investigated alloys with varied grain size.
EN
Theoretical investigations were performed to study on alloying stability, and electronic structure of (AlCu3, AlCu2Zr and AlZr3). The results show that the lattice parameters obtained after full relaxation of crystalline cells are consistent with experimental data, and these intermetallics have a strong alloying ability and structural stability due to the negative formation energies and the cohesive energies. The further analysis find out that single-crystal elastic constants at zero-pressure satisfy the requirement of mechanical stability for cubic crystals. The calculations on Poisson’s ratio show that AlCu3 is much more anisotropic than the other two intermetallics. In addition, calculations on densities of states indicates that the valence bonds of these intermetallics are attributed to the valence electrons of Cu 3d states for AlCu3, Cu 3d and Zr 4d states for AlCu2Zr, and Al 3s, Zr 5s and 4d states for AlZr3, respectively; in particular, the electronic structure of the AlZr3 shows the strongest hybridization.
PL
Przeprowadzono teoretyczne badania stabilności stopów i struktury elektronowej AlCu3. AlCu2Zr i AlZr3). Obliczania wskazują, że parametry sieci uzyskane po pełnej relaksacji komórek krystalicznych są zgodne z danymi eksperymentalnymi. Związki międzymetaliczne wykazują silną zdolność tworzenia stopów i stabilność strukturalną z powodu ujemnej energii tworzenia i energii spójności. Dalsze analizy wykazały, że stałe elastyczności pojedynczych kryształów przy zerowym ciśnieniu spełniają wymóg stabilności mechanicznej kryształów regularnych. Obliczenia współczynnika Poissona pokazują, że A1Cu3 posiada znacznie bardziej anizotropowe własności niż dwie pozostałe fazy międzymetaliczne. Ponadto, obliczenia gęstości stanów wskazują, że w tworzeniu faz międzymetalicznych biorą udział elektrony walencyjne odpowiednio: Cu na powłoce 3d dla A1Cu3. Cu na 3d i Zr na 4d dla AlCu2Zr. oraz Al na 3s, Zr na 5s i 4d dla AIZr3), w szczególności struktura elektronowa AlZr3) wykazuje najsilniejszą hybrydyzację.
EN
Purpose: The aim of this study was to determine the resistance of nickel and aluminium intermetallic phase-based coatings, modified with chromium and aluminum oxides, and to determine the hypothetical mechanism of these materials’ corrosion. Design/methodology/approach: The selected results of high temperature corrosion resistance of HVOF sprayed coatings with NiAl intermetallic phases are presented. The aggressive corrosion gas included: N2+9%O2+0.2% HCl+0.08%SO2. The temperature of cyclic corrosion test was 927 K and the exposure time was 500 h. The macro and microstructure of coatings after and before corrosion test were analyzed by optics and scanning microscopy. The thermodynamically diagrams and phase diagrams of corrosion products after the test are presented. The phase composition of corrosion products was determined by X-ray analysys. Findings: The proposed mechanism and growth of corrosion products on the NiAl(Cr)-Al2O3coatings are shown. The carried out tests allow the characterisation of the properties of coatings with NiAl phase, and supplement the state of knowledge in the scope of their high temperature corrosion resistance. Practical implications: The new elaborated coating can be applied in elevated temperature and aggressive environments for protection of water walls boilers or waste combustors. Originality/value: The elaboration of proposed mechanism of growth corrosion products on the NiAl(Cr)-Al2O3coating and the presentation of reaction during the corrosion process and degradation of coating.
EN
Alloys based on intermetallic phases from the Fe-Al system they belong to a group of high-temperature creep resisting materials of advantageous physicochemical and mechanical properties at an elevated and high temperature. In general, limitation on the capacity for a broad application of intermetals from the Fe-AI system, e.g. as an alternative to expensive alloy steels of specific properties, is their insufficient plasticity, which is a factor inhibiting further their development as constructional materiaIs. Under this study, research has been conducted on the capacity for forming alloys based on intermetallic phases from the Fe-AI system, via thermo-mechanical processing. In the present work, the possibility of forming FeAI-intermetallic-phase-based alloys in thermo-mechanical treatment (TMT) has been studied. After casting and annealing, alloy specimens were subjected to axial-symmetric compression in the GIeeble 3800 simulator in the range of 700-1200 C at 0.01, 0.1, 1.0, 10 S-1 strain rates. In order to analyze the proccsses which take place during deformation, the specimens after deformation were intensely cooled with water. Structural examination was carried out using light and electron microscopy. The impact of hot rolling process parameters on the structure of intermetallic-phase-based FeAI alloys and properties has bceen determined. The results will constitute the basis for modelling the structural changes in FeAI intermetallic alloy.
PL
W pracy oceniono możliwość kształtowania struktury i właściwości stopu na osnowie fazy międzymetalicznej z układu Fe-Al na drodze obróbki cieplno-plastycznej. Analizowano wpływ parametrów odkształcania na strukturę i technologiczną plastyczność stopu Fe-38% at. Al. Przeprowadzono próbę osiowosymetrycznego ściskania na symulatorze Gleeble 3800, dla zróżnicowanych parametrów odkształcania w zakresie temperatury 700-1200 C z prędkością odkształcenia [...]. Na podstawie analizy procesu ściskania próbki walcowano na walcarce kwarto i badano strukturę stopu po kolejnych etapach przetwarzania. Uzyskane wyniki badań będą stanowiły podstawę do opracowania technologii obróbki cieplno-plastycznej intermetalików z układu Fe-Al.
17
EN
The paper presents testing results of cyclic oxidation of Ti-46A1-7Nb based intermetallic alloy taking into account the effect of temperature, surface roughness and the cooling rate of temperature. Oxidation was carried out in air at the temperature between 875°C and 975°C. It was determined that in case of conventional preparation of the surface by grinding to low Ra value (in the research Ra~0,06žm), distinct scale chipping was present at the temperature of 950°C and above. The rise of surface roughness to R,:~6žm results in mass increase in case of oxidation in the temperature of 900°C, whereas it definitely reduces scale chipping in higher temperatures (925°C, 975°C). A slightly higher mass increase of the oxidised alloy including rise of the cooling rate were also determined.
PL
Przedstawiono wyniki badań nad możliwością wytwarzania materiałów kompozytowych o osnowie stopu aluminium EN AW6061 wzmacnianych cząstkami fazy międzymetalicznej Ti3Al w procesach metalurgii proszków i wyciskania na gorąco. Stwierdzono, że proces mechanicznego mielenia w zasadniczy sposób oddziałuje na własności materiałów proszkowych poprzez zmianę ich morfologii ze sferycznej, charakterystycznej dla stanu wyjściowego, w odkształconą plastycznie - płatkową, która następnie w powtarzających się procesach zgrzewania i pękania materiału umocnionego ponownie przyjmuje postać cząstek równoosiowych. Wykonane badania pozwoliły stwierdzić ponadto, że cząstki fazy międzymetalicznej odkształcają się plastycznie podobnie jak cząstki materiału osnowy, a zatem cząstki fazy międzymetalicznej Ti3Al w przeciwieństwie do cząstek ceramicznych nie wpływają na przyspieszenie procesu mechanicznego mielenia. Wytworzone materiały kompozytowe charakteryzują się równomiernym rozłożeniem rozdrobnionych cząstek wzmacniających, wpływającym na podwyższenie własności mechanicznych. W porównaniu do materiałów kompozytowych wytworzonych przez wyciskanie zmieszanych proszków materiałów wyjściowych, dla których dodatek cząstek wzmacniających powoduje wzrost twardości o 20-25 HV1, mechaniczne mielenie tych samych proszków z utworzeniem proszków kompozytowych powoduje dwukrotny wzrost twardości w odniesieniu do materiału osnowy. Rozdrobnienie mikrostruktury w połączeniu z dyspersyjnym umocnieniem materiału od cząstek wzmacniających prowadzi do znaczącej poprawy własności mechanicznych. Materiały kompozytowe z 15% wagowym udziałem cząstek Ti3Al osiągają wytrzymałość na rozciąganie Rm ok. 400 MPa.
EN
The present work investigates the production of aluminium EN AW6061 matrix composite materials reinforced with Ti3Al particles by powder metallurgy techniques and hot extrusion. The introduction of new reinforcements such as inter-metallics to aluminium alloys continues to be investigated in order to improve final behaviour of AMCs as well as to avoid some drawbacks of using ceramics as aluminium alloys reinforcements. The milling process has a big influence on the characteristics of powder materials, changing the spherical morphology of as-received powder (Fig. 1), during milling process to flattened one due to particle deformation (Fig. 2), followed by welding and fracturing particles of deformed and hardened enough which allows to receive equiaxial particles morphology again (Fig. 3). The investigation shows that so called brittle intermetallic particles yields to plastic deformation as good as ductile aluminium alloy particles. That indicates that in contrary to ceramics particle, the Ti3Al intermetallic powder can not play a role of the accelerator during mechanical milling. The mechanically milled and extruded composites show finer and better distribution of reinforcement particles what leads to better mechanical properties of obtained products (Fig. 5). The hardness increases twice in case of mechanically milled and only 20-25 HV1 for low energy mixed and hot extruded composites (Fig 6.) The finer microstructure increase mechanical properties of composites materials. The higher reinforcement content results in higher particles dispersion hardening (Fig 7). Composites reinforced with 15% of Ti3Al reach about 400 MPa UTS.
PL
Przedstawiono wyniki badań nad modyfikacją właściwości mechanicznych stopów na osnowie TiAl ([alfa]2+[gamma]). Jako surowce do badań posłużyły proszki: TiAl, produkcji Alfa Aesar, oraz TiB2, dostarczony przez Borax Consolidated Ltd. Czystość chemiczna użytych do eksperymentu proszków wynosiła 99,5%. Średnia wielkość cząstek TiAl wynosiła 12,7 žm oraz dla TiB2 1,6 žm (rys. 2). Z surowców proszkowych wykonano mieszaniny TiAl+x%TiB2 dla x = 0,10, 20, 30, 40% wag. drogą homogenizacji w młynku agatowym w alkoholu etylowym. Po wysuszeniu proszki granulowano, a następnie formowano metodą prasowania jednoosiowego pod ciśnieniem 20 MPa i doprasowywano izostatycznie pod ciśnieniem 120 MPa. Kompozyty otrzymane w wyniku spiekania charakteryzują się wysoką gęstością względną 95+98% (rys. 4) oraz twardością na poziomie 514 HV30 (rys. 5). Krytyczny współczynnik intensywności naprężeń osiągnął najwyższą wartość (K(IC) = 16 MPa x m1/2) dla kompozytu o udziale 10% wag. TiB2 (rys. 6). Mechanizm odpowiedzialny za wzmocnienie w badanych kompozytach związany jest z wyhamowaniem i odchylaniem pęknięć na cząstkach fazy ceramicznej (rys. 7).
EN
The study is concerned with improving the mechanical properties of TiAl ([alpha]2+[gamma]) by introducing ceramic particles of titanium diboride (TiB2) into its matrix. The material examined was prepared of the TiAl powder (manufactured by the Alfa Aesar) and the TiB2 powder (delivered by the Borax Consolidated Ltd), of a purity of 99.5%. The average size of the TiAl and TiB2 particles was 12.7 žm and 1.6 žm, respectively (Fig. 2). The powders were mixed by homogenizing in an agate mill filled with ethanol, to produce mixtures of various weight proportions: TiAl+xwt.%TiB2 with x = O, 10, 20, 30, 40 wt.%, by homogenizing in an agate mili filled with ethanol. After drying, the powders were granulated and subjectcd to uniaxial pressing under a load of 20 MPa and then again pressed under isostatic pressure of 120 MPa. The samples were sintered under a pressure of 35 MPa (HP) in an argon atmosphere at the temperature T = 1250°C for 1 h. After sintering, the composite shows a high relative density 95+98% (Fig. 4), hardness of 514 HV30 (Fig. 5) and a high stress intensity factor K(IC) = 16 MPa x m1/2 (value obtained for the TiAl+10wt.%TiB2 composite) (Fig. 6). The increased strength of the TiAl+10wt.%TiB2 composites can be attributed to the presence of the TiB2 ceramic grains. The hardening occurs as a result of the cracks formed in the ceramic phase particles being deflected and bridged (Fig. 7).
PL
W artykule przedstawiono wyniki badań spieków NiAl-TiC (15,30 i 50% obj. TiC) wytwarzanych w jednym procesie z mieszaniny proszków (niklu, aluminium i węglika tytanu wykorzystując metodę PPS (Pulse Plasma Sintering). Dla otrzymanych spieków przeprowadzono mikroskopowe obserwacje mikrostruktury oraz badania składu fazowego, chemicznego, mikrotwardości i gęstości. Stosując metodę fazowego PPS otrzymano z elementarnych proszków w czasie 900 s kompozyty NiAl-TiC o twardości od 510 HV30 (15% TiC) do 610 HV30 (50% TiC). Krytyczny współczynnik intensywności naprężeń zależy od zawartości TiC. W kompozytach o zawartości 15% TiC (510 HV30) nie stwierdzono kruchego pękania, dla kompozytu z zawartością 30% TiC KIC wynosi 9 Pa·m1/2 (550 HV30), a dla kompozytu o zawartości 50% TiC KIC = 7 Pa·m1/2 (610 HV30).
EN
The paper presents the results of examinations of the NiAl-TiC sinters (15, 30, 50 vol.% of TiC) produced of a mixture of the nickel, aluminum and titanium carbide powders in a single technological process, using the PPS method (Pulse Plasma Sintering). By subjecting the element powders to a PPS process for 900 s, we obtained the NiAl-TiC composites of a hardness ranging from 510 HV30 (15% TiC) to 610 HV30 (50% TiC). The critical value of the stress intesity factor in the sinteered materials depended on the amount of the dispersed TiC phase. When examined with a Vickers indenter under a load of 294 N, the compsite containing 15% of TiC showed no brittle cracking. In the composites with 30% TiC and 50% TiC contents, the value of KIc was 9 and 7 Pa·m1/2, respectively.
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