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1

Qualitative Research of AZ31 Magnesium Alloy Aircraft Brackets Produced by a New Forging Method

Dziubińska A., Gontarz A., Dziedzic K.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2B

1003--1008

EN

The paper reports a selection of numerical and experimental results of a new closed-die forging method for producing AZ31 magnesium alloy aircraft brackets with one rib. The numerical modelling of the new forming process was performed by the finite element method.The distributions of stresses, strains, temperature and forces were examined. The numerical results confirmed that the forgings produced by the new forming method are correct. For this reason, the new forming process was verified experimentally. The experimental results showed good agreement with the numerical results. The produced forgings of AZ31 magnesium alloy aircraft brackets with one rib were then subjected to qualitative tests.

2

A New Method for Producing Finned Heat Sinks for Electronic Applications

Dziubińska A., Gontarz A.

Przegląd Elektrotechniczny

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2014

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R. 90, nr 4

74--77

EN

The paper presents new methods for forming heat sinks by forging. In the first part of the paper, an overview of methods for producing heat sinks is given, and the most common industrial applications of heat sinks are presented. The paper then examines the problem of producing such products by forging with the use of a three-slide forging press. The paper also presents the assumptions underlying the method for producing heat sinks which was developed at Lublin University of Technology and claimed under Patent Application No. P. 404274 of June 10, 2013.

PL

W opracowaniu przedstawiono nowe możliwości kształtowania radiatorów metodą kucia. W pierwszej części opracowania przeprowadzono przegląd metod wytwarzania radiatorów oraz podano ich najczęstsze zastosowanie w przemyśle. W dalszej części przedstawiono analizę stanu zagadnienia w zakresie możliwości kucia tego typu wyrobów przy wykorzystaniu trójsuwakowej prasy kuźniczej. W niniejszym artykule przedstawiono założenia metody wytwarzania radiatorów opracowanej w Politechniki Lubelskiej zawartej w zgłoszeniu patentowym nr P. 404274 z dnia 10.06.2013 r.

3

Forming of external steps of shafts in three slide forging press

Gontarz A., Myszak R.

Archives of Metallurgy and Materials

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2010

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Vol. 55, iss. 3

689-694

EN

This paper presents the results of research concerning forming of external shafts steps in three-slide forging press (TSFP). This hydraulic press is characterized by three slides – one vertical and two horizontal. Such a design allows for economical forming of forgings of stepped axles and shafts by means of upsetting methods. The authors did the research aiming at determining limiting conditions of billet diameter enlarging in cylindrical impression. In order to do these research, tools set with changeable elements constituting the impression was designed and made. Such a design of tools allowed for determining of the impression length and diameter influence on the upsetting process. The minimum length of the impression of a given diameter was determined by changes of the impression diameter D within the range of D = (1.25-1.6)d (where: d – billet diameter). On the basis of the obtained results, guidelines for the designing of forming process of external shafts steps in TSFP were worked out. Nomograms, on the basis of which the number of operations and geometrical parameters of the used tools can be determined, were made. These guidelines were applied for designing of forging processes of external steps with different diameter and lengths. The conducted experimental verification confirmed the rightness of the assumptions – forgings of the assumed quality were obtained.

PL

W opracowaniu przedstawiono wyniki badan dotyczace kształtowania skrajnych stopni wałów w trójsuwakowej prasie kuźniczej (TPK). Wymieniona prasa o napędzie hydraulicznym charakteryzuje się trzema ruchomymi suwakami – jednym pionowym i dwoma poziomymi. Taka budowa umożliwia ekonomiczne kształtowanie odkuwek typu stopniowane wały i osie metodami spęczania. Autorzy podjęli badania zmierzające do określenia warunków granicznych powiększania średnicy wsadu w wykroju walcowym. W tym celu zaprojektowano i wykonano zespół narzedziowy posiadajacy wymienne elementy tworzace wykrój. Taka konstrukcja narzedzi pozwoliła okreslic wpływ długosci i srednicy wykroju na przebieg procesu spęczania. Zmieniajac średnice wykroju D w granicach D = (1,25-1,6)d (gdzie: d – średnica wsadu) określono minimalna długość wykroju dla danej srednicy, przy której proces kształtowania przebiega prawidłowo. Na podstawie uzyskanych wyników opracowano wytyczne do projektowania procesu kształtowania skrajnych stopni wałów w TPK. Sporzadzono nomogramy, na podstawie których oraz w oparciu o wymiary kształtowanego stopnia mozna wyznaczyć ilość zabiegów oraz parametry geometryczne stosowanych narzędzi. Wytyczne te zastosowano do projektowania procesów kucia skrajnych stopni o róznych średnicach i długościach. Przeprowadzona weryfikacja doswiadczalna potwierdziła prawidłowosc przyjetych założeń – otrzymano odkuwki o założonej jakości.

4

The new forging process of a wheel hub drop forging

Gontarz A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

363--366

EN

Purpose: The main purpose of the research was working out a new flashless forming process of wheel hub forging in three-slide forging press (TSFP). It was assumed that the new process would be more effective than the forging processes applied in typical forging machines. Design/methodology/approach: The designing of the new process was based on the simulation by finite element method with the assumption of 3D state of strain. Calculations were made mainly for the analysis of the material flow kinematics and the process loads parameters. Experimental research were also made determining the dependency of clamping load in the function of forming load. On the basis of the analysis, the forming process of a wheel hub drop forging on the TSFP was worked out. Findings: The results of research confirmed the possibility of flashless forming process of wheel hub forging in TSFP with axial cavities. The main parameters limiting the forming processes of wheel hub forgings are: permissible upsetting ratio and reciprocal relation of forming and clamping forces. Research limitations/implications: The further research within the range of determining force parameters for different types of material and schemata of forming in TSFP were considered as purposeful. The works dealing with analysis of forming processes of different types of products in order to classify drop forgings possible to form in this press will be examined. Practical implications: The comparison of the new forming process with the forging process on hammer showed majority of advantages which include: decrease of time and energy, decrease of drop forging weight and machining, decrease of material consumption. Originality/value: The new process of wheel hub forging forming with axial cavities was worked out. The parameters important during designing of forming processes in TSFP were provided. The relations between forces of forming tools were also determined.

5

Research of upsetting ratio in forming processes on a three - slides forging press

Weroński W. S., Gontarz A., Pater Z.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

409--412

EN

Purpose: The purpose of the presented in this work research was determining the limiting conditions of upsetting in three-slide forging press (TSFP). The free upsetting process and upsetting process in cylindrical impression were analyzed. Design/methodology/approach: The assumed purpose was confirmed in experimental research. For the case of upsetting in cylindrical impression, the research of limiting upsetting coefficients were made for different diameters and impression lengths. Findings: The obtained results showed large variety of limiting upsetting ratio depending on the analyzed impression geometrical parameters. It was stated, that there are 3 phenomena limiting the upsetting process in the die. The main phenomenon is the bar upsetting outside the impression. The upsetting processes in the impression are limited also by bar buckling outside the impression and overlapping inside the impression. Research limitations/implications: The results of research allowed for stating that, besides the process geometrical parameters, friction conditions and type of the formed material influenced the limiting upsetting coefficients in the cylindrical impression. It is purposeful to make the further research determining quantitative and qualitative dependencies between these factors. Practical implications: The obtained results are the basis for designing of forming processes in TSFP in which the upsetting dominates. Especially it considers the elongated forgings and elongated preforms with thickenings. Originality/value: The influence of the impression geometrical parameters on the limiting upsetting coefficients for the case of upsetting in cylindrical impression in TSFP has been analyzed in details. The dependencies, which should be used during designing of upsetting processes in TSFP were determined.