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Wyszukujesz frazę "magnesium AZ91" wg kryterium: Temat


Tytuł:
Mechanical properties and structure evolution of the AZ91 magnesium alloy after hot rolling and annealing
Właściwości mechaniczne oraz struktura stopu AZ91 po walcowaniu na gorąco i wyżarzaniu
Autorzy:
Sułkowski, B.
Boczkal, G.
Powiązania:
https://bibliotekanauki.pl/articles/263807.pdf
Data publikacji:
2015
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
magnesium AZ91
hot rolling
texture
annealing
mechanical properties
stop magnezu AZ91
walcowanie na gorąco
tekstura
właściwości mechaniczne
Opis:
The AZ91 magnesium alloy was processed up to 87.5% of total thickness reduction in several thermodynamic routes, consisted of hot rolling and intermediate annealing. The hot-rolling process was performed at a high strain rate equal to 1.6 s−1 and at a temperature of 430°C. The intermediate annealing was performed at 430°C for 15 minutes after each route. It was found that, during hot rolling, the hardness of the material increased from 32 HV to 40 HV, and the structure investigations showed a huge amount of twins formed inside the grains (which were not observed after annealing). Tensile tests have shown strong anisotropy in mechanical properties of the “as-rolled” samples dependent onthe orientation between tension direction (TD) and rolling direction (RD). The samples with TD perpendicular to RD provedhigher ultimate tensile strength (UTS) and (on the other hand) worse plastic properties as compared to the samples with TD parallel to RD. The annealing has an effect on the reduction of mechanical properties anisotropy. X-ray investigations have shown texture changes from the basal type with the additional (0001) <1120> component for “as-rolled” samples to the texture with the main (0001) <1010> component for annealed samples. The texture changes had a great impact on the anisotropy of mechanical properties of the investigated AZ91 magnesium alloy.
Stop magnezu AZ91 był walcowany na gorąco ze zgniotem 87.5% w kilku operacjach walcowania-wyżarzania. Walcowanie na gorąco było przeprowadzone w temperaturze 430°C z prędkością odkształcenia 1.6 s−1. Wyżarzanie międzyoperacyjne przeprowadzano w temperaturze 430°C przez 15 minut. Po walcowaniu twardość stopu AZ91 wzrosła od wartości 32 HV do wartości 40 HV, a obserwacje struktury wykazały obecność wewnątrz ziaren dużej liczby bliźniaków. Po przeprowadzeniu wyżarzania (15 minut, 430°C) nie zaobserwowano obecności bliźniaków. Wyniki badań z próby rozciągania wykazały silną anizotropię własności mechanicznych w zależności od ułożenia kierunku rozciągania (KR) próbek wtórnych względem kierunku walcowania (KW).Przeprowadzone wyżarzanie spowodowało zmniejszenie anizotropii właściwości mechanicznych w badanym materiale. Przeprowadzone badania rentgenowskie wykazały zmiany w teksturze z typu bazalnego z dodatkowym komponentem (0001) <1120>dla próbek po walcowaniu na typ tekstury z głównym komponentem (0001) <1010> dla próbek wyżarzanych. Zmiany tekstury miały silny wpływ na zaobserwowaną anizotropię właściwości mechanicznych badanego stopu AZ91 po walcowaniu na gorąco i wyżarzaniu.
Źródło:
Metallurgy and Foundry Engineering; 2015, 41, 3; 143-151
1230-2325
2300-8377
Pojawia się w:
Metallurgy and Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kształtowanie odlewniczego stopu magnezu AZ91 na tle prób wyciskania współbieżnego
Forming of casting magnesium alloy AZ91 against direct extrusion
Autorzy:
Ziółkiewicz, S.
Jankowski, Ł.
Gronowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/211556.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Obróbki Plastycznej
Tematy:
stop magnezu AZ91
wyciskanie współbieżne
plastyczność
magnesium alloy AZ91
direct extrusion
plasticity
Opis:
Stopy magnezu stają się coraz popularniejszym materiałem konstrukcyjnym wykorzystywanym w gospodarce. Przyczyną tego jest między innymi korzystny stosunek własności wytrzymałościowych do masy, wykorzystywany w przemyśle motoryzacyjnym oraz zdolności stopów magnezu do tłumienia zakłóceń o źródle elektromagnetycznym, co wykorzystywane jest w zaawansowanych technologiach teleinformatycznych. Najczęściej wykorzystuje się stopy odlewnicze z grupy AZ (Magnez-Aluminium-Cynk) i AM (Magnez-Aluminium-Mangan). Poszukuje się jednak nowych metod wytwarzania, które pozwalają na podniesienie własności użytkowych wyrobów. Taką technologią jest obróbka plastyczna, która poprzez zmianę formy wpływa znacząco na zmianę struktury, a tym samym na własności kształtowanych metali. W artykule podjęto problem przeróbki plastycznej trudno odkształcalnego stopu magnezu z grupy AZ. Celem prac było przeprowadzenie badań technologicznych możliwości odkształcalności stopu AZ91. Badania prowadzono na surowych wlewkach w procesie wyciskania współbieżnego prętów, w zakresie temperatur 280-360˚C, na stanowisku prasy hydraulicznej wyposażonej w specjalny przyrząd z układem grzewczym narzędzi. W artykule przedstawiono napotkane w trakcie realizacji badań wady w wytwarzanych prętach oraz metody poszukiwania rozwiązań optymalnego procesu technologicznego. W wyniku realizacji badań stwierdzono, że istotnym elementem procesu technologicznego jest stan wyjściowy wsadu. Wsad przed procesem wyciskania musi zostać poddany przesycaniu w celu rozpuszczenia się kruchej fazy γ-Mg17Al12. Stwierdzono również, że istnieje możliwość wyciskania współbieżnego do postaci prętów w bardzo wąskim zakresie temperatur 290±10˚C.
Magnesium alloys are more and more popular constructional materials used in the economy. Among other things, reasons for that include an advantageous relation of mechanical properties to the mass, used in the automotive industry, and the abilities of magnesium alloys to suppress electromagnetic noises what is used in advanced tele-information technologies. The casting alloys included in the group AZ (Magnesium-Aluminium-Zinc) and AM (Magnesium-Aluminium-Manganese) are used most often. However, new manufacturing methods that allow to improve operational properties of products are searched for. Such a technology is a plastic forming that through a change of the form affects significantly the change of structure, therefore, the properties of formed metals. The article brings up a problem of plastic working of hard deformable magnesium alloy included in the group AZ. The purpose of theses researches was to perform technological tests of deformability capabilities of alloy AZ91. The tests were performed using raw ingots in the process of direct extrusion of the bars, within the range of temperatures of 280-360˚C, on a station of hydraulic press equipped with a special instrument with heating tool system. The article presents defects in manufactured bars, met during the realization of researches, and methods of searching for solutions of optimal technological process. As a result of the realization of researches, it is stated that an essential element of technological process is an initial state of charge. Prior to the extrusion process the charge must be subjected to solution heat treatment in order to dissolve a brittle phase γ-Mg17Al12. It is also stated that there is a possibility of direct extrusion to the form of bars within a very narrow range of temperatures of 290±10˚C.
Źródło:
Obróbka Plastyczna Metali; 2013, 24, 2; 109-117
0867-2628
Pojawia się w:
Obróbka Plastyczna Metali
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Benefit Effect of Low Addition Yttrium on the Phase αMg and eutectic αMg+γ(Mg17Al12) in AZ91 Alloy
Autorzy:
Mikusek, D.
Rapiejko, C.
Andrzejczak, A.
Pacyniak, T.
Powiązania:
https://bibliotekanauki.pl/articles/2049625.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnesium alloy AZ91
yttrium
grain refining
solidification process
investment casting
Opis:
This paper presents results of a study of the effect of inoculation of yttrium on the microstructure of AZ91 alloy. The concentration of the inoculant was increased in samples in the range from 0.1% up to 0.6%. The influence of Y on the thermal effects resulting from the phase transformations occurring during the crystallisation at different inoculant concentrations were examined with the use of Derivative and Thermal Analysis (DTA). The microstructures of the samples were examined with the use of an optical microscope; and an image analysis with a statistical analysis were also carried out. Those analyses aimed at examining oh the effect of inoculation of the Y on the differences between the grain diameters of phase αMg and eutectic αMg+γ(Mg17Al12) in the prepared examined material as well as the average size of each type of grain by way of measuring their perimeters.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 1; 57-63
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena odkształcenia granicznego stopu magnezu AZ91
Assessment of limit deformation of AZ91 magnesium alloy
Autorzy:
Ziółkiewicz, S.
Gąsiorkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/212029.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Obróbki Plastycznej
Tematy:
stop magnezu AZ91
metoda KOBO
obróbka plastyczna
magnesium alloy AZ91
KOBO method
plastic working
Opis:
W pracy przedstawiono wyniki badań wpływu procesu wyciskania ze zmienną drogą odkształcenia i procesu wyciskania współbieżnego na właściwości plastyczne stopu magnezu AZ91. Wyniki wskazują, że przetworzenie wlewka metodą KOBO w wąskim zakresie temperatury, może doprowadzić do cech nadplastycznych badanego stopu. W artykule przedstawiono wyniki badań prowadzonych w Instytucie Obróbki Plastycznej.
This paper presents the results of research influence of extrusion on variable way of deformation AZ91 magnesium alloy. The results indicate that the corresponding processing of the ingot by KOBO extrusion method can lead investigated alloy to superplastic flow. This paper presents the results of a preliminary study.
Źródło:
Obróbka Plastyczna Metali; 2013, 24, 2; 99-107
0867-2628
Pojawia się w:
Obróbka Plastyczna Metali
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Output Responses during EDM of AZ91 Magnesium Alloy using Grey Relational Analysis and TOPSIS
Autorzy:
Tajdeen, A.
Megalingam, A.
Powiązania:
https://bibliotekanauki.pl/articles/2049133.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AZ91 magnesium alloy
EDM
TOPSiS
GRA
ANOVA
Opis:
Unconventional machining of magnesium alloys through die sinking and Wire electrical discharge Machining (WEDM) processes are preferred over conventional machining processes to overcome the rapid loss in strength and affinity that occurs with tool materials at high temperatures. in the present study, AZ91 magnesium alloy is machined in EDM using a prepared alloy tool (copper alloyed with titanium diboride). Based on Taguchi’s l27 orthogonal array, a total of 27 experiments have been conducted by varying the process parameters such as pulse on time (Ton), gap voltage (Vg) and current (Ip) with three different levels. Techniques for Order Preference by Similarity to ideal Solution (TOPSIS) and Grey Relational Analysis (GRA) have been applied to optimize the response parameters of EDM to obtain maximum Material Removal Rate (MRR) and minimum Tool Wear Rate (TWR) and Surface Roughness (SR). Analysis of variance (ANOVA) is carried out based on F-test at a confidence interval of 95% to confirm the significant influence of individual parameters. From the above two optimization techniques, the obtained optimal values are current 15 A, gap voltage 55 V, pulse on time 30 μs and an error of less than 5% is observed from the confirmation experiments. Scanning Electron Microscope (SEM) images revealed that there is no formation of cracks but micro pits and holes are observed.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 4; 1105-1113
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Tribological and Mechanical Properties of Biodegradable AZ91 Alloy Produced by Cold Chamber High Pressure Casting Method
Autorzy:
Urtekin, Levent
Arslan, Recep
Bozkurt, Fatih
Er, Ümit
Powiązania:
https://bibliotekanauki.pl/articles/2049430.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
die casting
AZ91 magnesium alloy
cold chamber high pressure casting method
mechanical properties of AZ91 magnesium alloy
wear of AZ91 alloy
tribological properties of AZ91 alloy
Opis:
In this study, AZ91 Magnesium alloy is produced by cold chamber high pressure die casting (HPDC) method. Different combinations of the cold chamber HPDC process parameters were selected as; in-mold pressure values of 1000 bar and 1200 bar, the gate speed of 30 m/s and 45 m/s, the casting temperatures of 640°C and 680°C. In addition, the test samples were produced by conventional casting method. Tensile test, hardness test, dry sliding wear test and microstructure analysis of samples were performed. The mechanical properties of the samples produced by the cold chamber HPDC and the conventional casting method were compared. Using these parameters; the casting temperature 680°C, in-mold pressure 1000 bar and the gate speed 30 m/s, the highest tensile strength and the hardness value were obtained. Since the cooling rate in the conventional casting method is slower than that of the cold chamber HPDC method, high mechanical properties are obtained by the formation of a fine-grained structure in the cold chamber HPDC method. In dry sliding wear tests, it was observed that there was a decrease in friction coefficient and less material loss with the increase of hardness values of the sample produced by the cold chamber HPDC method.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 1; 205-216
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface modification of AZ91 magnesium alloy using GTAW technology
Autorzy:
Iwaszko, J.
Strzelecka, M.
Kudła, K.
Powiązania:
https://bibliotekanauki.pl/articles/201803.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
remelting treatment
GTAW technology
AZ91 magnesium alloy
przetapianie
technologia GTAW
stop magnezu AZ91
Opis:
In this study, surface remelting treatment of the AZ91 magnesium alloy by means of welding using a non-consumable electrode in an inert gas shield was carried out. Three variants of surface treatment were used, i.e. the single torch variant with a single heat source without cooling down the samples, the single torch variant with a single heat source and a cooling system with liquid nitrogen, and the double welding torch variant with a double heat source in the torches operating in a tandem configuration. Experimental verification of the applied apparatus solutions was based on both macro- and microstructural assessment of the obtained effects. Comparative analysis of the variants used and the obtained microstructural results allowed the authors to indicate the deficiencies and limitations of particular solutions and to single out the best solution that would be useful for modifying the surface layers of magnesium alloys, as well as other materials having a strong oxygen affinity.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2017, 65, 6; 917-926
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Temperature Mechanical Properties of AZ91 Magnesium Alloy Weld Joint
Autorzy:
Stopyra, M.
Adamiec, J.
Powiązania:
https://bibliotekanauki.pl/articles/382357.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mechanical properties
AZ91 magnesium alloy
welding method
właściwości mechaniczne
stop magnezu AZ91
metoda spawania
Opis:
Magnesium alloys are widely applied in aircraft and automotive industry, due to their low density and high specific strength. Welding methods can be used to join Mg alloy elements and to repair or regenerate defective or worn-out castings. Therefore the influence of weld joint’s microstructure on mechanical properties needs to be studied. In present paper high temperature mechanical properties of AZ91 Mg alloy weld joint was investigated. Tensile tests were conducted in temperature range between 20 and 200°C. Ultimate tensile strength decreased as the temperature increased from 50°C. At temperature up to 150°C rapture occurred in the base metal, at 200°C rupture location switched to the weld fusion zone. Based on metallographic and fractographic observation, the fracture mechanism was described. Macro crack formed from the merger of micro cracks occurring at massive β phase precipitates.
Źródło:
Archives of Foundry Engineering; 2013, 13, 1 spec.; 181-184
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of process temperature on AZ91 matrix microstructure of composites with aluminosilicate glass cenospheres
Autorzy:
Kamieniak, J.
Żydek, A.
Braszczyńska-Malik, K. N.
Powiązania:
https://bibliotekanauki.pl/articles/380096.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AZ91 magnesium alloy
metal matrix composite
glass cenosphere
stop magnezu AZ91
kompozyt metalowy
cenosfera
Opis:
AZ91 magnesium alloy matrix composites with aluminosilicate glass cenospheres were fabricated successfully by the pressure infiltration method. Different parameters of the fabrication process, such as temperature of the mould and temperature of cenospheres were used. Influence of the temperature variation of particular parameters on the microstructure has been investigated. The microstructure of AZ91 magnesium alloy and fabricated composites have been investigated by light microscopy (LM) and scanning electron microscopy (SEM). The results revealed that AZ91 magnesium alloy consists of α-Mg matrix and eutectic α-Mg17Al12 and a small amount of discontinuous precipitates of γ phase. The microstructure of matrix AZ91 in fabricated composites is characterized also by the presence of α-Mg matrix and eutectic α-Mg17Al12. However, in the composite fabricated by using the mould heated to 500 °C more discontinuous precipitates of γ phase were observed.
Źródło:
Archives of Foundry Engineering; 2011, 11, 3 spec.; 107-110
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aluminosilcate glass cenospheres as a component of cast magnesium matrix composites
Autorzy:
Kamieniak, J.
Żydek, A.
Braszczyńska-Malik, K. N.
Powiązania:
https://bibliotekanauki.pl/articles/382002.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AZ91 magnesium alloy
aluminosilicate cenospheres
metal matrix composite
stop magnezu AZ91
mikrosfera glinokrzemianowa
kompozyt metalowy
Opis:
The main characteristic of aluminosilicate glass cenospheres and their possible use as a component of magnesium matrix composites were presented. The results revealed that particular parts of cenospheres differ insignificantly from each other and it depends on which power plant cenospheres come from. The characteristic of cenospheres concerned their structure and phase composition and dimensions such as: wall thickness and size of pores occurring in walls, depending on cenospheres origin. Thickness of cenospheres walls and pore size were measured by using ImageJ computer software. The structure of aluminosilicate glass cenospheres and their phase composition have been investigated by scanning electron microscopy and X-ray diffraction (XRD). The possibility of cenospheres utilization in the fabrication of magnesium matrix composites was presented on the example of AZ91 magnesium alloy composite with fly ash cenospheres. Composite was fabricated by pressure infiltration method.
Źródło:
Archives of Foundry Engineering; 2011, 11, 2 spec.; 109-112
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena możliwości kształtowania właściwości mechanicznych odlewniczego stopu magnezu AZ91 przez zastosowanie odpowiedniej obróbki cieplnej
An assessment of the possibilities to shape the mechanical properties of cast AZ91 magnesium alloy through application of proper heat treatment
Autorzy:
Reguła, T.
Bronicki, M.
Lech-Grega, M.
Czekaj, E.
Powiązania:
https://bibliotekanauki.pl/articles/391628.pdf
Data publikacji:
2008
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
stop magnezu AZ91
odlewanie
obróbka cieplna
właściwości mechaniczne
AZ91 magnesium alloy
casting
heat treatment
mechanical properties
Opis:
Celem publikacji jest ocena wpływu różnych sposobów klasycznej obróbki cieplnej na zmiany właściwości mechanicznych - w temperaturze pokojowej - stopu magnezowego typu AZ91, w odniesieniu do analogicznych charakterystyk dla stanu wyjściowego (lanego). Materiał badawczy odlewano grawitacyjnie do form piaskowych oraz kokil. Odpowiednio przygotowane mechanicznie próbki poddano obróbce cieplnej, podczas której doprowadzone zostały ze stanu wyjściowego (F - as-fabricated) do stanów: T4, T5 oraz T6. Badanie właściwości mechanicznych obejmowało wyznaczenie Rm, Rp02 i A5 w statycznych próbach rozciągania oraz pomiary twardości (HB) metodą Brinella. Wyniki badań wskazują, iż właściwości mechaniczne odlewniczego stopu AZ91 można w istotny sposób kształtować, poprzez zastosowanie odpowiedniej obróbki cieplnej.
The aim of this publication is to assess the effect of different types of the standard heat treatment on changes in mechanical properties at room temperature of magnesium alloy from AZ91 family referred to the same properties in as-fabricated state. The investigated alloy was gravity cast into sand and metal moulds. The mechanically prepared specimens were subjected to a heat treatment during which they were transformed from the as-fabricated state to conditions: T4, T5 and T6. Testing of mechanical properties included determination of Rm, Rp02 and A5 during static tensile test and Brinell hardness measurements (HB). The results of the investigations indicate that the mechanical properties of cast AZ91 alloy can be successfully shaped through the application of proper heat treatment.
Źródło:
Prace Instytutu Odlewnictwa; 2008, 48, 1; 41-47
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations on the Microstructure and Corrosion Performance of Different WC-Based Cermet Coatings Deposited by High Velocity Oxy Fuel Process onto Magnesium Alloy Substrate
Autorzy:
Jonda, Ewa
Łatka, Leszek
Maciej, Artur
Khozhanov, Aleksandr
Powiązania:
https://bibliotekanauki.pl/articles/2201928.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
AZ91 magnesium alloy
HVOF
thermal spraying
metal matrix composite coatings
microstructure
electrochemical corrosion
Opis:
In the field of surface engineering, thermal spraying is very wide adopted in many branches of the industry. The main reasons of such situation are its flexibility as well as cost effectiveness. Among others, High Velocity Oxy Fuel (HVOF) technique is dedicated for spraying hardmetal and cermet coatings, especially for wear- and corrosion resistance. Such type of coating could be a promising candidate as protective layer for magnesium alloys elements. These materials need a strong improvement in the corrosion protection as well as on the field of wear resistance in order to be widely used in the industry. In this work, different WC-based coatings, namely: (i) WC-Co, (ii) WC-Co-Cr and (iii) WC-Cr3C2-Ni manufactured by HVOF spraying, were investigated. The form of all feedstock materials was agglomerated and sintered powder. All coatings were sprayed with the same technological parameters, especially spray distance which was equal to 400 mm on the AZ91 magnesium alloy substrate. The main aim of the studies was to investigate the influence of the powder material on the corrosion resistance of obtained coatings. The manufactured coatings were examined in terms of its microstructure, using scanning electron microscope (SEM) and corrosion performance, which was assessed in the electrochemical corrosion investigations in 3.5% NaCl solution by Tafel method. The study showed that the corrosion resistance increasing in such order: AZ91 < WC-Cr3C2-Ni < WC-Co < WC-Co-Cr. It should be stressed that WC-Cr3C2-Ni coating exhibits very low corrosion performance, which could be effected by relatively high porosity (c.a. 3 vol.%) and because of that the more complex composition promotes creation of many corrosion cells.
Źródło:
Advances in Science and Technology. Research Journal; 2023, 17, 2; 25--35
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Positron annihilation lifetime spectroscopy study of roller burnished magnesium alloy
Autorzy:
Zaleski, R.
Zaleski, K.
Gorgol, M.
Powiązania:
https://bibliotekanauki.pl/articles/146650.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
AZ91HP magnesium alloy
defects
positron lifetime annihilation spectroscopy (PALS)
roller burnishing
Vickers hardness test
Opis:
The effect of roller burnishing on Vickers’ hardness and positron lifetimes in the AZ91HP magnesium alloy was studied. The microhardness increases with an increase in the burnishing force and with a decrease in the feed. The comparison of various methods of analysis of positron annihilation lifetime (PAL) spectra allowed identification of two components, which are related to solute-vacancy complexes and vacancy clusters, respectively. It was found that the increase in microhardness was related to the increase in the concentration of vacancy clusters.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 789-794
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Artificial neural networks in mechanical surface enhancement technique for the prediction of surface roughness and microhardness of magnesium alloy
Autorzy:
Cagan, S. C.
Maci, M.
Buldum, M. M.
Maci, C.
Powiązania:
https://bibliotekanauki.pl/articles/201157.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
artificial neural network
prediction
ball burnishing
magnesium alloys
AZ91D
Opis:
The artificial neural network method (ANN) is widely used in both modeling and optimization of manufacturing processes. Determination of optimum processing parameters plays a key role as far as both cost and time are concerned within the manufacturing sector. The burnishing process is simple, easy and cost-effective, and thus it is more common to replace other surface finishing processes in the manufacturing sector. This study investigates the effect of burnishing parameters such as the number of passes, burnishing force, burnishing speed and feed rate on the surface roughness and microhardness of an AZ91D magnesium alloy using different artificial neural network models (i.e. the function fitting neural network (FITNET), generalized regression neural network (GRNN), cascade-forward neural network (CFNN) and feed-forward neural network (FFNN). A total of 1440 different estimates were made by means of ANN methods using different parameters. The best average performance results for surface roughness and microhardness are obtained by the FITNET model (i.e. mean square error (MSE): 0.00060608, mean absolute error (MAE): 0.01556013, multiple correlation coefficient (R): 0.99944545), using the Bayesian regularization process (trainbr)). The FITNET model is followed by the FFNN (i.e. MAE: 0.01707086, MSE: 0.00072907, R: 0.99932069) and CFNN (i.e. MAE: 0.01759166, MSE: 0.00080154, R: 0.99924845) models with very small differences, respectively. The GRNN model has noted worse estimation results (i.e. MSE: 0.00198232, MAE: 0.02973829, R: 0.99900783) as compared with the other models. As a result, MSE, MAE and R values show that it is possible to predict the surface roughness and microhardness results of the burnishing process with high accuracy using ANN models.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 4; 729-739
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Crystallization of AZ91 Alloy by Thermal and Derivative Analysis Method Intensively Cooled in Ceramic Shell
Autorzy:
Rapiejko, C.
Pisarek, B.
Czekaj, E.
Pacyniak, T.
Powiązania:
https://bibliotekanauki.pl/articles/380100.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
innovative casting materials
innovative casting technology
magnesium alloys
TDA method
hardness
crystallization
alloy AZ91
innowacyjne materiały odlewnicze
innowacyjna technologia odlewania
metoda ATD
krystalizacja
stop AZ91
Opis:
The work presents the test result of the influence of cooling rate on the microstructure of AZ91 alloy, Vickers micro-hardness and Brinell hardness. Studies cooling and crystallization of AZ91 alloy was cast into the ceramic shells pre-heated to 180°C and then air-cooled at ambient temperature or intensively super cooled in the liquid coolant. The TDA method was applied to record and characterize the thermal effect resulting from the phase transformations occurring during the crystallization of AZ91 alloy. The kinetics and dynamics of the thermal processes of crystallization of AZ91 alloy in the ceramic shells were determined. Metallographic tests were performed with the use of an optical microscope. A comparison of these test results with the thermal effect recorded by way of the TDA method was made. Influence of cooling rate of AZ91 on HV0, 01 micro-hardness and Brinell hardness alloy was examined.
Źródło:
Archives of Foundry Engineering; 2014, 14, 1; 97-102
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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