Wyniki wyszukiwania - BazTech

1

Microstructure characterization of ultrafine grained Cu alloys processed by methods with cyclic scheme of deformation

Rodak K.

Inżynieria Materiałowa

|

2018

|

Vol. 39, nr 2

46--55

EN

COT (compression with oscillatory torsion) is a simple process that has the ability to deform bulk metallic samples. Performed investigations show that this method of deformation leads to grain refinement of Cu–Cr and Cu–Fe alloys. The grain size obtained via the dislocation subdivision mechanism associated with generation of non-equilibrum grain boundaries is in the UFG range. Large fraction of grain boundaries have low angles of misorientation. The limitation of the grain refinement and creation of low angles boundaries can be attributed to the extensive dynamic recovery. However, recrystallization process and deformation twinning plays a crucial role in grain refinement resulting in grain refinement to the nanoscale. The present overview shows that many structural elements accompanying formation UGF structure influence on understanding of the microstructure–properties relationship in these materials.

PL

Prezentowana praca ma na celu scharakteryzowanie zmian mikrostruktury zachodzących w stopach miedzi CuCr0,6 (C18200) i CuFe2 (C19400) podczas rozdrabniania ziarna z wykorzystaniem metod RCMR i COT. Stopy CuCr0,6 i CuFe2 należą do grupy stopów umacnianych wydzieleniowo. W związku z tym w pracy przedyskutowano również wpływ struktury wyjściowej (stan materiału po przesycaniu oraz starzeniu) na kształtowanie rozdrobnionej struktury. Przedstawione problemy mogą być pomocne w pokazaniu pełnego obrazu procesów strukturalnych towarzyszących kształtowaniu się ultradrobnoziarnistej struktury stopów miedzi podczas cyklicznego odkształcania SPD.

2

Napięcie powierzchniowe ciekłych stopów Cu-Fe

Siwiec G.

Rudy i Metale Nieżelazne

|

2010

|

R. 55, nr 12

848-850

PL

W artykule przedstawiono uzyskane metodą kropli leżącej w temperaturach 1473 K oraz 1673 K, wyniki pomiarów napięcia powierzchniowego ciekłych stopów miedzi z żelazem o zawartości 0,01 do 0,05 ułamka molowego Fe. Badania przeprowadzone zostały przy użyciu mikroskopu wysokotemperaturowego sprzężonego z kamerą oraz komputerem wyposażonym w program umożliwiający sterowanie parametrami pracy, rejestrację i analizę obrazu. Przy wyznaczaniu napięcia powierzchniowego wykorzystana została procedura obliczeniowa, polegająca na estymacji metodą najmniejszej sumy kwadratów, parametrów układu równań różniczkowych opisującego kształt leżącej kropli cieczy. Na podstawie przeprowadzonych badań stwierdzono, że wzrost zawartości żelaza w stopach Cu-Fe prowadzi do podwyższenia wartości napięcia powierzchniowego. Wzrostowi temperatury badanych stopów, podobnie jak w przypadku czystych metali oraz zdecydowanej większości układów dwu- i wieloskładnikowych, towarzyszy spadek napięcia powierzchniowego.

EN

In the paper, the results of surface tension measurements at 1473 K and 1673 K with the use of the sessile drop method, concerning liquid copper-iron alloys with 0.01 to 0.05 Fe molar fractions, have been presented. The experiments were conducted using the measuring apparatus PR-37/1600 produced by the Industrial Electronics Institute in Warsaw. It consisted of a high-temperature pipe furnace allowing the observation of a sample placed inside a horizontal reaction chamber (called a high-temperature microscope) and a camera, both coupled with a computer equipped with a program for the device work parameter control as well as for recording and analyzing pictures. The program was used for measurements of appropriate geometric parameters of liquid alloy drops which were necessary for surface tension evaluation. In order to determine the surface tension, a computational procedure based on the least square estimation of the parameters of the differential equation system was used, describing the shape of a sessile drop of liquid using coordinates of points placed along a curve that forms the outer contour of the drop cross-section. The experiments showed that a higher Fe content in Cu-Fe alloys led to the increase in surface tension. A temperature rise of the investigated alloys, similarly to pure metals as well as a great majority of binary and multicomponent systems, is accompanied by the decrease in surface tension.

3

Influence of iron on the surface tension of copper

Oleksiak B., Siwiec G., Blacha A., Lipart J.

Archives of Materials Science and Engineering

|

2010

|

Vol. 44, nr 1

39-42

EN

Purpose: In the paper, the results of surface tension measurements at 1473 K and 1673 K with the use of sessile drop method, concerning liquid copper-iron alloys with 0.01 to 0.05 Fe molar fractions, are presented. The aim of the study was to determine the effects of iron and temperature on the surface tension of copper. Design/methodology/approach: The experiments were conducted with the use of sessile drop method at 1473 K and 1673 K, in an argon atmosphere. For the investigations, a measuring apparatus PR-37/1600, produced by the Industrial Electronics Institute in Warsaw, was used. It consisted of a high-temperature pipe furnace, allowing the observation of a sample placed inside a horizontal reaction chamber (called a high-temperature microscope), and a camera, both coupled with a computer equipped with a program for the device work parameter control as well as for recording and analyzing pictures. The program was used for measurements of appropriate geometric parameters of liquid alloy drops which were necessary for surface tension evaluation. In order to determine the surface tension, a computational procedure, based on the least square estimation of the parameters of the differential equation system, was used, describing the shape of a sessile drop of liquid using coordinates of points placed along a curve that forms the outer contour of the drop cross-section. Findings: The experiments showed that a higher Fe content in Cu-Fe alloys led to the increase in surface tension. A temperature rise of the investigated alloys, similarly for pure metals as well as a great majority of binary and multicomponent systems, is accompanied by the decrease in surface tension. Practical implications: Surface tension has a significant impact on obtaining, refining and casting of metals and alloys. Thus, the knowledge of this parameter may be useful for both a description of phenomena that occur during these processes and their improvement. Originality/value: The presented results may be the first literature data regarding surface tension of Cu-Fe alloys with 0.01 to 0.05 Fe molar fractions.