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1

Analysis of the influence of the blanking clearance size to the burr development on the sheet of mild steel, brass and aluminium in blanking process

Kamarul Adnan A. A., Azinee S. N., Norsilawati N., Izzul K. A. M.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 111, nr 1

26--32

EN

Purpose: This research aims to analyse the influence of blanking clearance size on the burr development for mild steel sheet, brass and aluminium. The main reason for this research is estimating the burr size on blank parts. It is still significant since the quality of the products is determined by evaluating the amount of allowable burr in the parts. Design/methodology/approach: For the blanking process on the 3.00 mm thick sheets, various sizes of blanking clearance for a 20 mm diameter of the die opening are employed, as is the technique for obtaining the parts. Then the height of the burr on each product was measured using a micrometre and toolmaker microscope. The height of burr for each size of blanking clearance have been recorded and compared using a graph. Comparison made to identify which measure of blanking clearance and which type of material will produce a small size of burr. Findings: For mild steel, brass, and aluminium, blanking clearance 0.15 mm produced burr heights of 0.088 mm, 0.015 mm, and 0.024 mm, and blanking clearance 0.13 mm produced bur heights of 0.192 mm, 0.055 mm, and 0.046 mm, respectively. The brass had a lower burr height than mild steel and aluminium, according to the results. More significant blanking clearance (0.15 mm) produced a smaller size of burr compared to a smaller blanking clearance (0.13 mm). Practical implications: This study focuses on burr height rather than the wear of the punch and die cutting edge; burr height can affect punch and die sharpness. It also can guide practitioners in estimating blanking clearance and the burr height of mild steel, brass and aluminium. Originality/value: This paper demonstrates that the gap between the punch and die influences the burr height. The material strength also affects the burr height, with a high tensile strength resulting in a larger burr.

2

Investigation of the workability and surface roughness of thin brass wires in various dieless drawing technologies

Milenin Andrij, Wróbel Mirosław, Kustra Piotr

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 1

art. no. e10, 2022

EN

Possibilities of improving the workability of the CuZn37 brass thin wire in a diameter of 0.14–0.18 mm produced by the dieless drawing processes were explored. The workability was defined as the maximum final longitudinal strain of the wire up to its fracture, achievable in the dieless drawing process. Two technologies of dieless drawing were developed and their workability was compared. The first one is the classical one-pass process; the second, a multi-pass one. For both developed technologies, it was possible to obtain a good-quality product but more than two times higher workability has been demonstrated for the multi-pass technology. No evident effect of the deformation temperature from the window of technologically accepted parameters on the workability was found but an increase in the temperature significantly increased the roughness of the product surface. For the same deformation temperature, the roughness of the wire obtained from the multi-pass process appeared to be significantly lower than for the one of the classical one-pass technologies.

3

Ocena archeometalurgicznych stopów miedzi po wytworzeniu i po badaniach grawimetrycznych w roztworze imitującym kwaśną glebę

Brojanowska Agnieszka, Budniak Karolina, Miśta-Jakubowska Ewelina A., Moszczyńska Dorota

Ochrona przed Korozją

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2021

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nr 4

106--117

PL

Niniejsza praca mieści się na styku inżynierii materiałowej, korozjii archeologii eksperymentalnej. Do badań wybrano 1 mosiądz i 3 brązy. Próbki uzyskano poprzez wytop tyglowy mieszaniny składników stopowych i scharakteryzowano (morfologia powierzchni – SEM i skład chemiczny – EDS). Próbki umieszczono w roztworach wodnych symulujących natlenioną glebę o pH równym 3,6 i zawierającą jony Cl- i SO42- na okres prawie 1600 dni. Po wyjęciu próbek wykonano badania morfologii powierzchni (SEM), składu chemicznego (EDS) i fazowego (XRD) produktów korozji. Wykonano obliczenia szybkości korozji metodą grawimetryczną oraz zbadano pH roztworów po ekspozycji. Wykazano obecność odcynowania, jako mechanizmu korozji brązów archeometalurgicznych przy jednoczesnym braku stałych produktów korozji tego pierwiastka, co może doprowadzić do błędnej klasyfikacji rzeczywistych znalezisk archeologicznych. Wskazano również perspektywiczny charakter badań pH gleby w aspekcie oceny szybkości korozji artefaktów archeologicznych.

EN

The present work straddles the fields of materials engineering, corrosion and experimental archaeology. One brass and three bronze samples were selected for the study. The samples were obtained by crucible melting of a mixture of alloying elements and characterised (surface morphology - SEM and chemical composition - EDS). The samples were placed in aqueous solutions simulating oxygenated soil with a pH of 3.6 and containing Cl- and SO42- ions for almost 1600 days. After removing the samples, surface morphology (SEM), chemical composition (EDS) and phase composition (XRD) of the corrosion products were studied. Corrosion rate calculations were performed using the weight loss method and the pH of the solutions after exposure was investigated. Detinning as a corrosion mechanism for archaeometallurgical bronzes was demonstrated, while the absence of solid corrosion products of this element can lead to misclassification of actual archaeological finds. The prospective nature of soil pH studies in terms of assessing the corrosion rate of archaeological artefacts is also indicated.

4

Modified friction stir clinching-brazing of brass to AA5083 aluminum alloy using Zn interlayer

Li Jing, Tang Fei, Paidar Moslem

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 1

219--229

EN

The modified friction stir clinching (MFSC) of 5083 aluminum alloy to brass using pure Zn interlayer has been explored and elucidated for the first time. By that, the influence of the Zn interlayer thickness on the microstructure and the mechanical properties of the 5083/brass joint was investigated. The attained data have revealed that the intermetallic compound (IMC) layer thickness was mainly influenced by the Zn interlayer. The use of the Zn interlayer restrained the creation of brittle Al–Cu IMCs such as Al4Cu9 during the MFSC process and, in return, softer phases such as Cu4Zn, CuZn5, and CuZn were formed. It was also found that with increasing the thickness of the Zn interlayer from 50 to 100 µm, the thickness of the brazed zone increased and the tensile/shear strength of the spot welds significantly improved from 5250 to 8490 N (approximately 60% increment over the welded sample with 50-µm-thick Zn) which can be ascribed to supreme bonding and homogeneous brazing zone at the interface.

5

Microstructure and mechanical properties of CuZn-Al2O3 nanocomposites produced by friction stir processing

Heidarzadeh Akbar, Taghizadeh Babak, Mohammadzadeh Ahad

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 3

494--505

EN

For the first time, ceramic nano particles were incorporated into the brass alloy to produce surface nano composites by friction stir processing. For this aim, Al2O3 particles with an average diameter of 30 nm were inserted into a Cu-37Zn alloy at different tool rotational speeds of 450, 710, and 1120 rpm, multi passes, and a constant traverse speed of 100 mm/min. The microstructures of the processed materials were analyzed using optical and scanning electron microscopes equipped with an energy dispersive spectroscopy. In addition, tensile test was employed to evaluate the mechanical properties. The results showed that the optimum rotational speed was 710 rpm. At lower rotational speeds, Al2O3 particles were agglomerated. On the other hand, at higher rotational speeds, tool was damaged by severe wear. The effect of multi passes showed that one and two passes could not distribute the Al2O3 particles, uniformly. However, three passes resulted in a uniform distribution of the Al2O3 particles inside a bimodal grain structure composed of both 3–5 μm grains and ultra-fine grains (< 1 μm). By using multi-pass friction stir processing, a synergic increase in ultimate tensile strength and elongation was obtained. Moreover, three passes caused superior mechanical properties i.e. ultimate tensile strength of 430 MPa and elongation of 39%. The fracture behavior and strengthening mechanisms are also discussed in details.

6

The Influence of Abrasive Paste on the Effects of Vibratory Machining of Brass

Bańkowski D., Spadło S.

Archives of Foundry Engineering

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2019

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iss. 4

5--10

EN

The article presents the results of research on the finishing of M63 Z4 brass by vibratory machining. Brass alloy was used for the research due to the common use of ammunition elements, cartridge case and good cold forming properties on the construction. Until now, the authors have not met with the results of research to determine the impact of abrasive pastes in container processing. It was found that the additive for container abrasive treatment of abrasive paste causes larger mass losses and faster surface smoothing effects. The treatment was carried out in two stages: in the first stage, the workpieces were deburred and then polished. Considerations were given to the impact of mass of workpieces, machining time and its type on mass loss and changes in the geometric structure of the surface. The surface roughness of machining samples was measured with the Talysurf CCI Lite optical profiler. The suggestions for future research may be to carry out tests using abrasive pastes with a larger granulation of abrasive grains, and to carry out tests for longer processing times and to determine the time after which the parameters of SGP change is unnoticeable.

7

Integrated Analytical and Measurement System for the Evaluation of the Properties of Cast Metals and Alloys

Biernat S., Bydałek A. W.

Archives of Foundry Engineering

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2019

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iss. 1

13--18

EN

The article presents an integrated analytical and measurement system for evaluation of the properties of cast metals and alloys. The presented platform is an extension of the SLAG - PROP application with new modules, which allow to use information on metallurgical processes in an even more effective way, as well as to evaluate the finished product. In addition, the construction of a measuring station for the analysis of thermal processes taking place in a metal bath allows for precise observation of phenomena together with their appropriate interpretation. The article presents not only the cooling curves of certain copper alloys. The analysis also covered mechanical properties related to hardness, finished products depending on the mold in which the products were cast. In the literature one can find information about the mechanical properties of products in the improved state, usually after plastic or thermal treatment, omitting their properties obtained as a result of a naturally made casting. The article also presents the method of placing information in the database using a convenient graphical tool.

8

Analysis of the Impact of Modifiers on the Formation of Non-metallic Inclusions During Continuous Casting of CuZn39Pb2 Brass

Bydałek A. W., Kula A., Błaż L., Najman K.

Archives of Foundry Engineering

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2019

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iss. 3

21--26

EN

In this paper results of microstructural observations for series of CuZn39Pb2 alloys produced from qualified scraps are presented. The individual alloy melts were differentiated in terms of thermal parameters of continuous casting as well as refining methods and modifications. Structural observations performed by SEM and TEM revealed formation of different types of intermetallic phases including “hard particles”. EDS results show that “hard particles” are enrich in silicon, phosphorus, iron, chromium and nickel elements. Additionally, formation of Al-Fe-Si and Al-Cr in alloy melts was observed as well. It was found that quantity and morphology of intermetallic phases strongly depends upon the chemical composition of raw materials, process parameters, modifiers and refining procedure applied during casting. It was observed that refining process results in very effective refinement of intermetallic phases, whereas modifiers, particularly carbon-based, results in formation of large particles in the microstructure.

9

Relief of residual stress in Al2O3/Nb joints brazed with Ag-Cu-Ti/Cu/Ag-Cu-Ti composite interlayer

Zhao Yating, Wang Ying, Yang Zhenwen, Wang Dongpo

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 1

1--10

EN

Ag-Cu-Ti/Cu/Ag-Cu-Ti composite interlayer was successfully designed to braze Al2O3 ceramic and Nb. The effect of the addition of Cu interlayer with various thicknesses on the microstructure, residual stress and mechanical properties of the brazed joints was investigated by finite element modeling (FEM) computation combined with experimental verification. The results showed that the layered Ag-Cu-Ag solid solution structure formed in the Al2O3/Nb brazed joints when the composite interlayer was used. Moreover, the thickness of TiO + Ti3Cu3O reaction layers adjacent to the Al2O3 ceramic substrate did not change obviously regardless of the Cu foil thickness. The maximum residual stress in the whole brazed joint always appeared in the Al2O3 ceramic substrate nearby the interlayer, but it was reduced from 384 MPa to 119 MPa when a 150 μm thick Cu foil was added. The variation of calculated residual stresses as a function of Cu foil thickness, which was verified by X-ray measurement, exhibited a consistent with Al2O3 ceramic strain energy. Thus, the calculation of Al2O3 ceramic strain energy could be a good criterion to evaluate the joint shear strength because the fracture occurred in the Al2O3 ceramic. The reduction of detrimental residual stress was primarily attributed to the increased plastic strain energy of Cu interlayer. The FEM and experiment results indicated that the ability of plastic deformation of the interlayer played a key role in determining the residual stress in the brazed joint, providing a method for improving the bonding properties of ceramic and metal.

10

Microstructure and mechanical properties of Ti2AlNb alloy and C/C composite joints brazed with Ag–Cu–Zn and Ag–Cu–Zn/Cu/Ag–Cu–Ti filler metals

Hao Zhitao, Wang Dongpo, Yang Zhenwen, Wang Ying

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 4

1083--1094

EN

C/C composite was successfully joined to Ti2AlNb alloy with inactive filler metal, Ag–Cu–Zn filler. In addition, a designed composite interlayer, Ag–Cu–Zn/Cu/Ag–Cu–Ti, was used to improve the properties of brazed joints. AlCu2Ti compound blocks were formed in brazing seam and the double reaction layers adjacent to C/C composite were AlCu2Ti and TiC when Ag–Cu–Zn filler was used to join C/C composite and Ti2AlNb. With the increase of brazing temperature and time, the amount of AlCu2Ti compound blocks increased and tended to accumulate together nearby the C/C composite, the double reaction layers thickened as well. In order to avoid the serious accumulation of brittle AlCu2Ti compound nearby C/C com-posite, Cu foil was added between the Ag–Cu–Zn filler and Ti2AlNb. Soft Cu but not brittle AlCu2Ti existed nearby the C/C composite with the addition of Cu foil, which is beneficial for the relief of residual stress near the C/C composite, and the shear strength of joint improved obviously. With the barrier of Cu foil, the thickness of reaction layers adjacent to C/C composite could be controlled easily by the addition of Ag–Cu–Ti foil. Correspondingly, the shear strength of this joint reached at 28 MPa, which was close to that of C/C itself.

11

Elektroplastyczne skręcanie oscylacyjne mosiądzu CuZn30

Zimniak Z., Weiler W., Zwierzchowski M., Jaśkiewicz K.

Przegląd Mechaniczny

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2018

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nr 2

45--48

PL

W artykule przedstawiono wyniki badań małocyklowego skręcania prowadzone z zastosowaniem wysokoprądowych impulsów elektrycznych. Zbadano wpływ zachowania się mosiądzu CuZn30 na równoczesne cykliczne skręcanie w powiązaniu z efektem elektroplastycznym. Do badań próby skręcania wykorzystano plastometr pozwalający na realizację złożonych dróg odkształcenia. Dla założonej stałej amplitudy odkształcenia oraz zmiennych parametrów prądowych wykazano możliwości modyfikowania naprężenia uplastyczniającego oraz odkształcenia całkowitego próbki. Wykonane badania mikrostrukturalne pokazują również, że w zależności od przyjętych parametrów prądowych istnieje możliwość zwiększania lub zmniejszania wielkości ziaren materiału.

EN

In this paper, a pulsed electric current is applied to specimen simultaneously with cyclic torsion. The effects of cyclic torsion and electroplasticity on behavior of 70/30 brass have been investigated. Symmetrical minor cycling torsion was conducted in a plastometer for complex strain paths. The decrease of flow stress and plastic strain under minor cyclic torsion stress is obtained for applied fixed strain amplitude and at different electric current pulsed. Observations of microstructure revealed the occurrence of material grain size was refined or magnified.

12

Badania podatności do przeróbki plastycznej niskoołowiowych mosiądzów armaturowych

Malec W., Juszczyk B., Wierzbicki Ł., Cwolek B., Kulasa J., Kalabis J., Borowski J., Staniek R., Meller G., Lehmann M.

Hutnik, Wiadomości Hutnicze

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2018

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Vol. 85, nr 9

292--296

PL

W pracy przedstawiono wyniki prób ściskania mosiądzów o zmodyfikowanym składzie chemicznym przeznaczonych na odkuwki elementów armatury. Badano wpływ składu chemicznego oraz temperatury ściskania na zmiany naprężenia uplastyczniającego. Analizie poddano również zmiany mikrostruktury wywołane odkształceniem plastycznym. Stwierdzono, że w zakresie temperatury 650ºC-750ºC wartość naprężenia uplastyczniającego dla stopów normowanych CW617N i CW612N jest znacznie wyższa niż dla stopów doświadczalnych.

EN

This paper presents the results compression tests of brass with modified chemical composition designed for forged of fittings. The effect of the chemical composition and compression temperature on the changes of flow stress was investigated. The changes of microstructure due to plastic deformation were also analyzed. It was found that in the temperature range 650ºC-750ºC value of flow stress for normalized alloys is much higher than for experimental alloys.

13

Determination of the Technological Parameters Process for Continuously Cast Brass Ingot

Bydałek A. W., Kwaśniewski P., Schlafka P., Wołczyński W., Najman K.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

9--14

EN

This article discusses issues related to continuous casting of brass. The tested material was CuZn39Pb2 brass with the use of continuous casting and different parameters of the process. The position consists of a melting furnace with a graphite refining pot of about 4000 cm3 chuting capacity, a graphite crystallizer of 9,5 mm nominal diameter, a primary and secondary cooling system and an extracting system as well. The analysis was carried out in terms of technological parameters of the process and type of charge. Highlighted: feedrate ingot, number of stops, and technological temperatures. The surface quality of the obtained ingots and the structure were analyzed. The most favorable conditions were indicated and technological recommendations indicated. They have been distinguished for ingots for plasticity and other technologies. Favorable casting conditions are low feed and low temperature. Due to the presence of impurities coming from the charge it is disadvantageous to have Ni greater than 0.053% by mass, and Fe more than 0.075% by mass. It is recommended to maintain a high zinc content in the melt which is associated with non-overheating of the metal during casting and earlier melting.

14

Stress corrosion cracking of leaded brass with various aluminium and tin content

Kondracki M.

Ochrona przed Korozją

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2017

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nr 10

344--347

EN

The paper presents studies on stress corrosion of cast leaded copper-zinc alloys containing aluminium and tin additions. The analysis of alloys susceptibility to this process was conducted on the base of the modified ammonia test which consisted of impact test results comparison for studied alloys after different time of exposure. Additionally, the structure was examined using electron and optical microscopy methods. Results of the studies have shown different resistance of studied alloys , depending on the chemical composition to the process of stress corrosion cracking.

PL

Artykuł prezentuje badania korozji naprężeniowej odlewniczych mosiądzów ołowiowych zawierających dodatki aluminium i cyny. Analiza podatności stopów na korozję naprężeniową została przeprowadzona przy pomocy zmodyfikowanej próby amoniakalnej, obejmującej badania udarności próbek w funkcji czasu ekspozycji. Do badań struktury stopów wykorzystano metody mikroskopii świetlnej i elektronowej. Wyniki badań pokazały zmienną odporność na korozję naprężeniową stopów zależnie od ich składu chemicznego.

15

Repairs of Damaged Castings Made of Graphitic Cast Iron by Means of Brazing

Mician M., Konar R.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 3

91--96

EN

The article summarizes the theoretical knowledge from the field of brazing of graphitic cast iron, especially by means of conventional flame brazing using a filler metal based on CuZn (CuZn40SnSi – brass alloy). The experimental part of the thesis presents the results of performance assessment of brazed joints on other than CuZn basis using silicone (CuSi3Mn1) or aluminium bronze (CuAl10Fe). TIG electrical arc was used as a source of heat to melt these filler materials. The results show satisfactory brazed joints with a CuAl10Fe filler metal, while pre-heating is not necessary, which favours this method greatly while repairing sizeable castings. The technological procedure recommends the use of AC current with an increased frequency and a modified balance between positive and negative electric arc polarity to focus the heat on a filler metal without melting the base material. The suitability of the joint is evaluated on the basis of visual inspection, mechanic and metallographic testing.

16

Badania nad opracowaniem nowych geometrii nośno-przewodzącego osprzętu tramwajowej sieci trakcyjnej

Kisielewicz B., Kordaszewski S., Kawecki A., Sieja-Smaga E., Zasadzińska M., Jurkiewicz B., Grzebinoga J., Franczak K.

Rudy i Metale Nieżelazne Recykling

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2016

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R. 61, nr 11

484--489

PL

Wzrost zapotrzebowania na przesyłanq energią wskutek ciągłego postępu technologicznego, wymusza konieczność poszukiwania nowych mate¬riałów oraz innowacyjnych rozwiązań geometrycznych osprzętu sieci trakcyjnej, pozwalających na zmniejszenie strat przesyłanej energii. W związku z tym, w ramach projektu INNOJECH III, na Wydziale Metali Nieżelaznych Akademii Górniczo-Hutniczej im. Stanisława Staszica, we współpracy z firmą KUCA, podjęto badania, których celem było opracowanie oraz wdrożenie nowego typu osprzętu nośno-przewodzącego tram¬wajowej sieci trakcyjnej. W artykule przedstawiono szereg wyników przeprowadzonych symulacji numerycznych, bazujących na metodzie ele¬mentów skończonych, którym poddano obecnie stosowane elementy osprzętu sieci trakcyjnej. Analiza ta pozwoliła na uzyskanie parametrów wytężeniowych osprzętu, których badanie na drodze doświadczalnej jest bardzo trudne, kosztowne lub nawet niemożliwe. W oparciu o pozyskaną wiedzę, podjęto prace badawcze zmierzające do opracowania nowego typu geometrii osprzętu nośno-przewodzącego, które następnie poddano analizom numerycznym, celem zbadania ich poprawności konstrukcyjnej pod kątem jednorodności rozkładu naprężenia i odkształcenia sprężystego w warunkach ich rzeczywistej pracy, przy uwzględnieniu różnych wariantów materiałowych. Przedstawione w artykule geometrie są wstępnymi koncepcjami, które w toku prowadzonych prac były modyfikowane oraz optymalizowane. Dodatkową weryfikację poprawności konstrukcyjnej opracowanych geometrii, stanowiło prototypowanie metodą druku 3D. Metoda ta pozwala na ocenę wizualną przygotowanych kształtów oraz fi¬zyczną weryfikację kompatybilności części składowych elementu. Koncepcje nowoopracowanych rozwiązań konstrukcyjnych nośno-przewodzące¬go osprzętu wykraczają poza ograniczenia wynikające ze stosowanej technologii klasycznego odlewania do form piaskowych i kokilii, co wymusza zastosowanie nowoczesnej, zintegrowanej metody odlewania, kucia matrycowego i wykańczającej obróbki cieplnej.

EN

Growth in demand for electricity distribution due to continuous technological progress makes it necessary to bok for a new materials and innovative solutions of overhead tram equipment allowing to reduce the transmitted energy loss. Therefore within the national INNOTECH III project realized at the Department of Non-Ferrous Meta/s ofAGH Un/i/ers/ty of Science and Technology in collaboration with KUCA company, research studies were ini-tiated to develop and implement a new type ofoverhead tramway equipment. As a part of this art/cle selected research results of numerical simula-tions were showedbasedon thefinite element method for currently usedelements ofthe overhead tramway traction. This analysis allowed to obtain stress andstrain characteristics. Based on the obtained knowledge the studies research were carried outin order to develop a new type ofoverhead tram equipment Created concepts subjected to numerical analysis allowed to examine the correctness of the design in terms of homogeneity of stress and elastic deformation distribution with regards to the real operating conditions and use of different materials. Geometries presented in the article arę preliminary concepts which were modified and optimized during the research. Additiona/ verification ofthe correctness of des/gned geom-etries were done with the use of3D prototyping. This method allows for visual assessment andphysical verifkation of the components compatib/lity. Concepts of newly designed supporting-conducting elements arę beyond the limitations of traditional production technology (sand casting and permanent mould casting) which forces to use modern continuous casting technology integrated with die forging and finał heat treatment of the obtained elements.

17

Wpływ geometrii narzędzia na rozdrobnienie ziarna stopu CuZn37 w procesie powtarzalnej obróbki plastycznej

Rusz S., Salajka M., Hilser O., Dutkiewicz J., Boruta J., Švec J.

Obróbka Plastyczna Metali

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2016

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T. 27, nr 4

301--314

EN

Development of technologies for the production of very fine-grained materials is currently very intensively accelerated. On VSB -Technical University of Ostrava developed a method that uses the principle of severe plastic deformation to refine the structure and enhance mechanical properties of sheet metal strips. The greatest importance in practice represents an increase in proof stress and tensile stress of sheet metal strips. Dual Rolls Equal Channel Extrusion (DRECE) method is a newly developed method. Severe plastic deformation results in a high degree of the material reformation. The method can be used to produce metallic materials with a very fine grain structure (hereinafter referred to as ultrafine grain structure). The forming process is based on extrusion technology with zero removal of the sheet strip thickness with the ultimate aim of achieving a high degree of deformation in the formed material, resulting in a significant improvement of mechanical properties in the input material. The paper analyses the effects of the values of angles of the newly developed forming tools on the achievement of mechanical properties in selected materials Cu and brass in the SPD process. The following types materials were verified experimentally – strip sheet with dimensions 58 (width) x 2 (thickness) x 1000 (length) mm. The paper also evaluates the influence of severe plastic deformation (SPD) on strengthening these materials at different values of the angle in the forming tool. The influence of new geometries of forming tools for improving mechanical properties has been unequivocally demonstrated.

PL

Rozwój technologii produkcji materiałów ultra drobnoziarnistych jest obecnie bardzo intensywnie przyspieszany. Na VŠB – Uniwersytecie Technicznym w Ostravie opracowano metodę, która wykorzystuje zasadę powtarzalnej obróbki plastycznej w celu rozdrobnienia struktury i poprawy właściwości mechanicznych taśm blachy metalowej. Największe praktyczne znaczenie ma wzrost umownej granicy plastyczności oraz granicy wytrzymałości taśm blachy metalowej. Nowo opracowaną metodę stanowi wyciskanie równokanałowe podwójnymi rolkami (DRECE). Powtarzalna obróbka plastyczna (SPD) skutkuje wysokim stopniem przetworzenia materiału. Metodę tę można stosować do produkcji materiałów metalicznych o bardzo drobnoziarnistej strukturze (dalej zwanej strukturą ultradrobnoziarnistą). Proces kształtowania jest oparty na technologii wyciskania z zerową redukcją grubości taśmy blachy z końcowym celem osiągnięcia wysokiego stopnia odkształcenia w formowanym materiale, co skutkuje znaczną poprawą własności mechanicznych materiału wejściowego. W niniejszym artykule przeanalizowano wpływ wartości kątów nowo opracowanych narzędzi kształtujących na osiągnięcie własności mechanicznych w wybranym materiale, mianowicie mosiądzu, w procesie SPD. Sprawdzono doświadczalnie następujące rodzaje materiałów: taśma blachy o wymiarach: 58 mm (szerokość) x 1000 mm (długość) x 2 mm (grubość). W pracy oceniono również wpływ powtarzalnej obróbki plastycznej (SPD) na umocnienie tych materiałów przy różnych wartościach kąta narzędzia kształtującego. Wykazano jednoznacznie wpływ nowych geometrii narzędzi kształtujących na poprawę własności mechanicznych.

18

Nieniszczące badania metodą prądów wirowych w odniesieniu do pomiarów twardości HV jako komplementarna kontrola jakości wyrobów mosiężnych

Jończyk S., Samborski T., Włodarczyk S.

Inżynieria Powierzchni

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2016

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nr 1

18--23

PL

W pracy przedstawiono wyniki pomiarów metodą prądów wirowych w korelacji z rozkładem twardości HV5 w odniesieniu do wyrobów mosiężnych. Celem badań był dobór techniki nieniszczącej kontroli jakości produkcji weryfikującej we wszystkich wyrobach żądaną wartość twardości powyżej określonej granicy, a także eliminującej wyroby z lokalnymi wadami. Zastosowano pomiary porównawczą metodą prądów wirowych. Wykonana do tych badań sonda przelotowa, uśredniająca sygnały od wad na obwodzie, umożliwiła eliminację detali różniących się od wzorca. Badania laboratoryjne, wykonane na zbiorze 1000 szt. tulei, wykazały korelację wyników pomiarów twardości i oznaczeń prądami wirowymi. Selekcja wyrobów wadliwych w zbiorze 25 000 szt. tulei, przeprowadzona w warunkach eksploatacyjnych, potwierdziła właściwy dobór wzorców i prawidłowość przyjętych rozwiązań pomiarowych. Uzyskano zmniejszenie liczby wadliwych wyrobów z 40 do 4%. Metoda prądów wirowych okazała się przydatna do nieniszczącej, szybkiej kontroli jakości wszystkich wyrobów mosiężnych w warunkach produkcyjnych.

EN

This paper presents the results of the measurements taken by means of the eddy current method in relation to the HV5 hardness distribution with reference to brass products. The aim of these test s was the selection of a non-destructive quality control technique of production which enables the verification of all of the products in terms of the desired hardness value and the elimination of the products with defects. The measurements which were used were taken by the comparative eddy current method. The encircling coil which was made for these tests, and which averages the signals from defects on the circuit. Allowed to eliminate the elements which were different from the reference standard. Laboratory tests performed on the set of 1.000 pieces of sleeves showed a correlation between the hardness measurement results and the indications by the eddy current testing device. The elimination of the defective products in the set of 25.000 pieces of sleeves, carried out under the exploitation conditions, confirmed the proper choice of reference standard and the correctness of the accepted measurement solutions. The decrease of the number of defective products from 40% to 4% was gained. The eddy current method has proved to be useful for the non-destructive rapid quality control of all brass products under production conditions.

19

Idea i konstrukcja modeli do badań wpływu korozji na jakość wody

Laskowski T., Nawrocki J.

Instal

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2016

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nr 9

63--66

PL

Korozja w sieci dystrybucyjnej może pogarszać jakość wody. Dotychczas badania związane z korozją sieci prowadzono na stosunkowo długich odcinkach przewodów albo na tzw. kuponach materiału, z którego zbudowana jest sieć. Nasz pomysł dotyczy badania wpływu korozji na jakość wody przy pomocy modeli bazujących na opiłkach metali. Model pozwala zmniejszyć kubaturę konieczną do badań, ponieważ niewielka ilość opiłków posiada powierzchnię równoważną długim odcinkom rur. Model podzielony jest na sektory, co pozwala sprawdzać wpływ kilku parametrów wody na zmiany jakości wody pod wpływem zjawisk korozyjnych. Wykazaliśmy doświadczalnie, że zmiany jakości wody następują głównie podczas stagnacji wody. Elastyczność proponowanego modelu pokazano wykorzystując różne materiały stosowane w sieciach dystrybucyjnych (żeliwo, miedź, mosiądz) i badając wpływ różnych parametrów wody na korozję i następujące po tym zmiany jakości wody. Dla żeliwa i miedzi przeprowadzono eksperymenty porównawcze na rzeczywistych rurach.

EN

Corrosion in a distribution network may substantially decrease water quality. So far the investigations of corrosion phenomena were carried out on some relatively long fragments of pipes or with application of coupons of construction materials. The idea presented here consists of using a metal filings based models for determination of corrosion impact on water quality. The model allows decreasing the space requirements for such research compared to application of fragments of pipes. The model is divided into several sectors what allows observing the impact of several parameters of water on its quality. The experiments show that the changes of water quality are observed mainly during periods of stagnations. The flexibility of the model is shown by using it for different materials used in distribution systems (such as cast iron, copper and brass) as well as for different water parameters. The results of the experiments with cast iron and copper were confirmed on pilot station with the real pipes made of the materials.

20

Structural Zones in Large Static Ingot. Forecasts for Continuously Cast Brass Ingot

Wołczyński W., Lipnicki Z., Bydałek A. W., Ivanova A. A.

Archives of Foundry Engineering

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2016

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Vol. 16, iss. 3

141--146

EN

Some metallographic studies performed on the basis of the massive forging steel static ingot, on its cross-section, allowed to reveal the following morphological zones: a/ columnar grains (treated as the austenite single crystals), b/ columnar into equiaxed grains transformation, c/ equiaxed grains at the ingot axis. These zones are reproduced theoretically by the numerical simulation. The simulation was based on the calculation of both temperature field in the solidifying large steel ingot and thermal gradient field obtained for the same boundary conditions. The detailed analysis of the velocity of the liquidus isotherm movement shows that the zone of columnar grains begins to disappear at the first point of inflection and the equiaxed grains are formed exclusively at the second point of inflection of the analyzed curve. In the case of the continuously cast brass ingots three different morphologies are revealed: a/ columnar structure, b/ columnar and equiaxed structure with the CET, and c/ columnar structure with the single crystal formation at the ingot axis. Some forecasts of the temperature field are proposed for these three revealed morphologies. An analysis / forecast of the behavior of the operating point in the mold is delivered for the continuously cast ingot. A characteristic delay between some points of breakage of the temperature profile recorded at the operating point and analogous phenomena in the solidifying alloy is postulated.