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Copyright © 2007 editura Ştiinţifică F.M.R.-Bucharest, Romania

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Manager Scientific Publishing House F.M.R.:

eng. Florentina Brânduşa Scorţea

 

Assistant-secretary Editura Ştiinţifică F.M.R.

ANCA ION

 Metalurgia

INTERNATIONAL

(magazine set-up in 1995)

 

English version, published by

romanian metallurgical foundation

 

Honorary president of  scientific publishing house f.m.r.

Dr. ec. Lepădatu v. gheorghe

 
                       

                                                        vol. XII

                                                                  (2007)

                                                                  no.8

 

romanian metallurgical foundation

Scientific publishing house

Honourary Staff

(in alphabetical order)

 

bensabra    hakim    (algeria),    BORDEA MARIUS, chabour    salem    (algeria),     gencang    yang    (china), 

  R.  S.     HOUK     (S.U.A.), I. IMRIŠ  (TECHNICAL  UNIVERSITY  OF  KOŠICE,  SLOVAK  REPUBLIC),      puşici miho (Slovenia), roşescu     gheorghe  (grecia),     roxana  ruxandra     (california),   w.m. nicola (tri. state university angola, indiana, s.u.a.), xianqing you (china)

 

 

romanian metallurgical foundation

Scientific publishing house

 

editorial  board :

 

Prof. colan horia Ph. D., member of Romanian Academy of Technical    Sciences

Prof. Coşmeleaţă georgeta Ph. D.

Prof. Elena drăgulănescu Ph. D., Catedra GDGI,  Aerospatial Engineering Faculty, Bucharest Politechnical University, Romania

Prof. Dumitrescu Constantin Ph. D., deputy member of Romanian Academy of Technical Science

Prof. French David Ph. D., CSIRO Energy Technology, Australia

Prof. Găluşcă Dan-Gelu Ph. D.

Prof. Mihaela Grigore Ph. D., University of New South Wales, Sydney, Australia

Prof. Lawson Cristopher Ph. D., Copenhague Technical Institute, Denmark

Dr. Ec. Lepădatu V.Gheorghe, Demetrius Cantemir Christian

University, Bucharest, Romania

Prof. Nicolae Avram Ph. D.

Prof. Maria Nicolae Ph. D.

Prof. doc. Oprea Florea Ph. D., member of Romanian Academy of Technical Sciences

Prof. Veena Sahajwalla Ph. D., University of New South Wales, Sydney, Australia

Prof. Sakurovs Richard Ph. D., CSIRO Energy Technology, Australia

Prof. Salvo Luc Ph. D., Grenoble National Politechnical Institute, France

Prof. Saiter Jean-Marc Ph. D., Rouen University, France

Prof. Simiti Ioan Vida Ph. D.

Prof. Sofroni Laurenţie Ph. D., member of Romanian Academy of Technical Sciences

Prof.  Şaban Rami Ph. D., Dean of  Materials Science Faculty, Bucharest Politechnical University

Prof. ŞTEFĂNESCU DORU Ph. D, Ohio State University   Columbus, S.U.A.

Prof.VASIU Teodor Ph. D., Faculty of „Engineering” in Hunedoara, Romania

 

advisory board :

 

Prof.  bejan Mircea Ph. D

Prof.  cănănău nicolae  Ph. D

Prof.  hepuţ teodor Ph. D

Prof.  miloşan ioan Ph. D

Prof.  Doina Răducanu Ph. D

Prof.  samoilă Corneliu  Ph. D

prof. semenescu augustin ph. d

Prof.  SOFONEA GALAgTION Ph. D

Prof.  VARGA BELA Ph. D

 

Managing Director:

Editor-in-chief:

Professor Scorţea Costin Ph. D.

 

Contents

 

Issn 1582 – 2214

 

VARGA Bela, Bedő Tibor,  Cozma R., Bobancu S.: Wear strenght of Al-Si alloys

 fused with low-melting elements ……… 5

 

GEAMĂN  Virgil: High pressure processing

 of food ……………………………….… 10

 

Simona BOICIUC, Sanda LEVCOVICI, LEVCOVICI  Dan T.: Structural modifications

 in laser cladding layers heating up at

different temperatures ……………...… 14

 

Ana Socalici, Erika Ardelean, Heput Teodor, Ardelean Marius, Ana Josan:

Solidification simulation of the continuous

cast blanks with micro-coolants added

 in the mould …………………………... 20

 

Ana-Luciana Rus, Frunză Dan: Grain

refinement and superplasticity of 2024

 aluminium alloy ………………………. 26

 

? FOSECO Turbostop system – reference list… I-II

? Press Release..............…..…………..…...... III-VII

? New books, published by romanian metallurgical

foundation……………….……….....…..... VIII-IX

abstract

metalurgia International 8/2007

 

 

Key words: Al-Si alloys, wear strength, anti-friction properties

VARGA Bela, Bedő Tibor,  Cozma R., Bobancu S.: Wear strenght of Al-Si alloys fused with low-melting elements

Metalurgia International (vol. XII), no.8, 2007, p. 5

The paper discusses anti-friction and wear strength properties of standard and non-standard Al-Si alloys, in dependence on their conditions of smelting casting. The wear behaviour of the two alloys shows that for the tested compositions wear strength is determined mainly by the elements dissolved in the alpha solid solution, and less by the primary segregations of silicon.

 

Key words: Food processing, High Pressure Processing (HPP),         pasteurization

GEAMĂN  Virgil: High pressure processing of food

Metalurgia International (vol. XII), no.8, 2007, p. 10

In addition to traditional thermal pasteurization, other technologies can satisfy the definition of pasteurization for certain foods: ohmic heating, microwave heating, steam and hot water treatments, high pressure processing (HPP), UV radiation, irradiation, pulsed electric field, and chemical treatments. Other technologies, such as filtration, infrared and high voltage arc discharge, may also have the potential to be used alone or in combination with other treatments.

The paper presents some experimental data obtained by manufacturing due high processing of food – a new tendency in the food industry.

 

Key words: laser cladding, nickel alloy, microstructure

Simona BOICIUC, Sanda LEVCOVICI, LEVCOVICI  Dan T.: Structural modifications in laser cladding layers heating up at different temperatures

Metalurgia International (vol. XII), no.8, 2007, p. 14

In hereby work paper it was reported the structural modifications of several many-layer claddings achieved by powder injection of Ni alloy from the Ni-Cr-B-Fe-Al system, in the bath melt by CO2 laser in continuous wave, heating up at different temperatures. It was pursued the variation of layer cladding hardness with the temperature, and with the keeping time.

 

Key words: casting, solidification, simulation, steel, micro-coolants, mould

Ana Socalici, Erika Ardelean, Heput Teodor, Ardelean Marius, Ana Josan: Solidification simulation of the continuous cast blanks with micro-coolants added in the mould

Metalurgia International (vol. XII), no.8, 2007, p. 20

The paper presents the obtained results in case of simulating the solidification of the continuous cast blank with micro-coolant addition in the mould. The simulation was made with the help of our own program TURNCON, carried out in the language C++ and which works under platforms Win32 (that means Windows 95, 98, Me, NT4, 2000, XP – with an Intel processor). The program allows both a uniform distribution of the micro-coolants and a haphazard distribution, respectively a haphazard repeatable distribution. The diagrams shown represent the

blank solidification simulation in case of the haphazard repeatable distribution of the micro-coolants in the mould of the continuous casting machine, because this case is the closest to their addition in the industrial practice.

 

Key words: aluminum alloy, superplasticity, thermomechanical processing, flow stress, strain rate

Ana-Luciana Rus, Frunză Dan: Grain Refinement and superplasticity of 2024 aluminium alloy

Metalurgia International (vol. XII), no.8, 2007, p. 26

In recent years, there was a rapid growth in interest of superplastic aluminum alloys. A few alloys have been designed for superplasticity but it is likely that this approach is limited in view of the cautions, outlook of designers and metal users, particularly those in the aerospace sector. The dominant current approach is to take an alloy with well established service properties and to process it to develop superplasticity.

The experiments were conducted using a commercial 2024-T3 aluminum alloys produced by S.C. ALPROM S.A. Slatina, Romania. The material was produced in the form of extruded bar with a diameter of 22 mm. Chemical composition (in wt%) of the received samples is: 4.955 Cu; 1.322 Mg; 0.437 Mn; 0.358 Zn; 0.300 Fe; 0.119 Si; 0.017 Cr; 0.005 Sn; 0.005 Sb; 0.005 Pb; 0.003 Ni; Al-balance.

Because the ductility of 2024 aluminum alloy as-received is small (tensile elongation smaller than 108% for round samples with gauge length of 25 mm and diameter of 5 mm, testied by tensile testing at the temperatures and strain rates used in this researches), the material was processed thermomechanical (this is a method to increase the ductility through grain refinement).

A special thermomechanical processing was developed for this alloy to obtain a fine structure before superplastic testing. The specimens from the received material with length of 60 mm and diameter of 22 mm, were homogenized at 5000C for 8 hour, reduced by hot rolling at 440÷4800C to 7 mm strip thickness and water quenched. Then the samples were cold rolled to 3 mm thickness. The specimens were fast heated up to high temperature (4800C), held for 10-15 minutes and then fast quenched in water followed by 30 minutes soaked at 3500C in order to make fine-grained structure stable.

Fine stable microstructures can be developed by thermomechanical processing of 2024 commercially aluminum alloy. The plastic deformation of this material was investigated in a temperature range between 450÷4800C and the strain rate range of 1x10-3÷1x10-2 s-1. The deformation characteristics were correlated with the results of microstructure investigation. The material have a potential for superplastic behavior during deformation at temperatures of about 4600C and 4800C. Tensile elongations to failure in excess of 200% were obtained in strain rate range 1x10-3÷1.5x10-3 s-1 at 4600C and 5x10-3 s-1 at 4800C, and materials may be bulge formed. The grain size after thermomechanical processing was 5÷8 μm. The microstructure exhibited exceptional stability at 4600C, due to the presence of precipitates of Al-Mn.

 

Attention !

 

E According to paragraph 2.6 of license agreement between EBSCO Publishing Inc. (U.S.A.) and FUNDAŢIA METALURGIA ROMÂNĂ   (ROMÂNIA) the  journals METALURGIA and METALURGIA INTERNAŢIONAL are  included in EP  Products, starting  from July 1st, 2006.

E These journals are included on EBSCO’s site: www.ebscohost.com , chapter „Computers and Applied Sciences Complete”, pozitions 1026 and  1027.

E Starting from January 1st  the  journal METALURGIA INTERNATIONAL is also in the SCOPUS database, belonging to ELSEVIER BIBLIOGRAPHIC DATABASES – Amsterdam (Netherlands).

 

1.      The “METALURGIA INTERNATIONAL” magazine receives manuscripts of papers including basic  scientific research and industrial  research in the following fields: metallurgy, materials science and engineering and different relating processes.

2.      Original papers not previously publishing  in any other journal, or not sent for publishing before, are accepted.

3.      After publication, the copyright is transferred to the publishing house.

4.      Every manuscript will be referred, their reports form the basis of the Editor’s decision.

5.      The manuscripts sent to the Editor  will not returned to the author, even  they are not published.

6.      The manuscripts will be sent to the following address:

METALURGIA INTERNATIONAL

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