Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 225

Liczba wyników na stronie
first rewind previous Strona / 12 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  titanium alloy
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 12 next fast forward last
PL
W ostatnich latach obserwuje się znaczny wzrost użycia bezzałogowych statków powietrznych (BSP) w licznych zastosowaniach komercyjnych, a także wojskowych. Obecnie szacuje się, że na świecie istnieje przeszło 10 mln tego typu obiektów, wykorzystywanych od celów od hobbystycznych po profesjonalne, których wartość przekracza wiele milionów dolarów. BSP, zwane powszechnie dronami muszą cechować się małą masą i dużą sprawnością układu napędowego i zasilania, które pozwalają na długi czas nieprzerwanej pracy w powietrzu zwiększając obszar potencjalnych zastosowań. Jest to szczególnie istotne w przypadku obiektów latających używanych w zastosowaniach profesjonalnych. W zależności od zastosowania i liczności serii, do ich budowy wykorzystuje się wiele różnych materiałów w szczególności kompozytów. Jednakże bezzałogowe aparaty latające używane do celów militarnych, a także komercyjnych, np. w transporcie i rolnictwie muszą dodatkowo cechować się wytrzymałą i stabilną konstrukcją pozwalającą na przenoszenie dużych obciążeń. Z tej przyczyny coraz częściej do budowy BSP używa się stopów metali lekkich w szczególności aluminium, magnezu i tytanu. Ważnym argumentem przemawiającym za używaniem stopów metali lekkich są również względy ekologiczne gdyż niedostatecznie jeszcze są rozwinięta procesy recyklingu materiałów kompozytowych.
EN
In recent years, there has been a significant increase in the use of unmanned aerial vehicles(UAV) in numerous commercial as well as military applications. Currently, it is estimated that there are more than 10 million such objects in the world, used for purposes ranging from hobby to professional, with a value exceeding many millions of dollars. UAV, commonly referred to as drones, must be characterized by low weight and high efficiency of the propulsion and power systems that allow for long periods of continuous operation in the air increasing the area of potential applications. This is especially important for flying objects used in professional applications. Depending on the application and the number of series, many different materials are used for their construction, especially composites. However, unmanned aerial vehicles used for military as well as commercial purposes, such as transport and agriculture, must additionally feature a robust and stable design to carry heavy loads. For this reason, lightweight metal alloys, in particular aluminum, magnesium and titanium, are increasingly being used to build UAV. An important argument for the use of light alloys are also ecological considerations as recycling processes for composite materials are still underdeveloped.
EN
The paper presents an update of the recent literature on advances in machining of difficult to machine materials such as nickel and titanium-based alloys, and composites used in aeroengine and aerostructure applications. The review covers the following issues: advances in high-performance cooling techniques as cryogenic machining, minimum quantity lubrication, the combination of MQL and cryogenic cooling, and high-pressure lubricoolant supply and hybrid cutting processes – vibration assisted machining (both low and high frequency), laser, plasma and EDM assisted machining. Examples of applications in industrial processes are also given.
EN
Surface treatment, both mechanical, chemical and thermal causes a number of changes to the external structure of meterial details. The obtained properties are intended to improve the quality of material details made of a given alloy or pure metal. This paper presents the results of mechanical surface treatment to the thickness of the oxide layer after heat treatment of the TU6Al14V ELI alloy. The experiments were performed for a rod with a diameter of 5 mm cut into semicircular slices. The samples were mechanically activated by mechanical treatment of the surface: sandblasting with glass balls for 5 minutes, sanded with 40, 180, 220 and 800 grit sandpaper for 7.5 and 15 minutes. Using an optical microscope, the microstructure of the samples etched with Kroll's solution was assessed and the surface roughness parameters were measured. The next step was to carry out the heat treatment (at the temperature of 550 oC, for 5 hours), and then the roughness parameters and the thickness of the oxide layer were measured using a scanning microscope. The conducted research has shown that mechanical treatment of the surface resulting in an increase in surface development causes an increase in the thickness of the oxide layer formed during heat treatment. However, machining to reduce surface development, such as polishing, reduces the thickness of the oxide layer. The test results can be used to obtain the desired thickness of the oxide layer in the production of elements requiring increased resistance to wear or corrosion.
EN
The article presents the results of modelling the friction phenomenon using artificial neural networks and analysis of variance. The test material was composed of strip specimens made of 0.5-mm-thick alpha-beta Grade 5 (Ti-6Al-4V) titanium alloy sheet. A special tribotester was used in the tests to simulate the friction conditions between the punch and the sheet metal in the sheet metal forming process. A test called the strip drawing test has been conducted in conditions in which the sheet surface is lubricated with six environmentally friendly oils (palm, coconut, olive, sunflower, soybean and linseed). Based on the results of the strip drawing test, a regression model and an artificial neural network model were built to determine the complex interactions between the process parameters and the friction coefficient. A multilayer perceptron with one hidden layer and eight neurons in this layer showed the best fit to the training data. The network training was conducted using three algorithms, i.e. Levenberg-Marquardt, back propagation and quasi-Newton. Taking into consideration both the coefficient of determination R2 (0.962) and S.D. ratio (0.272), the best regression characteristics were presented by the network trained using the Levenberg-Marquardt algorithm. From the response surfaces of the quadratic regression model it was found that an increase in the density of lubricant at a specific pressure causes a reduction in the coefficient of friction. Low density and high kinematic viscosity of the oil leads to a high coefficient of friction.
EN
The article presents the process of designing a connecting rod and crankshaft made of titanium alloy Ti6Al4V in accordance with the assumed dimensions. The Engine unit will power a vehicle taking part in the Shell Eco-Marathon competition. The elements were subjected to FEM simulation for static and fatigue strength to check their trouble-free operation. The research has had positive effects, making further modification of the designed parts unnecessary. The energy needed to set in motion elements made of steel and Ti6Al4V alloy was compared, which results in a difference in fuel consumption.
PL
W niniejszej pracy przedstawiono analizę właściwości antykorozyjnych powłok silanowych osadzonych na tytanie Grade 2 i stopie tytanu Ti6Al4V. Do nałożenia powłok składających się z winylotrójmetoksysilanu (VTMS), etanolu (EtOH) oraz kwasu octowego (AcOH) wykorzystano metodę zanurzeniową. Przeanalizowano wpływ stężenia VTMS na odporność na korozję tytanu i jego stopu. Odporność na korozję nałożonych powłok analizowano w środowisku siarczanowym (pH=2) oraz w płynie Ringera (pH≈6), za pomocą krzywych potencjodynamicznych. Analizowano morfologię powierzchni i mikrostrukturę przy wykorzystaniu skaningowego mikroskopu elektronowego oraz mikroskopu optycznego oraz sprawdzono przyczepność powłok do podłoża przy pomocy taśmy ScotchTM.
EN
This paper presents the results of anti-corrosive properties of silane coatings deposited on titanium Grade 2 and the Ti6Al4V titanium alloy. The dip method was used to apply the coatings consisting of vinyltrimethoxysilane (VTMS), ethanol (EtOH) and acetic acid (AcOH). The influence of VTMS concentration on the corrosive properties of titanium and its alloy was analyzed. The protective properties of the applied coatings were analyzed in the sulphate environment (pH = 2) and in the Ringer’s liquid (pH≈6). The corrosion resistance of the produced coatings was assessed using potentiodynamic curves. Surface morphology and microstructure were analyzed using a scanning electron microscope and an optical microscope, and the adhesion of coatings to the substrate was checked using ScotchTM tape.
EN
Over the last few decades, titanium alloys have become an important ingredient in many industrial sectors. In fact, titanium with additional characteristics, such as: high strength, heat resistance, low thermal conductivity, light weight and biocompatibility are being more and more used. However, the machining of titanium products tends to result in a thermal oxidation process and the development of a coloured layer. Therefore, a research regarding the thermal oxidation phenomena and its prevention was conducted. In this regard, cutting and grinding processes were experimentally investigated. Subsequently, L-ascorbic acid, a substance used against food oxidation, was used as an agent against oxidation during grinding. The main conclusions of the current study are the following: (1) Causes leading to the thermal oxidation during cutting and grinding were defined, (2) Prevention against oxidation was established by using L-ascorbic acid and strong alkaline water solution, (3) Optimum density of the solution with L-ascorbic acid and strong alkaline water was only 7.5 wt. % for grinding.
8
Content available remote Studying the wear of titanium thread of aircraft fuel filter
EN
The article presents the tests that were conducted to examine the possibility of the fuel filter shank’s thread shearing under the impact of hydrostatic pressure. Increasedwear due to friction was confirmed on the threads of the titanium shanks that were tested, together with significantly reduced wear of the mating threads and steel sleeves. Shearing tests confirmed that to shear a thread that is worn to a degree similar to the threads that were tested, it is necessary to apply eight times more static pressure than the maximum pressure in the filter. A comparison of the shape of the coils of the thread that was subjected to the pressure test with the thread from the damaged filter demonstrated a significant difference in the wearing of these elements due to friction.
PL
W artykule przedstawiono przeprowadzone badania możliwości ścięcia gwintu trzonu z filtra paliwa pod wpływem działania ciśnienia hydrostatycznego. Potwierdzone zostało występowanie znacznego zużycia przez tarcie badanych gwintów tytanowych trzonów oraz wyraźnie mniejszego zużycia współpracujących z nimi gwintów stalowych tulejek. Próby ścinania wykazały, że do ścięcia gwintu zużytego w stopniu zbliżonym do badanych niezbędne jest zastosowanie 8-krotnie większego ciśnienia statycznego niż maksymalne ciśnienie występujące w filtrze. Porównanie kształtu nitek gwintu trzonów poddanych próbie ciśnieniowej z gwintem z filtra, który uległ awarii, wykazało znaczną różnicę w zużyciu tych elementów przez tarcie.
EN
The phase transformations during continuous cooling from the single phase β range in the Ti13Nb13Zr alloy have been analysed. Investigations were carried out by the dilatometric method using L78 R.I.T.A. dilatometer of the LINSEIS Company. The received results have been illustrated by selected dilatometric curves ΔL = f(T), (where: ΔL is the length change of the sample, T – temperature). On the basis of the curves, the temperature at which diffusion and non-diffusion transformations start and finish has been determined. The cooling curves was differentiated ΔL/T = f(T). Additionally, changes in the alloy microstructure during cooling down from the single phase β range have been analysed. After cooling from 780°C the diffusion martensitic transformation β → α” and probably massive transformation β → αM occur in the alloy cooling rate range from 160–10°C/s. It has been found that in the range of 5–0.05°C/s of the applied cooling rate, a diffusion β → α + β transformation is observed. Besides microstructure changes, dilatometric effects were also observed which corroborates the occurrence of phase transformation in the alloy. The obtained results may serve for the interpretation of phase transformations occurring in the Ti13Nb13Zr alloy during aging.
PL
Celem pracy była ocena kinetyki przemian fazowych zachodzących podczas ciągłego chłodzenia z różną szybkością stopu Ti13Nb13Zr z jednofazowego zakresu β. Na podstawie krzywych dylatometrycznych określono temperaturę, w której rozpoczynają się i kończą transformacje dyfuzyjne i niedyfuzyjne. Stwierdzono, że w zakresie zastosowanej szybkości chłodzenia (5–0,05°C/s) obserwuje się transformację dyfuzyjną β → α + β. Oprócz zmian mikrostruktury zaobserwowano również efekty dylatometryczne, które potwierdzają występowanie przemiany fazowej w stopie. Uzyskane wyniki mogą służyć do interpretacji przemian fazowych zachodzących w stopie Ti13Nb13Zr podczas s.
EN
The aim of the study was to indicate the influence of consolidation processes on microstructure and selected mechanical properties of powder metallurgy Ti-5Al-5Mo-5V-3Cr alloy, which was produced by blending of elemental powders method. Morphology of the mixture and its ingredients were examined using scanning electron microscopy. The consolidation of powders mixture was conducted using two approaches. The first consisted of the uniaxial hot pressing process, the second included two steps – uniaxial cold pressing process and sintering under argon protective atmosphere. Microstructural analysis was performed for both as-pressed compacts using light microscopy. Additionally, computed tomography studies were carried out, in order to examine the internal structure of compacts. Chosen mechanical properties, such as Vickers hardness and compression strength was also determined and compared. The conducted research proves that the proposed production method leads to obtain materials with no structural defects and relatively low porosity. Moreover, due to the proper selection of manufacturing parameters, favorable microstructures can be received, as well as mechanical properties, which are comparable to conventionally produced material with the corresponding chemical composition.
EN
This paper presents a study on anodizing titanium alloy Ti-6Al-7Nb in electrolyte of dilute sulfuric acid. The effects of the parameters – voltage, anodizing time, and electrode distance on the anodic film properties have been investigated. The anodic layers are found to become more compact with the increase of the applied voltage in the electrolytic cell. The microstructure, chemical element distribution and mechanical properties, i.e. microroughness and microhardness of the anodic coatings obtained at different operating conditions have been evaluated.
EN
This article proposes these of vibratory machining to Ti-6Al-4V titanium alloy as finishing treatment. Titanium alloy was used in the aerospace industry, military, metallurgical, automotive and medical processes, extreme sports and other. The three-level three-factor Box-Behnken experiment examined the influence of machining time of vibratory machining, the type of mass finishing media used and the initial state of the surface layer on the mass loss, geometric structure of the surface, micro hardness and the optimal process parameters were determined. Considerations were given the surfaces after milling, after cutting with a band saw and after the sanding process. The experiment used three types of mass finishing media: polyester, porcelain and metal. Duration of vibratory machining treatment was assumed to be 20, 40, 60 minutes. The form profiles before and after vibratory machining were determined with the Talysurf CCI Lite - Taylor Hobson optical profiler. Future tests should concern research to carry out tests using abrasive pastes with a larger granulation of abrasive grains, to carry out tests for longer processing times and to determine the time after which the parameters of geometrical structure of the surface change is unnoticeable.
EN
Mechanical behavior of a multifunctional titanium alloy Gum Metal was investigated by conducting tensile tests at various strain rates and applying digital image correlation (DIC) technique. Stress–strain curves confirmed low Young’s modulus and high strength of the alloy. The determined values of yield strength had a tendency to increase, whereas the elongation to the specimen rupture tended to decrease with increasing strain rate. True stress versus strain curves were analyzed using selected lengths of virtual extensometer (VE) placed in the strain localization area. When the initial length of the VE was the same as the gauge length, work hardening was observed macroscopically at lower strain rates, and a softening was seen at higher strain rates. However, the softening effect was not observed at the shorter VE lengths. Evolution of the Hencky strain and rate of deformation tensor component fields were analyzed for various strain rates at selected stages of Gum Metal load-ing. The DIC analysis demonstrated that for lower strain rates the deformation is macroscopically uniform up to the higher average Hencky strains, whereas for higher strain rates the strain localization occurs at the lower average Hencky strains of the deformation process and takes place in the smaller area. It was also found that for all strain rates applied, the maximal values of Hencky strain immediately before rupture of Gum Metal samples were similar for each of the applied strain rates, and the maximal local values of deformation rate were two orders higher when compared to applied average strain rate values.
EN
Titanium super alloys are often used in the chemical and aerospace industries, especially because of financial savings, resulting primarily from cheaper operation of equipment. Machinability of titanium alloys is more difficult than that of other metals. In addition, the low thermal conductivity causes the alloy to stick to the cutting edge of the cutting tool, thereby causing it to become dull faster. The article deals with the experimental evaluation of cutting forces and the design of suitable cutting parameters for the machining of the UNS R56260 titanium alloy with high-feed milling technology. Testing was carried out in climb and conventional milling under different cutting conditions. The cutting components of forces Fx, Fy, Fz were measured and evaluated. The results of the measurements were processed into a graphical form and suitable cutting conditions were designed in terms of the acting cutting forces.
PL
Wiercenie materiałów ciągliwych, do których zalicza się Ti6Al4V, często wiąże się z niewystarczającym odprowadzeniem wiórów, co prowadzi do wystąpienia zakłóceń procesu obróbki. Wióry powstające w trakcie procesu wiercenia materiałów plastycznych są ciągliwe i mają skłonność do gromadzenia się w rowkach wiórowych narzędzia. Takie gromadzenie się wiórów może skutkować zarysowaniami powierzchni otworu, przyklejeniami materiału do narzędzia skrawającego, a także do przyśpieszonego zużycia ostrza skrawającego. W niniejszym artykule przedstawiono wyniki badań uzyskane w procesie wiercenia stopu tytanu Ti6Al4V w aspekcie dokładności wymiarowo-kształtowej uzyskanych otworów. Obróbkę prowadzono bez chłodziwa (na sucho) przy różnych zestawach parametrów skrawania. W ramach badań monitorowano siłę posuwową i moment skrawania, dokładność kształtowo-wymiarową, jakość powierzchni otworu oraz kształt wiórów. Wyniki badań pokazują, że zarówno jakość otworu, jak i jego dokładność wymiarowo-kształtową można poprawić przez odpowiedni dobór parametrów skrawania. Ponadto, obserwacja powierzchni na wyjściu narzędzia z materiału wskazywała na występowanie odkształceń plastycznych (zadziory) związanych z parametrami skrawania. Wyniki eksperymentu wykazały także, że na kształt i wielkość zadziorów istotny wpływ ma prędkość posuwu.
EN
The drilling of ductile materials, such as Ti6Al4V, is often associated with insufficient chip evacuation, resulting in disturbances in the machining process. Chips formed during the drilling process of plastic materials are ductile and tend to accumulate in the chip flutes of the tool. Such chip formation may result in scratches on the hole surface, sticking the material to the cutting tool, and also on accelerated wear of the cutting edge. This article presents the analysis of the drilling process and assessment of the quality of the hole after drilling Ti6Al4V titanium alloy without coolant at various processing parameters. As part of the research, the feed force and cutting moment were monitored, the shape and dimensional accuracy and the quality of the hole surface and the shape of the chips. The test results show that the hole quality can be improved by appropriate selection of cutting parameters. Observation of the surface at the exit of the tool from the material indicated plastic deformation (burrs) in different cutting conditions. The results of the experiment also showed that the shape and size of burrs is strongly influenced by the feed speed.
EN
The study addresses the results concerning the laser welding technology of the titanium circulatory support blood pump Religa Heart ROT. Pulse laser welding parameters were determined and selected. The influence of the pulse welding parameters and other conditions of welding process on the magnetic induction distribution of the mechanical circulatory support blood pump was investigated.
PL
W artykule przedstawiono wyniki badań procesu spawania laserowego tytanowego wirnika pompy wspomagania serca Religa Heart ROT. Określono parametry spawania laserowego w trybie impulsowym zapewniające uzyskanie odpowiedniego wtopienia oraz ich wpływ na zmiany indukcyjności magnesów neodymowych znajdujących się wewnątrz wirnika pompy. Opracowano parametry technologiczne spawania laserowego zapewniające brak zmian indukcyjności wirnika pompy po spawaniu.
EN
In modern machining industry, the concept of process optimization has gained widespread recognition. FEM simulations are commonly used for the optimization of machining operations, allowing for a proper choice of tool geometry and process parameters to obtain results that are in accordance with end user criteria. However, one has to be wary that a good agreement of experimental and simulation results is mandatory if the simulation is to be used as a basis for optimization of a real-life process. Therefore, a proper choice of constitutive model parameters is vital. Those parameter values are dependent on many variables. Constitutive model parameter values are determined experimentally – therefore, they are accurate only for the conditions (temperature, strain rate etc.) under which the experiment was performed. The alteration, or optimization of model parameters is necessary if cutting and experiment conditions differ, if one wishes to obtain applicable results. In this work, the authors aim to present a method of optimizing the Johnson–Cook constitutive model parameters to obtain a better fit with experimental data.
EN
This paper presents a multi-factorial approach to the tool wear evolution when machining Ti6Al4V titanium alloy using high temperature resistant AlTiN coated cutting tools. Machining conditions were selected based on the technological database of machining titanium alloys in aircraft plants. The main novelty of this study is that tool wear progress within the tool life of about 20 min is assessed integrally in terms of mechanical, thermal and tribological process outputs such as cutting forces, cutting energy and cutting temperature. Moreover, the specific cutting energy (SCE), thermal softening effect and friction coefficient (CoF) were determined when recording tool wear curves. Some important research findings concerns distinguishing the three characteristic wear periods with distinctly different values of SCE and CoF. In particular, it was revealed that the formation of ceramic protective layer (CPL) on the AlTiN deposited coating influences friction and the tool wear mechanism.
PL
W artykule przedstawiono wieloczynnikowe podejście do ewolucji zużycia narzędzi podczas obróbki stopu tytanu Ti6Al4V przy użyciu narzędzi skrawających powlekanych, odporną na wysoką temperaturę, powłoką narzędziową AlTiN. Warunki obróbki zostały ustalone w oparciu o technologiczną bazę obróbki stopów tytanu stosowaną w przemyśle lotniczym. Główną nowością w ocenie przedstawionych badań jest to, że postęp zużycia narzędzia w okresie jego trwałości rzędu 20 minut jest oceniany integralnie, głównie pod względem mechanicznych, termicznych i trybologicznych efektów procesu skrawania, takich jak siły skrawania, energia i temperatura skrawania. Ponadto wyznaczono, adekwatne do zarejestrowanych krzywych zużycia narzędzia, wartości energii właściwej skrawania (EWS), zmiękczenia termicznego i współczynnika tarcia (WT). Niektóre ważne ustalenia badawcze dotyczą rozróżnienia trzech charakterystycznych okresów zużycia z wyraźnie różnymi wartościami EWS i WT. W szczególności okazało się, że utworzenie ceramicznej warstwy ochronnej (CWO) na narzędziowej powłoce z AlTiN wpływa na tarcie i mechanizm zużycia narzędzia.
EN
Purpose: The purpose of this article is discussing the methods of determining the surface roughness of the Ti-6Al-4V ELI titanium alloy obtained after longitudinal turning. The method of determining the mathematical model used for determining the Rz roughness parameter and then the results obtained were compared with values measured and calculated on the basis of equations available in the literature. Design/methodology/approach: The mathematical model in the form of multiple regression function of exponential polynomial was determined using the algorithm of the acceptance and rejection method. The data for calculations was obtained by measuring the surface roughness after turning with different machining parameter values. Findings: A mathematical model was elaborated in the form of a multiple regression function, enabling calculation of the Rz parameter describing the Ti-6Al-4V ELI titanium alloy surface roughness after longitudinal turning. The verification of the dependence obtained confirmed its accuracy. Research limitations/implications: Further research should encompass other values of machining plate geometry, as well as other types of cooling and lubricating fluids and method of applying them. Practical implications: The mathematical model can be helpful when choosing the conditions in which the turning process will be carried out. It also constitutes a basis for further optimisation of that process. Originality/value: The results of this research are a novelty on a worldwide scale. No research of this type has been conducted with regard to analyses and optimisation of longitudinal turning of the Ti-6Al-4V ELI titanium alloy.
EN
The paper presents the results of a study investigating the effect of slide burnishing on the surface roughness, surface layer microhardness and fatigue life of Ti6Al2Mo2Cr titanium alloy parts. The burnishing process was performed with the use of a diamond tip tool. Different machining fluids were used as machining media. Prior to burnishing, the samples were subjected to turning. The burnishing process led to reduced surface roughness (average roughness Ra decreased by 3.5 times and roughness Rz decreased by 2.5 times) as well as increased surface layer microhardness (microhardness maximum increase by 12%) and fatigue life of the tested parts. A relationship between the machining medium and the burnishing effects was also observed. The addition of a surface-active polymethyl methacrylate solution to the machining medium led to an increase in the surface layer microhardness and fatigue life of the workpiece.
first rewind previous Strona / 12 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.