oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 28 )

2019 ( 233 )

2018 ( 320 )

2017 ( 296 )

Custom range...

Search Results: 1 - 10 of 297583 matches for " J. Konieczny "
All listed articles are free for downloading (OA Articles)
Page 1 /297583
Display every page Item
Application of the artificial neural networks for prediction of hardness of alloyed copper
J. Konieczny
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: The aim of the work is to employ the artificial neural networks for prediction of hardness of the alloyed copper like CuTi, CuFe, CuCr and CuNiSi.Design/methodology/approach: It has been assumed that the artificial neural networks can be used to assign the relationship between the chemical compositions of alloyed copper, temperature and time of solution heat treatment, degree of cold working deformation and temperature and time of ageing. In order to determine the relationship it has been necessary to work out a suitable calculation model. It has been proved that employment of genetic algorithm to selection of input neurons can be very useful tool to improve artificial neural network calculation results. The attempt to use the artificial neural networks for predicting the effect of the chemical composition and parameters of heat treatment and cold working deformation degree on the hardness succeeded, as the level of the obtained results was acceptable. Findings: Artificial neural networks, can be applied for predicting the effect of the chemical composition, parameters of heat treatment and cold working deformation degree on the hardness. Research limitations/implications: Worked out model should be used for prediction of hardness only in particular groups of alloyed copper, mostly because of the discontinuous character of input data.Practical implications: The results of research make it possible to calculate with a certain admissible error the hardness value basing on combinations of concentrations of the particular elements, heat treatment parameters and cold working deformation degree.Originality/value: In this paper it has been presented an original trial of prediction of the required hardness of the alloyed copper like CuTi, CuFe, CuCr and CuNiSi.
Misorientation in rolled CuTi4 alloy
J. Konieczny,Z. Rdzawski
Archives of Materials Science and Engineering , 2011,
Abstract: Purpose: The aim of the work is to investigate the microstructure heat treated and cold rolled commercial copper alloy CuTi4.Design/methodology/approach: The Investigations of the structure were made on ZEISS SUPRA 25 with EBSD method. Observations of the structure on thin foils were made on the JOEL 3010 transmission electron microscope (TEM).Findings: Decomposition of supersaturated solid solution in that alloy is similar to the alloys produced in laboratory scale. The observed differences in microstructure after supersaturation were related to the presence of undissolved Ti particles and increased segregation of titanium distribution in copper matrix including microareas of individual grains. The mentioned factors influence the mechanism and kinetics of precipitation and subsequently the produced wide ranges of functional properties of the alloy.Research limitations/implications: Cold deformation (50% reduction) of the alloy after supersaturation changes the mechanism and kinetics of precipitation and provides possibilities for production of broader sets of functional properties. It is expected that widening of the cold deformation range should result in more complete characteristics of material properties, suitable for the foreseen applications. Similar effects can be expected after application of cold deformation after ageing.Practical implications: The elaborated research results present some utilitarian qualities since they can be used in development of process conditions for industrial scale production of strips from CuTi4 alloy of defined properties and operating qualities.Originality/value: The mentioned factors influence the mechanism and kinetics of precipitation and subsequently the produced wide ranges of functional properties of the Cu-Ti alloys.
Influence of cold working on microstructure and properties of annealing CuTi4 alloy
J. Konieczny,Z. Rdzawski
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: The aim of this study was to investigate the effect of cold plastic deformation of the supersaturation on the structure and properties of the CuTi4 alloy after aging.Design/methodology/approach: CuTi4 alloy of supersaturation temperature of 900°C after heating for 1 hour. After solutioning alloy was processed in two ways: first aged in the temperature range 450-600°C and the second stage rolling reduction with Z=50%, and then aged in the temperature range 450-600°C.Findings: The results confirmed that the temperature within the range 500-600oC, the hardness increases with increasing aging time until reaching the maximum, but then with increasing aging time the hardness decreases. By using methods of electron microscopy (SEM, EDS, EBSD, TEM) after aging at 550°C after 1 minute of modulated microstructure was observed - characteristic for the spinodal transformation and lamellar, formed by nucleation and growth. Research limitations/implications: A widely used method for increasing the strength properties of metal alloys, in addition to cold plastic deformation, is the strengthening of new phases separated particles during aging. The effect of cold rolling operation between solutioning and aging on microstructure and properties of alloyed copper CuTi4. Further examination also included the effect of time and aging temperature.Practical implications: On the basis of conductivity, the influence of cold plastic deformation and subsequent aging on the hardness and electrical conductivity of the alloy CuTi4. It was found that with increasing aging time and with increasing aging temperature increases electrical conductivity of the alloy. On the basis of X-rays can be concluded that in alloyed copper containing 4% Ti and precipitation hardening metastable phase β’-Cu4Ti is separated, which occurs both in the previously deformed and undeformed cold worked alloy.Originality/value:
Stereometry specification of anodisation surface of casting aluminium alloys
J. Konieczny,K. Labisz,J. Wieczorek,L. A. Dobrzański
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The aim of the work is presents the influence of casting method and anodic treatment parameters on properties of an anodic layer formed on aluminum casting alloys.Design/methodology/approach: Investigations were carried out on the laser profile measurement gauge MicroProf from company FRT on two casting aluminum alloys which both were founding by pressure die casting and gravity casting.Findings: The researches included analyze of the influence of chemical composition, geometry and roughness of anodic layer obtained on aluminum casts.Research limitations/implications: Contributes to research on anodic layer for aluminum casting alloys.Practical implications: Conducted investigations lay out the areas of later researches, especially in the direction of the possible, next optimization anodization process of aluminum casting alloys, e.g. in the range of raising resistance on corrosion.Originality/value: The range of possible applications increases for example as materials on working building constructions, elements in electronics and construction parts in air and motorization industry in the aggressive environment.
Thermomechanical processing of CuTi4 alloy
Z. Rdzawski,J. Stobrawa,W. G?uchowski,J. Konieczny
Journal of Achievements in Materials and Manufacturing Engineering , 2010,
Abstract: Purpose: One of the reasons behind the interest in copper titanium alloys was development of new materials to substitute copper beryllium alloys. The reason for selecting that material for studies was that in the early stages of decomposition of CuTi4 alloy a spinodal transformation takes place and ordering processes begin. Proper selection of heat treatment and plastic working conditions provides possibilities to produce very wide range of sets of properties by formation of the required alloy microstructure. Therefore the main objective of the study was to capture the changes in precipitation kinetics, especially in the relations between supersaturation and ageing or between supersaturaion, cold deformation and ageing in connection to the changes in microstructure and functional properties (mainly changes in hardness and electrical conductivity).Design/methodology/approach: Melting of the charge material was conducted in medium-frequency induction furnace, in a graphite crucible. The melted material after bath preparation was poured into a cast iron ingot mould (with graphite grease applied on the inside) of dimensions 35 x 120 x 250 mm. The ingots after casting were peeled. The treated ingots were heated in resistance furnace at 900oC for 1.5 hour and rolled down on a reversible two-high mill.Findings: Decomposition of supersaturated solid solution in that alloy is similar to the alloys produced in laboratory scale. The observed differences in microstructure after supersaturation were related to the presence of undissolved Ti particles and increased segregation of titanium distribution in copper matrix including microareas of individual grains. The mentioned factors influence the mechanism and kinetics of precipitation and subsequently the produced wide ranges of functional properties of the alloy.Research limitations/implications: Cold deformation (50% reduction) of the alloy after supersaturation changes the mechanism and kinetics of precipitation and provides possibilities for production of broader sets of functional properties. It is expected that widening of the cold deformation range should result in more complete characteristics of material properties, suitable for the foreseen applications. Similar effects can be expected after application of cold deformation after ageing.Practical implications: The elaborated research results present some utilitarian qualities since they can be used in development of process conditions for industrial scale production of strips from CuTi4 alloy of defined properties and operating qualities.Originality/value: T
Anodization of cast aluminium alloys produced by different casting methods
K. Labisz,L.A. Dobrzański,J. Konieczny
Archives of Foundry Engineering , 2008,
Abstract: In this paper the usability of two casting methods, of sand and high pressure cast for the anodization of AlSi12 and AlSi9Cu3 aluminium cast alloys was investigated. With defined anodization parameters like electrolyte composition and temperature, current type and value a anodic alumina surface layer was produced. The quality, size and properties of the anodic layer was investigated after the anodization of the chosen aluminium cast alloys. The Alumina layer was observed used light microscope, also the mechanical properties were measured as well the abrasive wear test was made with using ABR-8251 equipment. The researches included analyze of the influence of chemical composition, geometry and roughness of anodic layer obtained on aluminum casts. Conducted investigations shows the areas of later researches, especially in the direction of the possible, next optimization anodization process of aluminum casting alloys, for example in the range of raising resistance on corrosion to achieve a suitable anodic surface layer on elements for increasing applications in the aggressive environment for example as materials on working building constructions, elements in electronics and construction parts in air and automotive industry.
Magnetic properties of hot pressed powder Co68Fe4Mo1Si13.5B13.5 alloy
J. Konieczny,L.A. Dobrzański,I. Wnuk
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: The aim of the work is to investigate the structure and magnetic properties of the cobalt based hot pressed Co68Fe4Mo1Si13.5B13.5 powder obtained in high-energy ball milling process.Design/methodology/approach: The nanocrystalline ferromagnetic powders were manufactured by high-energy ball milling of metallic glasses ribbons in as state. The hot pressing process was made on machine “Degussa”. Observations of the structure of die stampings were made on the OPTON DSM-940 scanning electron microscope. Graphical analyses of the obtained X-ray diffraction patterns, as well as of the HC=f(TA) relationship were made using the MICROCAL ORIGIN 6.0 program.Findings: The analysis of the magnetic properties and structure of the die stamping out that compared to the magnetic properties of the amorphous ribbons as their precursor, that hot pressing process deteriorates their magnetically soft properties.Research limitations/implications: For the metallic Co-based amorphous ribbons, further mechanical and structure examinations are planed.Practical implications: Structure and magnetic properties analysis of die stampings of powdered amorphous metallic ribbons is helpful to prepare this material by laboratory methods. Feature an alternative to commercial alloys and composite materials are the amorphous and nanocrystalline metal amorphous ribbons obtained by melt spinning technique and make it possible to obtain the new composite materials with best magnetic properties, which dimensions and shape can be freely formedOriginality/value: The paper presents influence of hot pressing parameters process of metallic powdered ribbons on structure and magnetic properties of obtained die stampings.
The investigation of microstructure and hardness of archaeological alloys
J. Konieczny,?. Kondzio?ka,I. M?odkowska-Przepiórowska
Journal of Achievements in Materials and Manufacturing Engineering , 2011,
Abstract: Purpose: The aim of the work was to investigate the microstructure and hardness of archaeological metal.Design/methodology/approach: The investigations of the microstructure were made on ZEISS SUPRA 25 with EDX method. Investigation of structure were made on PANalytical’s X’Pert diffractometer.Findings: Metallographic studies were carried out on archeological finds that have been extracted from the ground during excavations on the market in Czestochowa (Poland) during the summer of 2009. In addition to the remains of buildings discovered under the level of market research objects were excavated in the area. Preliminary dating of the material shows a broad interval.Research limitations/implications: In the examined finds the main component is copper, but they also contain other elements, sometimes in large numbers, that indicates a very low-purity metallurgical material and thus proves that this is not a typical bronze how manufactured at that time. The metal nails are characterized by high purity metallurgical.Practical implications: The presented results are an important contribution to the accurate characterization of found objects and also can help to determine more accurately determine their age and use in daily life of ancestors.Originality/value: These factors indicate new areas of research in materials science that significantly enrich the knowledge of times past.
Structure and magnetic properties of hot pressed powder Co77Si11.5B11.5 alloy
J. Konieczny,I. Wnuk,L.A. Dobrzański
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The aim of the work is to investigate the structure and magnetic properties of the cobalt based hot pressed Co77Si11.5B11.5 powder obtained in high-energy ball milling process.Design/methodology/approach: The nanocrystalline ferromagnetic powders were manufactured by high-energy ball milling (SPEX 8000 mill) of metallic glasses ribbons in as state. The hot pressing process was made on machine “Degussa”. Observations of the structure of die stampings were made on the OPTON DSM-940 and ZEISS SUPRA 35 scanning electron microscope. Tests of magnetic properties were carried out by the use of Lake Shore’s Vibrating Sample Magnetometer VSM model 7307.Findings: The analysis of the results enabled determination of the hot pressing parameters on magnetic properties and structure of obtained stampings.Research limitations/implications: For the metallic Co-based amorphous ribbons, further mechanical and structure examinations are planed.Practical implications: Structure and magnetic properties analysis of die stampings of powdered amorphous metallic ribbons is helpful to prepare this material by laboratory methods. Feature an alternative to commercial alloys and composite materials are the amorphous and nanocrystalline metal amorphous ribbons obtained by melt spinning technique and make it possible to obtain the new composite materials with best magnetic properties, which dimensions and shape can be freely formed.Originality/value: The paper presents influence of hot pressing parameters process of metallic powdered ribbons Co77Si11.5B11.5 on structure and magnetic properties of obtained die stampings.
The influence of Ni-P layer deposited onto Al2O3 on structure and properties of Al-Al2O3 composite materials
L.A. Dobrzański,M. Kremzer,J. Konieczny
Journal of Achievements in Materials and Manufacturing Engineering , 2011,
Abstract: Purpose: The purpose of this work is to present the influence of wettability improvement of sintered Al2O3 particles by deposition of Ni-P coating.Design/methodology/approach: The material for investigations was manufactured by pressure infiltration method of ceramic porous preforms. The eutectic aluminium alloy EN AC - AlSi12 was use as a matrix while as reinforcement were used ceramic preforms manufactured by sintering of Al2O3 Alcoa CL 2500 powder with addition of pore forming agents as carbon fibres Sigrafil C10 M250 UNS, SGL Carbon Group Company. The Al2O3 was coated with the Ni-P alloy to improve the wettability of sintered particles. Metallographic examinations were made in the transmission electron microscope (TEM).Findings: The obtained results indicate the possibility of obtaining new materials with all advantageous properties of the particular composite constituents by infiltration of the ceramics with the liquid aluminium alloy.Practical implications: The composite materials made by the developed method can find application as the alternative material for elements fabricated from conventional materials.Originality/value: The obtained results show the possibility of manufacturing the composite materials by the pressure infiltration method of porous sintered preforms based on the ceramic particles with liquid aluminium alloy being a cheaper alternative for materials reinforced by fibres.
Page 1 /297583
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.