Wyniki wyszukiwania - Biblioteka Nauki

1

Methods of data mining for modelling of low-pressure heat treatment

100%

Wołowiec-Korecka E.

Journal of Achievements in Materials and Manufacturing Engineering

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2017

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tom Vol. 85, nr 1

31--40

EN

Purpose: This paper addresses the methods of the modelling of thermal and thermochemical processes used in computer-aided design, optimization and control of processes of thermal and thermochemical treatment in terms of obtaining real-time results of the calculations, which allows for observation of how an item changes during its treatment to respond immediately and to determine the parameters of a corrective process should any irregularities be detected. The main goal of the literature review was to develop a methodology for the design of functional and effective low-pressure processes of thermal and thermochemical treatments using effective calculation methods. Design/methodology/approach: A detailed analysis was conducted regarding the modelling methods with low-pressure carburizing and low-pressure nitriding. Findings: It was found the following criteria of methods selection of heat treatment modelling should be applied: data quality, data quantity, implementation speed, expected relationship complexity, economic and rational factors. Practical implications: Because of its non-equilibrium nature and transient states in the course of the processes computational support is particularly required in low-pressure thermochemical treatments. The primary goal of the simulation is to predict the course of the process and the final properties of the product, what ensures the repeatability of the process results. Originality/value: It was presented a synthetic presentation of modelling methods, in particular methods of artificial intelligence; it was also analysed the possibilities and risks associated with methods.

2

Case hardening development review (2001-2020)

100%

Wołowiec-Korecka E.

Archives of Materials Science and Engineering

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2023

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tom Vol. 120, nr 2

70--85

EN

Purpose: The purpose of the work is a complex review of methods applied industrially as case hardening. The paper contains an overview of scientific and development works on surface case hardening methods, especially carburising and quenching, described in the literature from 2001-2020. Design/methodology/approach: State-of-the-art was reviewed by a critical review of the world literature published in 2001-2022, including theoretical work, scientific research, and industry reports. An additional examination of the state of the art was conducted in terms of patent works. Findings: The period of 2001-2020 was a time of intensive work on the modernisation of case hardening techniques to improve the repeatability and uniformity of the produced layers and minimise deformations after hardening. Developing computing technologies have played a large part in this progress. New technologies have also been developed. Research limitations/implications: The review of papers and patent databases was limited to databases providing English-language content options. Practical implications: Case hardening is a crucial stage of steel heat treatment in almost every industrial branch: mechanical, tool, automotive, railway, and aviation. Originality/value: A synthetic review of case hardening methods was presented, particularly carburizing and quenching methods; it also analysed the possibilities and directions of their development.

3

Influence of number of fusions on mechanical properties of Ducinox alloy

63%

Klimek L. , Wołowiec-Korecka E.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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tom Vol. 78, nr 1

21--24

EN

Purpose: The purpose of the test was to specify influence of re-fusions of the nickelchromium prosthetic alloy Ducinox on its strength properties. Design/methodology/approach: The tests were carried out on the samples cast of the Ducinox alloy molten once, twice and three times. The hardness has been measured using the Vickers method; the tensile strength has been also specified. The samples designed for strength tests were subjected to X-ray control to find possible defects that would eliminate the samples from further tests. The last test was observation of fractures occurred as a result of the strength tests, under the microscope. Findings: Both hardness measurements and strength tests did not show statistically significant differences among individual groups of samples. Practical implications: Based on the results of the tests carried out, it can be found that re-fusion of the alloy Ducinox has no influence on its tensile strength. Thereby, in the dental technology practice, it is possible to add the casting scrap to pure metallic alloy without influence on strength of prosthetic element castings. Originality/value: This is an well-known method of analysis which is applied in many scientific fields. However in modern prosthetics it is new approach.

4

Field tests of components regenerated using the MULTIPLEX technology

51%

Klimek L. , Krasiński A. , Wołowiec-Korecka E.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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tom Vol. 78, nr 2

59--64

EN

Purpose: The purpose was to show the results of the field tests of components carried out using the MULTIPLEX technology. Design/methodology/approach: The field tests have been carried out on the following components: brake expanders of Mercedes bus, a pintle of the tram trolley component, a pin from a casting cleaning plant element. Each of the tested elements was subject to regeneration through steel surfacing by welding and then chemical and heat treatment. The regenerated elements were compared with original ones working at the same service conditions. Findings: The findings have shown significant prolongation of life of the components regenerated using the MULTIPLEX technology in relation to the original components. Research limitations/implications: The shown regeneration technology is the cost effective way to restore the suitable performance traits or to ensure preventively the suitable properties by initial protection of newly manufactured elements or regeneration of old ones within the framework of recovery procedure. Originality/value: The shown regeneration method is the advanced technology combining welding with chemical and heat treatment.

5

2D-Finite element analysis of inlay-, onlay bridges with using various materials

51%

Śmielak B. , Świniarski J. , Wołowiec-Korecka E. , Klimek L.

Archives of Materials Science and Engineering

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2016

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tom Vol. 79, nr 2

71--78

EN

Purpose: To compare the impact of different bridge constructions and different loads on stress distribution in bridges. Design/methodology/approach: The study was conducted on 96 computer models of both premolars and molars that simulated a missing second premolar restored with a bridge supported on crown inlays or onlays. Simulations were made of a bridge constructed from four different materials: Au alloy, Cr/Ni alloy as well as two kinds of glass fibre-reinforced composites: Targis Vectris and FibreKor /Sculpture. The study was conducted using the finite element method (FEM). The results were analysed with PQStat statistical software version 1.6. Findings: In none of the analysed cases did stresses appear capable of damaging the bridge construction. Reduced stresses were lower in glass fibre reinforced composite materials than in metal alloys. Practical implications: The force application point has a decisive influence on stress distribution in the hard dental tissue and in bridges. The highest stress values occurred at the loading of the pontic tooth. Originality/value: The force application point has a decisive influence on stress distribution in the hard dental tissue and in bridges. The highest stress values occurred at the loading of the pontic tooth.

6

The role of mechanical, chemical and physical bonds in metal-ceramic bond strength

51%

Czepułkowska W. , Wołowiec-Korecka E. , Klimek L.

Archives of Materials Science and Engineering

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2018

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tom Vol. 92, nr 1

5--14

EN

Purpose: A review regarding the mechanisms of metal-ceramic join is presented. Design/methodology/approach: The impact of the air-abrasion parameters on the mechanical bond strength of the ceramic crowns was discussed. The presence of opaque on the chemical bond was analysed. Research of the influence of the difference in the coefficient of thermal expansion values on the metal-ceramic bond was included. The methods of testing the bond strength were analysed. Findings: The metal substructure-dental ceramic bond strength is affected by all types of bond. In bond strength, 3-point bending test and shear test are mainly used. Created samples simulate the ceramic crowns veneered on one side. The role of physical bond on ceramic crowns veneered around metal substructure is unknown. Research limitations/implications: The prosthetic restorations with the ceramic surrounding whole the metal substructure are commonly used. The impact of shrinkage in the cylindrical deposition of the ceramic on metal substructure should be analysed. Practical implications: Numerical analysis and FEM simulation can be helpful in the analysis of the physical bond between the metal substructure and the dental ceramic around it. Originality/value: The impact of the type of the bond to metal-ceramic bond strength is presented, taking into account the cognitive gap in the influence of the coefficient of thermal expansion on the cylindrical placement of ceramic on the substructure.

7

Study on homogeneity and repeatability of single-piece flow carburizing system

51%

Madej A. , Brewka A. , Wołowiec-Korecka E.

Journal of Achievements in Materials and Manufacturing Engineering

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2017

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tom Vol. 84, nr 2

68--75

EN

Purpose: The purpose of this paper was to determine the homogeneity and replicability of carburized layers obtained by a continuous single-piece flow method. Design/methodology/approach: A series of 100 gears was carburized under low pressure atmosphere using the single-piece flow method. The microstructures of the obtained carbon layers were investigated. Hardness penetration pattern and carbon concentration profiles were tested. Findings: The findings have shown the validity/correctness of the microstructures of the carburized layers obtained by the single-piece flow method. It has been proved that the carbon layer in every gear is uniform, what confirms that each element is affected by the same process conditions and the gears in the whole series can be precisely reproduced. Research limitations/implications: The short-pulse low-pressure carburizing technology needs further investigation to understand its all mechanisms fully. Practical implications: The single-piece flow method provides the uniform and reproducible carburized layers with the precision magnitude exceeding the abilities of currently used thermo-chemical furnaces. When applying the method it is possible to obtain a uniform carburized case in every single gear from the whole series of elements subjected to the process. Optimized configuration of process parameters and carbon-carrying mixture allows to meet the high expectations of a modern and future industry, what is most crucial in exploiting carburized steel gears. Originality/value: The applicability of the LPC single-piece flow method to a demanding mass production has been verified. The statistical validity of research results of the whole manufactured series of gears is being performed for the first time.

8

Impact of single-piece flow thermo-chemical treatment process conditions on hole quenching deformation

51%

Stachurski W. , Sawicki J. , Zgórniak P. , Wołowiec-Korecka E.

Archives of Materials Science and Engineering

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2023

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tom Vol. 121, nr 1

18--24

EN

Purpose: Pulsed low-pressure carburizing (LPC) and omnidirectional high-pressure gas quenching (HPGQ) are innovative methods for quenching the surface layer. The thermo-chemical treatment carried out by this method reduces quenching geometric deformations, with detailed numerical values not available in the literature due to the short existence of this method. Design/methodology/approach: Sixteen toothed elements of EN 20MnCr5 steel were subjected to pulsed low-pressure carburising with omnidirectional jet quenching in 4 groups, varying the process temperature (920°C, 960°C) and in two groups performing a tempering treatment. The elements were tested before machining by measuring their internal hole diameters, radial runout, roundness and cylindricity. These values were tested again after treatment. The direction of change and the statistical significance of the effect of treatment and its parameters, temperature and tempering were analysed. Findings: Thermo-chemical treatment significantly affects geometric changes in diameters, roundness, cylindricity and radial runout compared to elements without heat treatment due to physical transformations occurring during this treatment (p<0.05). Changing the process temperature in the value range of 920°C-960°C affects the hole diameter (makes it smaller) (p<0.05), but does not affect radial runout, cylindricity and roundness. The observed dimensional changes in diameters have numerically small values (<0.005 mm). The tempering treatment can affect the values of average diameters. Its effect on roundness, cylindricity and radial runout was not observed. Research limitations/implications: In the temperature range studied, the method of pulsed low-pressure carburising + omnidirectional high-pressure gas quenching makes it possible to raise the temperature of the process and shorten its duration without significant geometric changes in the treated elements. Practical implications: The method of pulsed low-pressure carburising and omnidirectional high-pressure gas quenching (HPGQ) ensures the maintenance of reproducible quenching deformations at a level significantly lower than conventional processing methods. Originality/value: The method of pulsed low-pressure carburising together with omnidirectional high-pressure gas quenching (HPGQ) is a method that has been used briefly in the industry, and there are few reports on it to date.

9

Devices for modern vacuum heat treatment

51%

Korecki M. , Brewka A. , Wołowiec-Korecka E.

Archives of Materials Science and Engineering

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2019

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tom Vol. 95, nr 2

77--85

EN

Purpose: A review regarding the devices for vacuum heat treatment is presented. Design/methodology/approach: Devices for modern heat treatment has been reviewed. The devices has been classified regarding the heat treatment (quenching, carburizing, nitriding, tempering and annealing). The possible application, materials and parts for heat treatment as well as parameters of the devices has been analysed. Findings: There is a wide range of modern vacuum heat treatment devices. All currently used heat and thermo-chemical treatments may be proceed in vacuum equipment. It is also in many cases preferable to use vacuum- because of economic reasons, better metallurgical results or environmental friendliness. Also software simulators which facilitates the planning of heat treatment are available with the equipment. Practical implications: Because of the industry expectations regarding efficiency, quality, economy and safety, vacuum equipment becoming the subject of wider and wider attention. In particular, aerospace and automotive industries pay a lot of attention to these aspects. The basic task of vacuum devices is fast, effective, environmentally friendly production of high quality machine parts. Originality/value: The synthetic presentation of modern devices for vacuum heat treatment was presented, in particular furnaces for quenching, carburizing, nitriding, tempering and annealing. The products characteristic and applications has been presented. Also equipment for some advanced vacuum applications has been presented. Modern software which complements the devices in terms of designing heat treatment processes has been described.

10

Modelowanie wytrzymałości połączenia podłoża metalowego z ceramiką dentystyczną w zależności od parametrów uprzedniej obróbki strumieniowo-ściernej

51%

Pietnicki K. , Wołowiec-Korecka E. , Klimek L.

Mechanik

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2015

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tom R. 88, nr 8-9CD1

266--269

PL

W pracy zbadano możliwości zastosowania sieci neuronowych do przewidywania wytrzymałości połączenia metal – ceramika w zależności od zastosowanych parametrów uprzedniej obróbki strumieniowo-ściernej. Na podstawie badań doświadczalnych opracowano zestaw 180 wzorców uczących a następnie uczono grupę 150 losowo wytypowanych sieci neuronowych, w celu doboru sieci o najlepszym dopasowaniu. Zaprojektowana sztuczna sieć neuronowa symuluje prawidłowo rzeczywistą zależność występującą podczas obróbki strumieniowo-ściernej i może być stosowana do określenia wytrzymałości połączenia metalu z ceramiką.

EN

The study investigated the possibility of using neural networks to predict the strength of the connection metal - ceramic depending upon the parameters of the prior blasting. On the basis of experiments developed a set of 180 patterns of learning and then were taught a group of 150 randomly selected neural network, for the selection of the network with the best match. Designed an artificial neural network simulates correctly the real dependence, produced during blasting and it can be used to determine the bond strength metal with ceramics.

11

Welding of Prosthetic Alloys

51%

Wojciechowska M. , Wołowiec-Korecka E. , Klimek L.

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tom Vol. 60, iss. 4

2703--2708

EN

This paper presents the techniques of joining metal denture elements, used in prosthetic dentistry: the traditional soldering technique with a gas burner and a new technique of welding with a laser beam; the aim of the study was to make a comparative assessment of the quality of the joints in view of the possibility of applying them in prosthetic structures. Fractographic examinations were conducted along with tensile strength and impact strength tests, and the quality of the joints was assessed compared to the solid metal. The experiments have shown that the metal elements used to make dentures, joined by the technique which employs a laser beam, have better strength properties than those achieved with a gas burner.

PL

W pracy przedstawiono stosowane w protetyce dentystycznej technologii zespalania metalowych elementów protetycznych: klasyczną technologię lutowania z użyciem palnika gazowego oraz nową technologię spawania z użyciem wiązki laserowej, a celem pracy było ocena porównawcza jakości otrzymanych połączeń w aspekcie zastosowania w konstrukcjach protetycznych. Przeprowadzono badania fraktograficzne oraz badania wytrzymałościowe na rozciąganie i udarność, oceniając jakość połączeń w stosunku do materiału litego. Badania wykazały, że elementy metalowe wykorzystywane w wykonawstwie uzupełnień protetycznych, połączone techniką z użyciem wiązki laserowej wykazują lepsze właściwości wytrzymałościowe niż te, które uzyskano po zastosowaniu klasycznej metody z wykorzystaniem palnika gazowego.

12

Welding of Prosthetic Alloys / Spawanie Stopów Protetycznych Typu Co-Cr

51%

Wojciechowska M. , Wołowiec-Korecka E. , Klimek L.

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nr 4

13

Use of optical microscopy for evaluation of tooth structure

38%

Banaszek K. , Sawicki J. , Wołowiec-Korecka E. , Gorzędowski J. , Danowska-Klonowska D. , Sokołowski J.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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tom Vol. 79, nr 1

31--40

EN

Purpose: There are many methods of examining tooth anatomy: some of them are applicable to the hard tissues, while others to the pulp and the root canal system. Every method has some advantages and disadvantages in terms of revealing specific anatomical or histological details of the tooth. The objective of the present work was to assess the use of macroscopic microscopy for evaluation of tooth anatomy and to compare the obtained images with those produced by the radiovisiographic method. Design/methodology/approach: The study involved 4 upper canines extracted for periodontal reasons from patients of different age and sex. Initially, radiological images were taken in the vestibular-lingual and lateral projections by the radiovisiographic method using a KODAK 2000 system with a KODAK 6100 sensor. Subsequently, the specimens were ground with sandpaper and consecutive dental cross-sections were captured at approximately 0.05 mm increments using a NIKON AZ100 multizoom microscope. Findings: The presented method, using side illumination and a digital capture device transferring the images to a computer, enables evaluation of tooth anatomy in terms of both shape and internal structure, and offers the dimensioning functionality. Practical implications: Optical microscopy is a cheap method of examining the hard tissues of the tooth, including restorative materials, and for evaluating the development of primary and secondary dentin, as well as dentin affected by bacterial infection. A microscope used in conjunction with good software provides many opportunities for easy examination and dimensioning of particular anatomical features of the tooth on consecutive planes. Originality/value: This is an honest methods review and analysis which are applied in modern prosthetics.

14

Low pressure carburizing in a large-chamber device for high-performance and precision thermal treatment of parts of mechanical gear

38%

Wołowiec-Korecka E. , Korecki M. , Klimek L. , Kula P. , Brewka A. , Buczek M.

Advances in Science and Technology. Research Journal

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2017

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tom Vol. 11, no 1

253--258

EN

This paper presents the findings of research of a short-pulse low pressure carburizing technology developed for a new large-chamber furnace for high-performance and precision thermal treatment of parts of mechanical gear. Sections of the article discuss the novel constructions of the device in which parts being carburized flow in a stream, as well as the low-pressure carburizing experiment. The method has been found to yield uniform, even and repeatable carburized layers on typical gear used in automotive industry.

15

The influence of quenching temperature on distortions during the individual quenching method

38%

Wołowiec-Korecka E. , Stachurski W. , Zgórniak P. , Korecki M. , Brewka A. , Byczkowska P.

Archives of Materials Science and Engineering

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2020

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tom Vol. 105, nr 2

80--85

EN

Purpose: In this paper, the impact of hardening temperature on the quenching distortions which occur during low-pressure carburizing with gas quenching - using the individual quenching method - was analysed. Design/methodology/approach: The reference elements were subjected to carburizing at 980°C, followed by gas quenching at temperatures of 860°C, 920°C and 980°C. The geometrical measurements of the elements were made before and after the chemical treatment and the size of the quenching distortions of their geometrical parameters was determined. Findings: It was demonstrated that a high temperature of quenching has an unfavourable effect on changes in cylindricity and roundness parameters but, at the same time, reduces the size of distortion of outer parameters. Low temperature quenching reduces quenching distortions of cylindricity and roundness parameters while increasing the distortion of outer dimensions. Research limitations/implications: Based on the research and analysis carried out in this work, it was found that the use of lower quenching temperature is justified in economic and quality terms. Practical implications: In the case of the aviation or automotive industry, very high quality of manufactured elements along with a simultaneous reduction of their production costs is extremely important. Maintaining the dimensions of the elements during heat treatment is extremely difficult. The tests allowed to determine the optimal hardening temperature, which brings with it acceptable deformations. Since it is easier to “repair” the outer geometrical dimensions (diameter, thickness), it seems that quenching from lower temperatures is a more favourable process. Originality/value: The conducted tests allowed to determine the most favourable conditions for hardening elements from the automotive industry, taking into account the occurring deformations and their subsequent processing

16

Wybrane aspekty regulowanego azotowania gazowego (RAG) oraz azotowania w obniżonym ciśnieniu (LPN)

38%

Michalski J. , Wołowiec-Korecka E. , Ratajski J. , Wach P. , Kucharska B. , Kula P. , Olik R.

Inżynieria Materiałowa

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2015

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tom Vol. 36, nr 6

444--448

PL

W artykule porównano efekty azotowania w procesie regulowanego azotowania gazowego (RAG), stosując atmosfery amoniaku rozcieńczane zdysocjowanym amoniakiem lub azotem, z procesem azotowania w warunkach obniżonego ciśnienia (LPN). Procesom azotowania poddano konstrukcyjne stale stopowe 41CrAlMo7 (38HMJ), 42CrMo4 (40HM), niskowęglowe stale niestopowe (stale 10 i 20) oraz żelazo Armco. Próbki poddano procesom regulowanego azotowania gazowego (RAG) w dwóch wariantach, RAG-1: NH3/NH3zd./N2 = 35/65/0 i RAG-2: NH3/NH3zd./N2 = 5/0/95 oraz zastosowano jeden wariant azotowania pod obniżonym ciśnieniem (LPN). Wspólnym parametrem charakteryzującym analizowane procesy był stopień dysocjacji amoniaku. Na podstawie przeprowadzonych badań wykazano, że w procesie RAG-1 można uzyskać monofazową warstwę azotków żelaza γ′ w dość szerokim zakresie stopni dysocjacji amoniaku. W procesach RAG-2 oraz LPN obszar trwałości fazy γ′ jest znacznie węższy i w związku z tym uzyskanie monofazowej warstwy azotków żelaza γ′ jest znacznie trudniejsze. W procesach LPN ograniczeniu obszaru trwałości fazy γ′ towarzyszy zwiększenie obszaru trwałości fazy α. Warunki kinetyczne w tych procesach sprzyjają wytwarzaniu warstw azotowanych bez przypowierzchniowej warstwy azotków żelaza. Z kolei w procesach azotowania w atmosferach azotujących uzyskanych z atmosfery dwuskładnikowej rozcieńczanej azotem (RAG-2) zwiększa się obszar trwałości fazy ε. Warunki kinetyczne w tych procesach sprzyjają wytwarzaniu warstw azotowanych z warstwami azotków będących mieszaniną faz γ′ i ε.

EN

In the article the effects of nitriding in the process of regulated gas nitriding (RAG) using ammonia atmosphere diluted by dissociated ammonia or by nitrogen with a nitriding process under low pressure (LPN) was compared. In studies 41CrAlMo7 (38HMJ), 42CrMo4 (40HM) alloy steels, low-carbon steels (steels 10 and 20) and Armco iron have been used. Nitriding of specimens was performed in regulated gas nitriding processes (RAG) in two variants, RAG-1: NH3/NH3zd./N2 = 35/65/0 and RAG-2: NH3/NH3zd./N2 = 5/0/95 and applied one variant of a nitriding under low pressure (LPN). Common parameter characterizing the processes was the degree of dissociation of ammonia. On the basis of studies have demonstrated that in the RAG-1 process can be obtained monophase layer of iron nitride γ′ in relatively wide range of dissociation of ammonia. In the RAG-2 and LPN processes γ′ phase stability region is much narrower and thus obtain a monophase layer of iron nitride γ′ is much more difficult. In the LPN processes reduce of area stability of the γ′ phase is accompanied by an increase in α phase stability region. Kinetic conditions in these processes conducive to the production of the nitrided layer without the subsurface layers of the nitrides iron. In turn, in the RAG-2 processes increase the area of ε phase stability. Kinetic conditions in these processes conducive to the production of nitrided layers with the subsurface layers of iron nitrides being a mixture of γ′ and ε phases.

17

System of single-piece flow case hardening for high volume production

32%

Wołowiec-Korecka E. , Korecki M. , Stachurski W. , Zgórniak P. , Sawicki J. , Brewka A. , Sut M. , Bazel M.

Archives of Materials Science and Engineering

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2016

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tom Vol. 79, nr 1

37--44

EN

Purpose: Purpose of this paper is development of single-piece flow system to precision thermal treatment of parts of mechanical gear using a short-pulse low-pressure carburising technology (developed for a new large-chamber furnace). Design/methodology/approach: Sections of the article discuss the novel constructions of the device in which parts being carburised flow in a stream, as well as the low-pressure carburising experiment. Findings: The method has been found proper carburised layers on typical gear used in automotive industry. Research limitations/implications: The short-pulse low-pressure carburising technology needs further investigation to fully understand its all mechanisms. Practical implications: The device resulting from the experiment can be a fully robotised part of a production line which can be included in a system of automatic control of a production process. Originality/value: The device resulting from the experiment is only known solution on the world.