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Tytuł:
„Słownik polskiej terminologii prawosławnej” – struktura artykułu hasłowego
Autorzy:
Czarnecka, Katarzyna
Ławreszuk, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2057269.pdf
Data publikacji:
2018-12-21
Wydawca:
Uniwersytet w Białymstoku. Wydawnictwo Uniwersytetu w Białymstoku
Tematy:
dictionary
microstructure
entry
terminology
Orthodoxy
religious language
słownik
mikrostruktura
artykuł hasłowy
terminologia
prawosławie
język religijny
Opis:
Celem artykułu jest prezentacja projektu mikrostruktury „Słownika polskiej terminologii prawosławnej”, realizowanego w ramach grantu Narodowego Programu Rozwoju Humanistyki (Moduł; dziedzictwo narodowe, I/2016). Autorzy przedstawiają schemat artykułu, obejmujący 10 segmentów: 1. Wyraz hasłowy, 2. Wymowa, 3. Warianty wyrazu hasłowego, 4. Odpowiedniki obcojęzyczne, 5. Kwalifikator, 6. Definicja, 7. Skrót, 8. Połączenia wyrazowe, 9. Synonimy, 10. Uwagi poprawnościowe. Następnie omawia się każdy z bloków, przedstawiając jego koncepcję, wybrane uzasadnienia, praktyczne rozwiązania i szczegółowe zasady zapisu danych.
The article presents the design of the microstructure of the “Dictionary of Polish Orthodox Terminology”, an implementation of the grant of the National Program for the Development of Humanities (Module: The National Heritage, I / 2016). The authors present a design of an entry structure consisting of ten segments: 1. A headword; 2. Pronunciation; 3; Headword variants; 4. Equivalents of the headword in other languages; 5. The qualifier; 6. Definition; 7. Abbreviation; 8. Collocations; 9. Synonyms; 10. Notes on usage correctness. Then, each segment is discussed, and the concept underlying it is presented, as well as arguments for particular decisions, practical solutions and detailed rules for data recording.
Źródło:
ELPIS; 2018, 20; 221-230
1508-7719
Pojawia się w:
ELPIS
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Bivariate Copula-based Model for a Mixed Binary-Continuous Distribution: A Time Series Approach
Autorzy:
Bień-Barkowska, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/483353.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
copula function
mixed binary-continuous distribution
ACD models
market microstructure
Opis:
In this paper we present a copula-based model for a binary and a continuous variable in a time series setup. Within this modeling framework both marginals can be equipped with their own dynamics whereas the contemporaneous dependence between both processes can be flexibly captured via a copula function. We propose a method for testing the goodness-offit of such a time series model using probability integral transforms (PIT). This verification procedure allows not only a verification of the goodness-offit of the estimated marginal distribution for a continuous variable but also the conditional distribution of a continuous variable given the outcome of its binary counterpart (i.e. the adequacy of the copula choice). We test the model on an empirical example: investigating the relationship between trading volume and the indicators of arbitrarily ’large’ price movements on the interbank EUR/PLN spot market.
Źródło:
Central European Journal of Economic Modelling and Econometrics; 2012, 4, 2; 117-142
2080-0886
2080-119X
Pojawia się w:
Central European Journal of Economic Modelling and Econometrics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comparative Study of Residual Stress and Mechanical Properties for FSW and TIG Weld on Structural Steel
Autorzy:
Chaurasia, P. K.
Pandey, C.
Giri, A.
Saini, N.
Mahapatra, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/354742.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FSW
TIG
residual stress
microstructure
hardness
Opis:
Mechanical properties and residual stresses of friction stir welded and autogenous tungsten inert gas welded structural steel butt welds have been studied. Friction stir welding (FSW) of structural steel butt joints has been carried out by in-house prepared tungsten carbide tool with 20 mm/min welding speed and 931 rpm tool rotation. Tungsten inert gas (TIG) welding of the butt joints was carried out with welding current, arc voltage and the welding speed of 140 amp, 12 V and 90 mm/min respectively. Residual stress measurement in the butt welds has been carried out in weld fusion zone and heat affected zone (HAZ) by using blind hole drilling method. The magnitude of longitudinal residual stress along the weld line of TIG welded joints were observed to be higher than friction stir welded joint. In both TIG and FSW joints, the nature of longitudinal stress in the base metal was observed to be compressive whereas in HAZ was observed to be tensile. It can be stated that butt welds produced with FSW process had residual stress much lower than the autogenous TIG welds.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 1019-1029
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparative study of two nuclear steel grades welded joints
Autorzy:
Sirohi, Sachin
Pandey, Chandan
Goyal, Amit
Powiązania:
https://bibliotekanauki.pl/articles/353262.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microstructure
GTAW
P91 steel
P92 steel
δ ferrite
Opis:
In present work, two nuclear grade steel (P91, P92) are joined using the arc welding process. The welded joints were subjected to the heat treatment in order to restore the mechanical properties and overcome the heterogeneity across the joints. The weldments were studied for microstructure evolution and mechanical behavior under different condition of heat treatment. The variation in mechanical behavior obtained for the welded joints were tried to relate the microstructural evolution. After the normalizing based heat treatment, homogeneity with negligible δ ferrite across the welded joints was observed.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 2; 583-593
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comparative Study on Ex-Situ & In-Situ Formed Metal Matrix Composites
Autorzy:
Gobalakrishnan, B.
Rajaravi, C.
Udhayakumar, Gobikrishnan
Lakshminarayanan, P. R.
Powiązania:
https://bibliotekanauki.pl/articles/2203734.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
MMCs
Al-SiC
Al-TiB2
extrusion
heat treatment
mechanical properties
microstructure
Opis:
An attempt has been made to synthesize the aluminium based ex-situ (Al-SiC) and in-situ (Al-TiB2) formed metal matrix composites with varying weight percentage of reinforcement contents such as 4wt.%, 6wt.% and 8wt.%. Synthesized composites were subjected to a cold extrusion process followed by heat treatment according to the ASTM B 918-01 standards. The mechanical properties of in-situ composites were evaluated as per the ASTM guidelines and compared with ex-situ formed composites and base metal properties. Superior properties were noticed in the in-situ formed composites and the mechanical properties such as yield strength, Ultimate tensile strength (UTS) and Hardness for both ex-situ and in-situ composites were found to increase with increasing the reinforcement addition. Cold extruded Al-8 wt.% SiC composite properties such as hardness, yield strength and UTS are 87 RB, 152 MPa, 216 MPa respectively. Whereas, for Al-8 wt.% TiB2 composite, the corresponding properties are 94 RB, 192 MPa, 293 MPa. The morphology of the composites is analysed by Optical and Scanning Electron Microscopic (SEM) whereas presence of reinforcement particles such SiC and TiB2 along with intermetallic phases Mg2Si and Al5FeSi are confirmed by EDX, XRD and Element Mapping analyses.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 1; 171--185
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparison of the oxygen, nitrogen and hydrogen content in ductile iron castings and their effect on microstructure and mechanical properties
Autorzy:
Kamińska, J.
Basińska, E.
Stefański, Z.
Angrecki, M.
Powiązania:
https://bibliotekanauki.pl/articles/391558.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
ductile iron
oxygen/nitrogen/hydrogen content
methods of spheroidizing treatment
reaction chamber (reactor)
Opis:
Two different spheroidization methods were compared in terms of the effect they may have on gas content (oxygen, nitrogen and hydrogen) in ductile iron castings and process efficiency. Two methods of cast iron treatment were investigated, i.e. spheroidization in the foundry mould using a reaction chamber (reactor) developed by the Foundry Research Institute and, as a reference, the method currently used by foundry shops, i.e. spheroidization in the foundry ladle. The effect of spheroidization process was evaluated on test castings. The results of metallographic examinations and mechanical tests as well as the results of measurements of the oxygen, nitrogen and hydrogen content in cast iron after spheroidizing treatment were presented.
Źródło:
Prace Instytutu Odlewnictwa; 2017, 57, 4; 357-361
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comparison of Tribological Performances of Al2O3 and Al2O3 + 40 WT. % Tio2 Coatings Manufactured by Atmospheric Plasma Spraying
Porównanie właściwości tribologicznych powłok Al2o3 oraz Al2o3 + 40% wag . Tio2 wytworzonych metodą atmosferycznego natryskiwania plazmowego
Autorzy:
Niemiec, Aneta
Michalak, Monika
Łatka, Leszek
Sokołowski, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/188153.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
plasma spraying
coating
microstructure
wear resistance
microhardness
natryskiwanie plazmowe
powłoka
mikrostruktura
odporność na zużycie ścierne
mikrotwardość
Opis:
In this paper, the results of tribological, microscopic and mechanical research of Al2O3 and Al2O3 + 40 wt.% TiO2 coatings manufactured by atmospheric plasma spraying (APS) were presented. The feedstock materials were Al2O3 (Metco 6103, Oerlikon Metco) and Al2O3 + 40 wt.% TiO2 (Metco 131VF, Oerlikon Metco) powders with the average grain size of 30 μm. The stainless steel (X5CrNi18-10) coupons had a diameter equal to 25 mm and 2 mm of thickness. The morphology and microstructure of obtained coatings were tested by scanning electron microscope (SEM). Then adhesion tests and tribological examinations by ball-on-disc (BoD) mode in technical dry friction conditions were carried out. During BoD testing, the load of 5 N was used. It was concluded that the Al2O3 coating was characterized by higher wear resistance and microhardness, but, at the same time, it was of lower fracture toughness than the Al2O3 + 40 wt.% TiO2 coating.
W artykule przedstawiono wyniki badań tribologicznych, mikroskopowych oraz mechanicznych powłok Al2O3 oraz Al2O3 + 40% wag. TiO2, natryskanych metodą atmosferycznego natryskiwania cieplnego (APS). Materiałem na powłoki były proszki Al2O3 (Metco 6103, Oerlikon Metco) oraz Al2O3 + 40% wag. TiO2 (Metco 131VF, Oerlikon Metco) o średniej wielkości cząstek wynoszącej 30 μm. Jako podłoże zostały użyte krążki ze stali austenitycznej X5CrNi18-10 o średnicy 25 mm i grubości 2 mm. Morfologię i mikrostrukturę uzyskanych powłok oceniono przy pomocy skaningowego mikroskopu elektronowego (SEM). Po określeniu przyczepności powłok wykonano badania tribologiczne w styku kula–tarcza w warunkach tarcia technicznie suchego. Zastosowano obciążenie 5 N. Na podstawie przeprowadzonych badań stwierdzono, że powłoki na bazie Al2O3 wykazują większą odporność na zużycie ścierne oraz wyższą mikrotwardość, ale jednocześnie mniejszą odporność na kruche pękanie (KIC) w porównaniu z powłokami na bazie Al2O3 + 40% wag. TiO2.
Źródło:
Tribologia; 2019, 286, 4; 63-71
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A contibutionto evaluation of effective moduli of trabecular bone with rod-like microstructure
Autorzy:
Gałka, A.
Telega, J.J.
Tokarzewski, S.
Powiązania:
https://bibliotekanauki.pl/articles/280148.pdf
Data publikacji:
1999
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
trabecular bone
effective elastic moduli
homogenization
Opis:
The homogenization theory has been applied to evaluation of effective moduli of a network of interconnected elastic rods modelling human cancellous bone. Numerical computations of the Young modulus, Poisson ratio and shear modulus have been carried out. The obtained results compare fevourably with available experimental data.
Teorię homogenizacji zastosowano do wyznaczania efektywnych własności mechanicznych dla regularnej sieci elastycznych prętów modelujących kość gąbczastą. Wyznaczono numerycznie efektywne stałe techniczne: moduł Younga, współczynnik Poissona i moduł ścinania. Wyniki porównano z wynikami ekperymentalnymi uzyskując dobrą zgodność.
Źródło:
Journal of Theoretical and Applied Mechanics; 1999, 3; 707-728
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Facile Method for the Production of Sn-Ag Alloy by High Energy Ball Milling
Autorzy:
Sharma, Ashutosh
Ahn, Byungmin
Powiązania:
https://bibliotekanauki.pl/articles/353739.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Pb-free
solder
electronics
ball milling
microstructure
Opis:
In this study, we have developed Sn-Ag alloy by a simple high energy ball milling technique. We have ball-milled the eutectic mixture of Sn and Ag powders for a period of 45 h. The milled powder for 45 h was characterized for particle size and morphology. Microstructural investigations were carried out by scanning electron microscopy and X-ray diffraction studies. The melting behavior of 45 h milled powder was studied by differential scanning calorimetry. The resultant crystallite size ofthe Sn(Ag) solid solution was found to be 85 nm. The melting point of the powder was 213.6°C after 45 h of milling showing depression of ≈6°C in melting point as compared to the existing Sn-3.5Ag alloys. It was also reported that the wettability of the Sn-3.5Ag powder was significantly improved with an increase in milling time up to 45 h due to the nanocrystalline structure of the milled powder.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 4; 1329-1333
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model of degree of scattering polarization for oil spilling
Autorzy:
Wang, Xiao
Xu, Jiang
Qian, Weixian
Ouyang, Jingyi
Powiązania:
https://bibliotekanauki.pl/articles/1835805.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical mechanism
surface microstructure
degree of scattering polarization
Fresnel formula
oil slick
Opis:
Oil slicks often show uncertain surface roughness and Fresnel reflection parameters. Consequently, differentiating oil spilled on the seawater in these areas using optical sensors is a challenge. Therefore, the optical mechanism of the oil film has been studied by the Maxwell equation. It is found that the polarization characteristics of the oil slicks can help us to overcome this problem. According to the Fresnel formula, the scattering coefficient and scattering rate of the homogeneous oil film have been deduced, and the phase difference of the scattering electromagnetic wave has also been calculated to verify the accuracy of the model. The parameter, a degree of scattering polarization, has been derived to identify the oil slicks on the sea wave. It depends on accurately knowing the Stokes parameter for the reflected light, and varies with the refractive index of the surface layer and viewing angles. The actual spilled oil has been measured by this model, and the oil film can be accurately identified at various angles. These preliminary results suggest that the potential of multi-angle polarization measurement of ocean surface needs further researches.
Źródło:
Optica Applicata; 2020, 50, 3; 433-445
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A review of process parameters in friction drilling on joining of steels
Autorzy:
Selvaraj, R.M.
Hynes, N.R.J.
Powiązania:
https://bibliotekanauki.pl/articles/24200610.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
friction drilling
conical tool
bushing length
microstructure
machining parameters
wiercenie tarciowe
narzędzie stożkowe
długość tulei
mikrostruktura
parametry obróbki
Opis:
Purpose: Friction drilling is a unique way of creating holes in steel. In a solitary advance, a rotating conical tool is utilized to enter by penetrating as an opening on the surface of the sheet and making a bushing without making a chip. During this process, the heat produced by the frictional power linking the device and the sheet metal workpiece is used to pierce and make a bushing out of work. The goal of this novel hole-making process is to improve the bushing length in the thin-walled sheet metals by forming a bush and then combining thin sheet metals. The inconceivable utilizations of warm grating penetrating in a few modern areas will introduce another period of interfacing processes for different work materials in automobiles. Design/methodology/approach: Researchers have undergone numerous experiments based on the machining parameters, including spindle speed, feed rates, Friction Contact Ratio (FACR), tool angle, tool diameter, sheet thickness, and the output of the friction drilling, includes the bushing length, surface roughness, tool wear, hardness, thrust force, torque and microstructural evaluation. Findings: The crucial concerns that should be addressed and researched by researchers in the near future, such as determining the optimal machining parameters of such process and analysing, bushing length, microstructural impacts on the many aspects and their performance, are highlighted. Research limitations/implications: This research paper tends to examine the advancements in research on the friction drilling method and its applications, taking into account the benefits and limits of friction drilling. Practical implications: The present paper identifies the machining parameters and their contribution towards the output level of various materials like Stainless steel, Brass, aluminium, titanium, tempered steel and nickel-based compounds of different thickness. Originality/value: The machining parameters like spindle speeds, feed rate, tool angles, thrust force, Torque, surface roundness, bushing height, frictional heat and tool diameter are optimized in the friction drilling. The incorrect bushing is formed due to the high thrust force, and Low temperatures cause ductility and softening issues.
Źródło:
Archives of Materials Science and Engineering; 2022, 119, 1; 12--20
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Simulation and Experimental Investigation of the Thermal Characteristics of Refractory Bricks Produced Using Fireclay and Agroforestry Wastes
Autorzy:
Obidiegwu, Eugenia Obiageli
Esezobor, David Ehigie
Mgbemere, Henry Ekene
Odili, Cletus Chiosa
Powiązania:
https://bibliotekanauki.pl/articles/2105205.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
simulation
insulating bricks
microstructure
thermal characteristics
Opis:
Manufacturing and processing industries usually consume large quantities of materials and energy in the course of their operations. The energy supplied for high-temperature processes are used partially for the actual technical process and between 30 to 40% of the energy escapes through the walls of the reactor into the atmosphere, leading to a high degree of thermal inefficiency and fuel consumption. This paper studies the thermal behaviour of insulating refractory bricks produced from a blend of fireclay and agroforestry wastes. The fireclays used were obtained from Ukpor deposit in Anambra State (Latitude 5.95°N, Longitude 6.92°E), Osiele deposit in Abeokuta, Ogun State (Latitude 7.18°N, Longitude 3.45°E) and Kankara Katsina State (Latitude 11.93°N, Longitude 7.41°E), all of which are in Nigeria. Samples were prepared with various weight percentages (60–100 wt.%) clays and (0–40 wt.%) of agroforestry waste, with grain sizes between 212 and 600 µm. Raw materials and the developed refractory bricks were characterised using appropriate standard techniques. The chemical, mineralogical constituents and phases present in the microstructure were examined. Physical and thermo-mechanical properties were investigated. The insulating refractory bricks developed have porosity of 78.83% , cold crushing strength (CCS) 3.144 kN/m2 and thermal conductivity 0.04–0.046 W/(m∙K) that compare favourably with imported bricks 75–85%, 2.756 kN/m2 and 0.049 W/(m∙K) in both physical, mechanical and thermal properties respectively. The reason is that the agroforestry waste used (coconut shell), served to create the pores that improve insulation after burning. Also the ash that remains serves as reinforcement to improve the mechanical properties. The thermal behaviour of the bricks was studied using Finite Element Method and shows a strong correlation with the experimental findings. This indicates that the produced insulating bricks have the thermal properties required for insulation of furnaces.
Źródło:
Journal of Casting & Materials Engineering; 2022, 6, 2; 45--57
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study of Microstructure and Porosity Formation in High-Pressure Die-Casting
Autorzy:
Matejka, Marek
Bolibruchová, D.
Podprocká, R.
Powiązania:
https://bibliotekanauki.pl/articles/2126896.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Si-Cu alloy
high-pressure die casting
returnable material
numerical simulation
porosity
microstructure
stop Al-Si-Cu
odlewanie wysokociśnieniowe
odzysk materiału
symulacja numeryczna
porowatość
mikrostruktura
Opis:
The technology of high-pressure die-casting (HPDC) of aluminum alloys is one of the most used and most economical technology for mass production of castings. High-pressure die-casting technology is characterized by the production of complex, thin-walled and dimensionally accurate castings. An important role is placed on the effective reduction of costs in the production process, wherein the combination with the technology of high-pressure die-casting is the possibility of recycling using returnable material. The experimental part of the paper focuses on the analysis of a gradual increase of the returnable material amount in combination with a commercial purity alloy for the production of high-pressure die-castings. The returnable material consisted of the so-called foundry waste (defective castings, venting and gating systems, etc.). The first step of the experimental castings evaluation consisted of numerical simulations, performed to determine the points of the casting, where porosity occurs. In the next step, the evaluation of areal porosity and microstructural analysis was performed on experimental castings with different amounts of returnable material in the batch. The evaluation of the area porosity showed only a small effect of the increased amount of the returnable material in the batch, where the worst results were obtained by the casting of the alloy with 90% but also with 55% of the returnable material in the batch. The microstructure analysis showed that the increase in returnable material in the batch was visibly manifested only by a change in the morphology of the eutectic Si.
Źródło:
Archives of Foundry Engineering; 2021, 21, 4; 127--130
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Abrasion Resistance of S235, S355, C45, AISI 304 and Hardox 500 Steels with Usage of Garnet, Corundum and Carborundum Abrasives
Autorzy:
Szala, Mirosław
Szafran, Michał
Macek, Wojciech
Marchenko, Stanislav
Hejwowski, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/103045.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
abrasion
wear resistance
dry sand-rubber wheel test
garnet
aluminum oxide
silicon carbide
steel
hardness
microstructure
odporność na ścieranie
test koła suchy piasek-guma
granat
tlenek glinu
węglik krzemu
stal
twardość
mikrostruktura
Opis:
The steel presents a wide field of application. The abrasive wear resistance of steel relies mainly on the microstructure, hardness as well as on the abrasive material properties. Moreover, the selection of a abrasion-resistant grade of steel still seems to be a crucial and unsolved problem, especially due to the fact that the actual operating conditions can be affected by the presence of different abrasive materials. The aim of this work was to determine the effect of different abrasive grit materials i.e. garnet, corundum and carborundum on the abrasive wear result of a commonly used in industry practice steels i.e. S235, S355, C45, AISI 304 and Hardox 500. The microstructure of the steel was investigated using light optical microscopy. Moreover, hardness was measured with Vickers hardness tester. Additionally, the size and morphology of the abrasive materials were characterized. The abrasion tests were conducted with the usage of T-07 tribotester (dry sand rubber wheel). The results demonstrate that the hardness and structure of steels and hardness of abrasive grids influenced the wear results. The abrasive wear behavior of steels was dominated by microscratching and microcutting wear mechanisms. The highest mass loss was obtained for garnet, corundum, and carborundum, respectively. The usage of various abrasives results in different abrasion resistance for each tested steel grade. The AISI 304 austenitic stainless steel presents an outstanding abrasive wear resistance while usage of corundum and Hardox 500 while using a garnet as abrasive material. The C45 carbon steel was less resistant than AISI 304 for all three examined abrasives. The lowest resistance to wear in garnet and carborundum was obtained for the S235JR and S355J2 ferritic-perlitic carbon steels and in corundum for Hardox 500 which has tempered martensitic structure.
Źródło:
Advances in Science and Technology. Research Journal; 2019, 13, 4; 151-161
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Accounting for the Inhomogeneity of Deformation in Identification of Microstructure Evolution Model
Niejednorodność odkształcenia w identyfikacji modelu rozwoju mikrostruktury
Autorzy:
Szeliga, D.
Kuziak, R.
Kopp, R.
Smyk, G.
Pietrzyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/353715.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microstructure
two-step compression test
deformation
mikrostruktura
dwuetapowa osiowosymetryczna próba ściskania
odkształcenia
Opis:
The paper deals with the problem of identification of microstructure evolution model on the basis of two-step compression test. Classical interpretation of this test assumes uniform fields of strains, stresses and temperatures in the deformation zone and calculates the coefficients in the model on the basis of force measurements in the second step. In the present paper the inverse approach was applied. Finite element (FE) simulations of the compression test were performed and local values of microstructural parameters were determined accounting for the inhomogeneity of deformation. Objective function was formulated as the Euclid norm for the error between measured and calculated forces for various interpass times. Coefficients in the microstructure evolution model were determined by searching for the minimum of the objective function. Optimized model was validated in simulations of plane strain compression tests.
W artykule poruszono problem identyfikacji parametrów modelu rozwoju mikrostruktury na podstawie dwuetapowej osiowosymetrycznej próby ściskania. Klasyczna interpretacja wyników tej próby zakłada w strefie odkształcenia jednorodne pole odkształceń, naprężeń oraz temperatury, a parametry modelu są wyznaczane na podstawie pomiarów sił w drugim etapie ściskania. W pracy do oszacowania wartości parametrów zastosowano metodę odwrotną. Wykonano symulacje metodą elementów skończonych oraz wyznaczono lokalne wartości parametrów mikrostruktury uwzględniając nierównomierność odkształcenia. Funkcja celu została zdefiniowana jako odległość Euklidesowa między siłami obliczonymi i zmierzonymi w próbie dwuetapowego ściskania dla różnych długości przerw pomiędzy odkształceniami. Parametry modelu mikrostruktury oszacowano poprzez wyznaczenie minimum funkcji celu. Model z wyznaczonymi parametrami został zweryfikowany w próbie ściskania w płaskim stanie odkształcenia.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 4; 3087-3094
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 1619

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