W artykule przedstawiono badania dotyczące wpływu powłok Cr, Ti, Cr/Ti na właściwości tribologiczne stali X38CrMo16 stosowanej, m.in. do wytwarzania form wtryskowych. Powłoki uzyskano techniką fizycznego osadzania z fazy gazowej PVD. Zwilżalność powierzchni określono za pomocą tensjometru optycznego przy użyciu metody kropli siedzącej. Testy tribologiczne przeprowadzono za pomocą tribometru TRB3 w skojarzeniu trącym kula-tarcza w ruchu posuwisto-zwrotnym w warunkach tarcia technicznie suchego. Przeciwpróbkę w badanych węzłach tarcia stanowiła kulka ze stali 100Cr6. Po testach tarciowo-zużyciowych próbki poddano obserwacjom mikroskopowym. Wartości kątów zwilżania wodą demineralizowaną wskazały, że wszystkie badane powierzchnie charakteryzują się dobrą zwilżalnością. Na podstawie uzyskanych wyników badań tribologicznych stwierdzono, że powłoki charakteryzowały się mniejszymi oporami ruchu oraz zużyciem w porównaniu do stali X38CrMo16, przy czym najmniejsze wartości uzyskano dla powłoki Cr.
EN
In this paper the influence of Cr, Ti, Cr/Ti coatings on tribological properties of X38CrMo16 steel used, among others, for the production of injection molds were examined. The coatings were obtained by the PVD gas phase physical deposition technique. The wettability of the surface was determined by an optical strain gauge using the sedentary drop method. Tribological tests were performed with the TRB3 tribometer in reciprocating ball-disc friction combination under technically dry friction conditions . The counter-sample in the friction nodes tested was a 100Cr6 steel ball. After the friction and wear tests, the samples were subjected to microscopic observations. The values of the wetting angles with demineralized water indicated that all tested surfaces are characterized by good wettability. Based on the resuIts of tribological tests, it was found that the coatings were characterized by Iower resistance to movement and wear with respect to X38CrMo16 steel, with the lowest values obtained for the coating Cr.
Titanium and its alloys represent a special class of materials. A density of 4.81 g/cm³, a tensile strength of over 1,200 MPa, a fatigue strength greater than that of steel, a low modulus of elasticity and its self-passivating, inert surface make titanium an ideal material for lightweight structures in aerospace, marine applications, the chemical industry and medical implants. Although titanium is inert in its oxidised state, its nascent surface created in machining reacts with almost everything in its environment, including the tool. Moreover, its poor thermal conductivity results in high thermal stress on the tools. Overall, these properties lead to high wear rates and result in the requirement for finding a particularised solution for processes such as milling that involve the need to overcome such challenges. Such processes therefore require lubricants with well-selected performance additives. However, most of these performance additives are based on mineral oil and thus come from a non-renewable resource. In the presented work, environmental-friendly alternatives to conventional mineral oil-based performance additives were investigated. Due to the working mechanisms of performance additives in machining, this work focusses on sulphur- and phosphorus-containing polysaccharides and proteins from microalgae. It has been successfully shown that lubricants using extracts from microalgae as performance additives can be used for high-speed milling (HSC) of TiAl6V4. The investigated extracts were able to reach the performance level of conventional additives in terms of tool lifetime and wear. The results obtained show that appropriate alternatives to mineral oil-based additives exist from renewable raw-material sources.
The paper presents the results of experimental studies, including tribological tests of silicone-based composites with additions of hexagonal boron nitride (hBN) and titanium (Ti). The tests were conducted on a Bruker UMT2 tribotester and using a pin-on-disk setup developed by the authors, without a lubricating medium, and they employed a steel ball made of 100Cr6 steel and a sample made of the composite. During the tests, the products were not removed from the contact area. The paper analyzes the influence of additives on the tribological properties of the composite, i.e., the coefficient of friction (COF) as a function of distance and the wear of the tested samples. In the case of samples containing hBN, the COF decreases with an increase in its content. After reaching a volumetric percentage concentration of 20%, it begins to stabilize with the increase in mass loss. The profiles of COF changes as a function of distance for samples with different additive contents are comparable. The self-lubricating properties of hBN have been confirmed. The addition of Ti reduces the COF value, which decreases with the increase in the Ti content. Samples with a mass percentage concentration exceeding 100% of the Ti content have a COF value equal to the initial value for silicone. Thecomposite containing hBN has a lower COF value than samples with the Ti addition, and the wear tracks on their surface are narrower and shallower. The article is published in connection with the Autumn Tribology School.
PL
W pracy zostały przedstawione wyniki badań doświadczalnych obejmujących testy tribologiczne kom pozytów na osnowie silikonowej z dodatkami heksagonalnego azotku boru (hBN) i tytanu (Ti). Badania przeprowadzono na tribotesterze Bruker UMT2 i stanowisku autorskim typu Pin-on-disk bez stosowania medium smarującego w skojarzeniu kulki stalowej wykonanej ze stali 100Cr6 i próbki wykonanej z kompozytu. W trakcie prowadzenia badań produkty nie były usuwane ze strefy ruchu. W pracy analizowano wpływ dodatków na właściwości tribologiczne kompozytu, tj. wyznaczono współczynnik tarcia (COF) w funkcji drogi oraz zużycie badanych próbek. W przypadku próbek zawierających hBN wartość COF maleje wraz ze wzrostem jego zawartości. Po osiągnięciu stężenia procentowego objętościowego o wartości 20% zaczyna się stabilizować wraz ze wzrostem ubytku masy. Przebiegi zmian COF w funkcji drogi dla próbek o różnej zawartości dodatku są porównywalne. Właściwości samosmarujące hBN zostały potwierdzone. Dodatek Ti powoduje obniżenie wartości COF, która maleje wraz ze wzrostem zawartości dodatku Ti. Próbki o stężeniu procentowym masowym przekraczającym 100% zawartości Ti posiadają wartość COF równą początkowej dla silikonu. Kompozyt zawierający hBN charakteryzuje się mniejszą wartością COF niż próbki z dodatkiem Ti, a ścieżki powstałe na ich powierzchni są węższe i płytsze. Artykuł publikowany w związku z Jesienną Szkołą Tribologiczną.
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The present paper is related to the problems of production of car window accessories from the modified foundry alloys of zinc. The material includes the results of the conducted industrial tests and developmental work. The range of the requirements for components and the properties of standardized materials were discussed. The innovative method for titanium alloying in the zinc ZnAI4Cu3 alloy was developed and described. The casts made from innovative materials, as produced in the demonstration line were subjected to a series of endurance (fatigue) tests.
PL
Artykuł dotyczy zagadnienia wytwarzania pozycjonerów osprzętu szyb samochodowych ze zmodyfikowanych stopów odlewniczych cynku. Materiał obejmuje wyniki przeprowadzonych badań przemysłowych oraz prac rozwojowych. Przedstawiono zakres wymagań stawianych komponentom oraz właściwości znormalizowanych materiałów. Opracowano oraz opisano nowatorską metodę stopowania tytanu w stopie cynku ZnAl4Cu3. Wytworzone w ramach linii demonstracyjnej odlewy z innowacyjnego materiału podano szeregowi badań oraz testom zmęczeniowym.
The specific requirements of installations used in the chemical and petrochemical industries require materials with high corrosion resistance and adequate strength. Materials with these characteristics can be obtained by explosive cladding technology. Results of studies of the microstructure of titanium-austenitic steel 304L bimetallic joints in the welded and heat-treated condition are presented. Applications for this type of material include heat exchanger tube surfaces exposed to aggressive environments with high cyclical mechanical loads. The joints were tested using an optical microscope and a scanning electron microscopy. Heat treatment has contributed to a decrease in microhardness near the joint, which demonstrates a reduction in the strain hardening in this area.
PL
Szczególne wymagania instalacji stosowanych w przemyśle chemicznym i petrochemicznym powodują konieczność stosowania materiałów o dużej odporności korozyjnej oraz odpowiedniej wytrzymałości. Materiały spełniające te wymagania można wytworzyć technologią platerowania wybuchowego. W pracy przedstawiono wyniki badań mikrostruktury złączy bimetalicznych tytan-stal austenityczna 304L w stanie po zgrzewaniu i po obróbce cieplnej. Aplikacją tego typu materiałów są m.in. ściany sitowe wymienników ciepła, które narażone są na pracę w agresywnym środowisku, przy wysokich cyklicznych obciążeniach mechanicznych. Złącza badano z wykorzystaniem mikroskopu świetlnego oraz skaningowej mikroskopii elektronowej. Obróbka cieplna przyczyniła się do spadku mikrotwardości w pobliżu złącza, co świadczy o redukcji strefy umocnienia występującej w tym obszarze.
The aim of the study was the determination the effect of foliar application of growth regulator containing Ti (Tytanit®), on Lolium multiflorum morphometry, photosynthetic activity, chlorophyll content and chemical composition of dry matter. A pot experiment was carried out in a plant breeding room of Siedlce University, Poland, in 2019. The experimental units were as follows: I) control - plants sprayed with distilled water; II) plants sprayed with 0.02% Tytanit concentration; III) plants sprayed with 0.04% Tytanit concentration; IV) plants sprayed with 0.06% Tytanit concentration. The following parameters were determined: the shoots number, the number and the length of leaf blades, the length of roots, the dry weight of roots, the dry weight of plants per pot and the content of chlorophyll a and b in leaf blades. In addition, maximum and actual efficiency of the leaf photosystem, photochemical and non-photochemical quenching coefficients and the content of total protein, crude fibre, monosaccharides, crude fat, crude ash, Ca, Mg, P, K and the ratio of K/(Ca + Mg), and Ca/P in the dry matter of plants were determined. Used in controlled conditions, the regulator contributed to the growth of most morphological characteristics, improved photosynthetic activity, increased the concentration of chlorophyll a and b, and the content of total protein, monosaccharides, calcium and magnesium, at the same time expanding ionic ratios.
The aim of the presented study is to evaluate the influence of laser alloying with chromium and titanium on the surface layer microstructure and abrasive wear resistance of grey iron parts. A coulter flap was chosen as the object of this investigation. To produce the alloyed layer on the area of the flap that is the most exposed to wear, a diode laser was used as the heat source. The investigation demonstrated that laser alloying with chromium and titanium can increase the wear resistance of components working in abrasive conditions. A smaller mass loss after the wear tests in abrasive conditions of soil could be expected. The laser alloyed layer (with a depth of approx. 400 μm) was characterized by a martensite microstructure (mainly), homogenous morphology and fine grains. A fivefold increase in hardness (approximately 1050HV) in comparison to the hardness of the base material and twofold in comparison to the original ledeburitic surface layer of the coulter flap was noted. Some changes after laser alloying in the surface stereometry were observed (a decrease in the roughness parameters is possible). The roughness parameter values after the wear test decreased in the case of the original and alloyed coulter flaps..
Purpose: Additive manufacturing (AM) research needs new alloys to grow and offer new functionalities. This paper presents a novel powder production method by means of ultrasonic atomisation (UA). Powders for AM can be obtained from gas atomisation (GA) and a comparative study of UA- vs GA-made powders were carried out. To UA explain the pros & cons more clearly, a summary of the processes was added, along with the analysis of the droplet formation physics. Design/methodology/approach: Ultrasonic atomization (UA) with melting raw material by an electric arc. Characterisation of the powders: particle size distribution (PSD), density, and flowability were carried out. Other parameters, such as microstructure, deviation in the chemical composition and powder surface morphology, were also investigated. Findings: The results showed that the UA powder has a finer average particle size with a narrower statistical distribution of particles than those made by the GA method. Because the UA powder has a higher sphericity and lower porosity, Generally, UA offers better-quality powders in terms of properties such as higher tap density, better flowability and low oxygen content. Research limitations/implications: As an example of semi-industrial scale application of the UA system, the Ti6Al4V and TiAl powders were produced after remelting the wire. The UA system is commercially available for processing any metallic material. Practical implications: The test campaign results showed that the Ti6Al4V powder produced by the ultrasonic atomisation has a similar or better quality as those available from large-scale gas atomisation plants. Originality/value: The new method of UA powder production was analysed in terms of key powder parameters. The properties of the titanium-based powder produced this way were analysed with a view to future applications.
Celem pracy było zwrócenie uwagi na możliwość wykorzystania popiołów lotnych ze spalania węgla kamiennego jako źródła koncentratów tytanu. Zrealizowane prace badawcze miały na celu określenie warunków obróbki wstępnej popiołów lotnych w procesie alkalicznej aktywacji termicznej za pomocą węglanu sodu i ich wpływu na wydzielania związków tytanu w procesach hydrometalurgicznej obróbki. Proces przeprowadzono dla mieszanek popiołu i węglanu sodu w stosunku wagowym 1 do 1,1. Otrzymane mieszaniny ogrzewano przez 1 godzinę w temperaturze 973K, 1023K i 1083K. Po ostudzeniu i rozdrobnieniu ługowano otrzymaną pozostałość poreakcyjną za pomocą kwasu chlorowodorowego i azotowego (V). Wyniki analizy chemicznej i skaningowej analizy mikroskopowej wraz z analizą EDS i analizą rentgenowską wykorzystano do określenia właściwości chemicznych i fizycznych badanych substratów i produktów obróbki popiołu lotnego. Przeprowadzono analizę możliwości wydzielania koncentratów tytanu z popiołów lotnych powstających w procesie spalania w kotłach pyłowych z wybranych krajowych elektrowni. Stwierdzono zależność stężenia tytanu w otrzymanym koncentracie od temperatury prowadzenia procesu aktywacji oraz od rodzaju kwasu w procesie obróbki hydrometalurgicznej. Zawartość tytanu w otrzymanych koncentratach wynosiła od 39,3% do 60,8%, co odpowiada zawartości tego pierwiastka w eksploatowanych obecnie rudach tytanu.
EN
The purpose of the study was to highlight the possibility of using fly ash from coal combustion as a source of titanium concentrates. The research work carried out was aimed at determining the conditions for pretreatment of fly ash by alkaline thermal activation with sodium carbonate and their effect on the release of titanium compounds in the hydrometallurgical process. The process was carried out for mixtures of ash and sodium carbonate in a weight ratio of 1 to 1.1. The resulting mixtures were heated for 1 hour at temperatures of 973K, 1023K and 1083K. After cooling and grinding, the resulting reaction residue was washed with hydrochloric acid and nitric acid (V). The results of chemical analysis and scanning microscopic analysis, together with EDS and X-ray analysis, were used to determine the chemical and physical properties of the tested substrates and fly ash treatment products. An analysis of the possibility of separating titanium concentrates from fly ash generated during the combustion process in pulverized fuel boilers of selected domestic power plants was carried out. The dependence of titanium concentration in the obtained concentrate on the temperature of the activation process and on the type of acid in the hydrometallurgical treatment process was found. The content of titanium in the obtained concentrates ranged from 39.3% to 60.8%, which corresponds to the content of this element in currently exploited titanium ores.
Apatite-type structure is known for its flexibility towards accommodating numerous ions of different crystallographic affinities. Two samples of fluorellestadite from two pyrometamorphic rocks (slags) from burned waste heaps (BWH) from France (LdS) and Poland (RDT) were studied in terms of their trace element composition using Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Boron shows an evident, persistent enrichment in both the samples, with average/maximum levels of 497/1040 and 49/106 ppm, respectively. So is true for magnesium (884/16766 and 404/6251 ppm, i.e., respectively) and sodium (512/697 and 249/370 ppm, respectively). Germanium is clearly enriched in the first sample (29/40 ppm) and, to a lesser degree, in the second one (34 ppm on average). The LdS sample is also clearly enriched in Al (888/1238 ppm), K (385/697 ppm), Ti (515/943 ppm), V (172/347 ppm), and Cu (16/1369 ppm). The RDT sample is also rich in As (105/120 ppm) and Sr (1072/6592 ppm). An interesting feature of both samples concerns their REE pattern: Nd is the dominant element of the group, with the respective Nd/ΣLREE and Nd/(Ce+La) values of 0.43 and 0.90; and 0.37 and 0.66. In order from highest to lower average concentrations, aluminium, magnesium, titanium, boron, potassium, and germanium may be essential substituents in the BWH apatites.
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Additive manufacturing (AM) is one of the critical techniques of novel medical devices which is capable of processing complicated or customized structures to best match the human’s bones and tissues. AM allows for the fabrication of devices with optimal architectures, complicated morphologies, surface integrity, and regulated porosity and chemical composition. Various AM methods can now consistently fabricate dense products for a range of metallic, nonmetallic, composites, and nanocomposites. Different studies are available that describe the microstructure and various properties of 3D-printed biomedical alloys. However, there are limited research on the wear characteristics, corrosion resistance, and biocompatibility of 3D-printed technology-constructed biomedical alloys. In this article, AM metallic biomaterials such as stainless steel, magnesium, cobalt–chromium, and titanium are reviewed along with their alloys. The helicopter view of essential characteristics of these additively manufactured biomaterials is comprised. The review will have a significant impact on fabricating metallic surgical equipment and its sturdiness in the biomedical field.
Surface modification of the titanium and its alloys used in implantology with a long-pulse laser can change the surface topography, but it also leads to changes in the stress sign and magnitude in the resulting subsurface layer. The presented research was aimed at evaluating the state of stress after laser remelting with the Nd:YAG laser of pre-etched titanium alloys Ti6Al4V and Ti13Nb13Zr and pure titanium. The obtained surface layers were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), optical profilography, and nanoindentation studies. Based on the results obtained after the nanoindentation tests, the character of the stresses generated in the melted layers was calculated and determined. Laser processing resulted in surface layer thicknesses between 191-320 µm and surface roughness Ra between 2.89-5.40 µm. Laser processing caused increasing hardness, and its highest value was observed for the titanium alloy Ti13Nb13Zr - 5.18 GPa. The tensile stresses appeared following laser treatment and increased with elevating laser power up to the highest value for titanium.
This paper presents frustum cone drawpiece analysis made of titanium CP2 sheet by a single incremental sheet forming. Central composite design has been adopted to carry out an experiment containing 20 runs, then multi-criteria parameter optimization has been done. Optimal parameters have been validated and responses deviations do not exceed 4% compared to created models. For the drawpiece formed with optimal parameters, AGRUS optical measurement and X-ray tomography has been applied to check the obtained of the part wall thickness and general deviations compared to the CAD model. The wall angle discrepancy of the cone generatrix has also been analyzed. No gaps or ruptures have been confirmed by X-ray. The blank rolling direction has a significant effect on the drawpiece deviations. The measurement results showed deviations of the drawpiece wall angle +0.27°/- 0.06°, sheet thickness on the cone +0.012/-0.04 mm and +0.151/-0.096 mm from the reference CAD geometry.
PL
W pracy przedstawiono analizę wytłoczek w kształcie stożka ściętego wykonanego z blachy tytanowej CP2 metodą jednopunktowego przyrostowego kształtowania. Do przeprowadzenia eksperymentu obejmującego 20 przebiegów przyjęto centralny plan kompozycyjny, następnie dokonano wielokryterialnej optymalizacji parametrów. Dokonano walidacji optymalnych parametrów, a uzyskane wyniki nie przekraczają 4% w odniesieniu do stworzonych modeli. Dla wytłoczki uformowanej z optymalnymi parametrami zastosowano pomiar optyczny AGRUS oraz tomografię rentgenowską w celu sprawdzenia uzyskanej grubości ścianki wytłoczki i odchyłek w porównaniu z modelem CAD. Przeanalizowano również rozbieżność kątów ścian tworzących stożka. Za pomocą skanu rentgenowskiego potwierdzono brak szczelin i pęknięć wytłoczki. Kierunek walcowania półfabrykatu ma istotny wpływ na odchyłki. Wyniki pomiarów wykazały odchylenia kąta ścianki wytłoczki +0,27/-0,06°, grubości ścianki na stożku +0.012/-0.04 mm oraz +0.151/-0.096 mm od geometrii referencyjnej CAD.
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Tytan, a dokładniej jego stopy, okazał się doskonałym potencjalnym zamiennikiem stali. Ich łączenie jest możliwe z zastosowaniem wielu znanych technologii spawalniczych, ale w każdym przypadku wymaga szczególnego przygotowania procesu. W cz. I omówiono pokrótce podstawowe grupy stopów tytanu pod kątem specyfiki ich łączenia. Cz. II skupia się na metodach łączenia stopów tytanu, poczynając od najbardziej rozpowszechnionych, takich jak GTA, GMA, wiązką elektronów, a na rzadko stosowanych, takich jak lutozgrzewanie, łączenie wybuchowe i dyfuzyjne kończąc.
EN
Joining of titanium and its alloys is possible with the use of a wide range of welding technologies but in any separate case it needs special care and preparation of the process. The main groups of titanium alloys are briefly described regarding their specific joining requirements. Methods of Ti welding are presented, ranging from most widespread, like GTA, GMA and EBW, to the most unusual, like spot-brazing, detonation and diffusion joining. Guidelines and recommendations concerning the specific requirements of titanium welding with the chosen methods are also included.
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W artykule omówiono rodzaj i skład gazów używanych podczas spawania tytanu, cyrkonu i ich stopów, jak również opisano wpływ poszczególnych gazów na proces spawania i jakość złączy spawanych.
EN
The type and composition of gases used in the welding of titanium, zirconium and their alloys are discussed in the paper. The influence of shielding gases on the welding process and quality of welded joints is also described.
Recent developments of acid leaching of titanium concentrates and ores have produced renewed industrial and commercial interest. However, the leaching kinetics and mechanism of these concentrates and ores had received little attention. This work, therefore, addresses the leaching kinetics and mechanism of Ti from a rutile concentrate in sulfuric acid solution. The leaching reaction was controlled by diverse parameters like temperature, particle size, acid concentration, liquid/solid (L/S) ratio, and stirring speed. The leaching kinetics was investigated using the Shrinking Core Model in order to determine the optimum criteria which control the reaction. The kinetics analysis showed that the rate of dissolution of Ti increased by increasing reaction temperature, L/S ratio, and stirring speed, while it decreased upon increasing particle size. The kinetics analysis revealed that the dissolution reaction is controlled by the chemical reaction at the rutile particle surface. Applying the Arrhenius relation, the apparent energy of activation Ea for the leaching reaction was calculated to be 23.4kJ/mol. A semi-empirical overall rate equation was introduced to describe the combined effects of the process variables upon the rate of the dissolution reaction: [formula]
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W pracy przedstawiono analizę właściwości fizykochemicznych powłok na bazie winylotrójmetoksysilanu z dodatkiem surfaktantu – Tritonu X-100 – osadzonych na tytanie Grade 2 oraz stopie tytanu Ti6Al4V. Oceniono adhezję powłok do podłoża, grubość powłok, wpływ wytworzonych powłok na odporność korozyjną materiałów, a także wykonano analizę mikrostruktury i parametrów struktury geometrycznej powierzchni powłok przed badaniami korozyjnymi oraz po nich. Przyczepność powłok analizowano za pomocą taśmy ScotchTM. Odporność korozyjną analizowano za pomocą potencjodynamicznych krzywych polaryzacji w symulowanym płynie ustrojowym odwzorowującym warunki ludzkiego organizmu w celu oceny powłok pod kątem ich zastosowania w implantologii. Grubość powłok określono za pomocą mikroskopu cyfrowego KEYENCE VHX-7000 oraz miernika Testan DT-20 AN 120 157.
EN
This paper presents an analysis of the physicochemical properties of coatings based on vinyltrimethosysilane with the addition of Triton X-100 surfactant deposited on titanium Grade 2 and titanium alloy Ti6Al4V. The adhesion of coatings to the substrate, the thickness of the coatings, the influence of the produced coatings on the corrosion resistance of materials were assessed, and the microstructure and parameters of the geometric structure of the coatings surface were analyzed before and after corrosion tests. The adhesion of the coatings was analyzed with ScotchTM tape. Corrosion resistance was analyzed using potentiodynamic polarization curves in a simulated body fluid mapping the conditions of the human body in order to evaluate the coatings for their application in implantology. The thickness of the coatings was determined using the KEYENCE VHX-7000 digital microscope and the Testan DT-20 AN 120 157 meter.
This study aims to determine optimal forming parameters for Incremental Sheet Forming process Commercially Pure titanium Grade 2 sheets in terms of formability improvement, force reduction, and efficiency of forming. Based on the central composite design, data were collected during 20 runs and then variation analysis was performed. The experiments were performed on a 3 axis CNC milling machine equipped with a Kistler dynamometer plate. Subsequently, regression models have been developed to describe process responses by input factors. As crucial parameters, the relative velocity and step size of the tool that affect the forming force and the height of the fracture have been determined. Finally, the application of optimization algorithm has emerged optimal input factors in terms of selected multi-criteria goal. The results of this study suggest that there is a process window that allows the formation of 45° wall angle drawpieces of commercially pure titanium Grade 2.
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Łączenie tytanu i jego stopów jest możliwe z zastosowaniem wielu znanych technologii spawalniczych, ale w każdym przypadku wymaga szczególnego przygotowania procesu. Opisano pokrótce podstawowe grupy stopów tytanu pod kątem specyfiki ich łączenia. Przedstawiono metody łączenia stopów tytanu, poczynając od najbardziej rozpowszechnionych, takich jak GTA, GMA, wiązką elektronów, a na rzadko stosowanych, takich jak lutozgrzewanie, łączenie wybuchowe i dyfuzyjne kończąc. Podano wskazówki i zalecenia dotyczące specyfiki łączenia Ti wybranymi metodami.
EN
Joining of titanium and its alloys is possible with the use of a wide range of welding technologies but in any separate case it needs special care and preparation of the process. The main groups of titanium alloys are briefly described regarding their specific joining requirements. Methods of Ti welding are presented, ranging from most widespread, like GTA, GMA and EBW, to the most unusual, like spot-brazing, detonation and diffusion joining. Guidelines and recommendations concerning the specific requirements of titanium welding with the chosen methods are also included.
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An attempt has been made to study the influence of magnetic field on the micro hole machining of Ti-6Al-4V titanium alloy using electrochemical micromachining (ECMM) process. The presence of magneto hydro dynamics (MHD) is accomplished with the aid of external magnetic field (neodymium magnets) in order to improve the machining accuracy and the performance characteristics of ECMM. Close to ideal solution for magnetic and nonmagnetic field ECMM process, the parameters used are as follows: concentration electrolyte of 15 g/l; peak current of 1.35 A; pulse on time of 400 s; and duty factor of 0.5. An improvement of 11.91–52.43% and 23.51–129.68% in material removal rate (MRR) and 6.03–21.47% and 18.32–33.09% in overcut (OC) is observed in ECMM of titanium alloy under the influence of attraction and repulsion magnetic field, respectively, in correlation with nonmagnetic field ECMM process. A 55.34% surface roughness factor reduction is ascertained in the hole profile in magnetic field-ECMM in correlation with electrochemical machined titanium alloy under nonmagnetic field environment. No machining related stress is induced in the titanium alloy, even though environment of electrochemical machining process has been enhanced with the presence of magnetic field. A slight surge in the compressive residual factor, aids in surge of passivation potential of titanium alloy, resulting in higher resistance to outside environment.
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