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1

The effect of deformation degree on the microstructure of the 6060 aluminium alloy

Koralnik M., Adamczyk-Cieślak B., Kulczyk M., Mizera J.

Archives of Materials Science and Engineering

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2017

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Vol. 85, nr 2

80--85

EN

Purpose: All results obtained in the present study allowed to analyse the changes in the microstructure and texture of the commercial 6060 aluminium alloy, after deformation process by severe plastic deformation. There were compare two deformation degree samples received by cumulative hydrostatic extrusion. Design/methodology/approach: The samples of the 6060 alloy were subjected to a onepass and three-passes extrusion process and next the age hardening. The microstructure changes were investigated by using transmission and scanning electron microscopy. To study the texture evolution the X-ray diffraction were made. Findings: The microscopic observations results presented the refinement of microstructure as a result of deformation process. The evolution of fibrous character of texture was observed. There were noted the disappearance of fibrous component <100> during subsequent deformation processes and generation the fibrous component <111> after high deformation degree. In addition, for each state, the presence of cubic texture component was recorded. Research limitations/implications: For the future research are planned to analyse changes in mechanical properties after hydrostatic extrusion combinate with age hardening of investigated materials. Originality/value: The paper focuses on the investigation of microstructure and texture evolution after modern method of plastic deformation.

2

Evaluation of Sb effect onto eutectic Si changes and mechanical properties in an 4xxx Al cast alloys series

Hurtalova L., Tillova E., Chalupova M., Farkasova M.

Production Engineering Archives

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2014

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Vol. 3, No. 2

2--5

EN

The purpose of this article is to examine the effect of modifier based on AlSb10 on the structure and mechanical properties of the AlSi7Mg0.3 and AlSi6Cu4 cast alloys. The changes of these parameters were studied on samples in untreated states (without heat treatment). Structural changes were studied on light and scanning electron microscopes. Several types of etching were used, which included normal black and white etching (0.5% HF), colour etching (Weck-Al) and deep etching (HCl), for studying structural parameters morphology. The influence of modifier on mechanical properties (UTS, Brinell hardness test) was studied at room temperature. The present work shows that the antimony has not had a significant effect on mechanical properties (UTS, Brinell hardness test), but structural parameters were changed.

3

Wykrywanie niejednorodności materiału i lokalnych zmian mikrostruktury metodą prądów wirowych

Babul T, Jończyk S., Samborski T., Włodarczyk S.

Przegląd Spawalnictwa

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2013

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R. 85, nr 12

25--28

PL

Celem badań było określenie możliwości wykrywania lokalnych różnic we właściwościach części wykonanych ze stali 40HNMA, spowodowanych obróbką cieplną, obróbką powierzchniową oraz miejscowymi przypaleniami szlifierskimi. Zmiany te mają istotny wpływ na trwałość wyrobów, zwłaszcza kół zębatych. Zastosowano układ pomiarowy nowej generacji: Wirotest 302 oraz sondy o zróżnicowanej częstotliwości nominalnej od 250 kHz do 2 MHz. Dokonano oceny wpływu zmian strukturalnych, stanu powierzchni, a także obecności pęknięć na charakterystyki wiroprądowe. Badania potwierdziły także skuteczność wykrywania lokalnych zmian mikrostruktury spowodowanych przypaleniami szlifierskimi. Wyniki badań zweryfikowano przez pomiar mikrotwardości i chropowatości.

EN

Numerical simulations play an increasingly important role in nondestructive testing. They are widely used for the development of testing methods to confirm their effectiveness. Their main purpose is to support the analysis and interpretation of the research results. The paper shows the possibilities of ultrasonic testing modeling on immersion testing of composite test piece example. In the component made of carbon-epoxy composite, intentionally created defects are located. The defects were made by lamination of thin, flat, rectangular teflon inserts of known dimensions. The ultrasonic immersion tests of the component are compared with the results of simulations carried out for the created numerical model. The results showed the high value of the numerical simulation.

4

Non-destructive metallography & replica method for inspection connecting rod material and cracks detection

Kovacevic Z., Karastojkovic Z., Aleksic V.

Production Engineering Archives

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2013

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Vol. 1, No. 1

22--24

EN

Testing of materials properties is usually a discipline for the quality assurance during manufacturing processes. In condition monitoring, certification or upgrading of existing plants and in failure analysis similar benefits from non-destructive testing of materials properties can be achieved. Another benefit from the Non-Destructive Metallography (NDM) is that the test can be made on-site. NDM is a well established and proven tool to help determine the integrity of generator and hydro turbine components during their life-cycle in power plant environments. On-site metallography of components makes it possible to evaluate the microstructure of materials. It allows microstructural analysis of large components that are difficult to move or not permitted to be destructively tested, enabling rapid evaluation of the material. Here are monitored the microstructural changes and crack detection in St 35 connecting rod steel after approximately 15 years in service. The paper includes a short description of the replica method as a technique for microstructural examination of components by using non-destructive testing method.

5

Changes of microstructure in CuNi25 alloy deformed at elevated temperature

Sakiewicz P., Nowosielski R., Griner S., Babilas R.

Archives of Materials Science and Engineering

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2011

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Vol. 50, nr 2

98-109

EN

Purpose: The aim of this paper was to present behaviour of CuNi25 alloy during elevated temperature tensile tests and describe changes of microstructure of material after deformation at the range of the Ductility Reduced Area (DRA) in which the phenomenon of Ductility Minimum Temperature (DMT) is situated. Design/methodology/approach: Numerous techniques were used to characterize properties of material: high temperature tensile tests, transmission electron microscopy (TEM), HRTEM, FFT. Findings: During the experimental studies the course of elongation and reduction of area curves has been determined. Morphology of material after deformation at elevated temperature was analysed. Research limitations/implications: Further studies should be undertaken in order to correlate effects, processes and mechanism existing and superimpose in material in range of Ductility Minimum Temperature phenomenon, it should help us understand high temperature properties of mentioned material. Practical implications: Knowledge about material properties during high temperature deformation leads to selection of the appropriate production parameters. Misapplication of parameters leads to multiplication of costs and often destruction of material during production or operating. Correct selection of technical and economical parameters of material production processes gives us supremacy in economic and technological competition. Originality/value: Investigations of this CuNi25 alloy complete knowledge about mechanical properties and help us develop correct parameters for more effective technologies for material production.

6

Wpływ odkształcenia i prędkości chłodzenia na zmiany mikrostruktury superdrobnoziarnistej stali konstrukcyjnej.

Snopek J., Knapiński M., Koczurkiewicz B.

Prace Naukowe Politechniki Warszawskiej. Mechanika

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2009

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z. 226

51-56

PL

Struktura stali po przeróbce plastycznej na gorąco uzależniona jest od prędkości chłodzenia materiału. Dynamika i temperatury charakterystyczne przemian fazowych zachodzących w stali podczas chłodzenia zależą dodatkowo od odkształceń, jakim poddano materiał przed rozpoczęciem chłodzenia. W pracy przeprowadzono numeryczne i fizyczne modelowanie procesów obróbki cieplno-plastycznej superdrobnoziarnistej stali konstrukcyjnej. Symulacja numeryczna procesu obróbki cieplno-plastycznej przeprowadzono za pomocą komercyjnego programu komputerowego TTSteel w celu wygenerowania modelowego wykresu OCTPc. Natomiast fizyczne modelowanie zrealizowano wykorzystując dylatometru DIL 805 wyposażonego w przystawkę plastometryczną. Próbki po odkształceniu i chłodzeniu poddano badaniom metalograficznym, dla określenia rodzaju mikrostruktury i wielkości ziarna. Prędkość chłodzenia dobrano w taki sposób, aby uzyskać struktury ferrytyczne z wydzieleniami perlitu lub bainitu.

EN

Structure of a steel after hot plastic working depends on cooling rate of the material. The dynamic and characteristic temperature of phases transformations accruing in the steel during the cooling depend on the deformation which was applied to the material before the cooling start. In this work the numerical and physical modelling of the termomechanical treatment was made using commercial program TTSteel to determine OCTPc diagram. Physical modelling was made using dilatometer DIL 805 A/D equipped with plastometric attatchment. Metalographical examinations were made on the sample after deformation and cooling, with the aim to define microstructure. The used cooling rates were selected in aim to obtain ferritic structure with colonys of pearlite and bainite.

7

The influence of long-term annealing on the microstructure of Elektron 21 magnesium alloy

Kiełbus A.

Inżynieria Materiałowa

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2008

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Vol. 29, nr 4

310-315

EN

Elektron 21 is a new magnesium based casting alloy for used to 200°C. The microstructural changes after long-term annealing at 520°C (2-48 h) and 350°C (500-5000 h) have been presented. For the microstructure observation, a OLYMPUS GX71 metallographic microscope and a HITACHI S-3400N scanning electron microscope were used. Quantitative examination was conducted using the Met-Ilo automatic image analysis program. The Elektron 21 alloy in as-cast condition is characterized by a solid solution structure a with precipitates of Mg12(Nd,Gd) intermetallic phase on grain boundaries. After annealing (solutioning) at 520°C a reduction of the number of Mgi2(Nd,Gd) phase precipitates was observed. Its area fraction falls with the extension of the treatment time from AA=6.55% (as cast state) to AA= 0.5% (24 h of treatment). Also, an increase of the solid solution a grain size was observed from A=649 um2 to J=3000 um2. After annealing at 350°C the precipitation of Mg41Nd5 phase was observed. Its area fraction falls with the extension of the treatment time from AA=3.55% (500 h) to AA=5.55 % (5000 h of treatment). The solid solution a grain size didn't change.

PL

Stop magnezu Elektron 21 jest nowym stopem przeznaczonym do pracy w temperaturze do 200°C. W artykule zaprezentowano zmiany mikrostruktury podczas długotrwałego wyżarzania w temperaturze 500°C (2-48 h) i 350°C (500-5000 h). Do badań mikrostruktury zastosowano mikroskop optyczny OLYMPUS GX71 oraz mikroskop elektronowy skaningowy HITACHI S-3400N. Ilościową ocenę mikrostruktury przeprowadzono z wykorzystaniem programu "Met-Ilo". Stop Elektron 21 w stanie lanym charakteryzuje się strukturą roztworu stałego z wydzieleniami fazy Mg12(Nd,Gd) na granicach ziaren. Po wyżarzaniu (przesycaniu) w temperaturze 520°C obserwowano zmniejszenie udziału objętościowego fazy Mg12(Nd,Gd) z poziomu AA=6,55% (stan lany) do poziomu AA=0,5% (po 24 h obróbki). Natomiast średnie pole powierzchni płaskiego przekroju ziarna roztworu stałego zwiększało się z A=649 um2 do A=3000 um2. Po wyżarzaniu w temperaturze 350°C obserwowano wydzielanie fazy Mg41Nd5. Jej udział objętościowy zwiększa się wraz z wydłużaniem czasu obróbki z AA=3,55% (po 500 h) do AA=5,55% (po 5000 h). Średnie pole powierzchni płaskiego przekroju ziarna roztworu stałego nie zmienia się.