Microstructure and mechanical properties of Mg-2.5%Tb-0.78%Sm alloy after ECAP and ageing

• Autorzy: Bryła K. , Dutkiewicz J. , Rokhlin L. L. , Lityńska-Dobrzyńska L. , Mroczka K. , Kurtyka P.

Warianty tytułu

PL

Mikrostruktura i właściwości mechaniczne stopu Mg-2.5%Tb-0.78%Sm po procesie ECAP i starzeniu

• Języki publikacji: EN

Abstrakty

EN

The influence of ageing and Equal Channel Angular Pressing (ECAP) on the microstructure and mechanical properties of Mg-2.5%Tb-0.78%Sm alloy has been examined. The microhardness changes during ageing at 200ºC show a slight increase. The aged microstructure at maximum hardness contains Mg₁₂(Tb,Sm) - metastable β’ phase of size about 2-10 nm as dispersed precipitates. The orientation relationship between β’ phase and the matrix was found as follows: (0001) _Mg || (110) _β′, [2110] _Mg || [116] _β′. The ECAP passes were performed by two procedures: “I” - four passes at 350ºC; “II” - one pass at 370ºC, second pass at 340ºC and third pass at 310ºC. The grain size was reduced about 200 times as a results of ECAP process according “I” and “II” procedure. The grain refinement by ECAP improves significantly the compression yield strength and hardness. The Hall-Petch relationship was confirmed basing on microhardness measurements and the grain size after ECAP. The Mg ₂₄ (Tb,Sm) ₅ and Mg ₄₁ (Sm,Tb) ₅ particles smaller than 150 nm are located mainly at grain and subgrain boundaries and they prevent grain growth during ECAP processing. The microstructure evolution during ECAP can be described as dynamic recovery and continuous and discontinuous dynamic recrystallization.

PL

W pracy przeprowadzono badania mikrostruktury i właściwosci mechanicznych stopu Mg-2,5%Tb-0,78%Sm po procesie starzenia oraz po odkształceniu plastycznym metoda ECAP. Starzenie stopu w temperaturze 200ºC powoduje niewielki wzrost mikrotwardości. Mikrostruktura stopu starzonego o maksymalnej wartości twardości zawiera metastabilne drobnodyspersyjne wydzielenia Mg₁₂ (Tb,Sm) - β′ o wielkości 2-10 nm. Roztwór stały α-Mg wykazuje następujące zależności krystalograficzne z wydzielonymi cząstkami β′: (0001) _Mg || (110) _β′, [2110] _Mg || [116] _β′. Odkształcenie plastyczne metoda ECAP przeprowadzono stosując dwie procedury: „I” - cztery przejścia w 350ºC, „II” - pierwsze w 370ºC, drugie w 340ºC i trzecie przejście w 310ºC. Po procesie ECAP, dla obu procedur, nastąpiło dwustukrotne zmniejszenie wielkości ziarna. Zmniejszenie wielkości ziarna uzyskane metodą ECAP znaczaco poprawia twardość oraz granice plastycznosci przy ściskaniu. Stwierdzono zależność Halla-Petcha pomiędzy wartościami mikrotwardości oraz wielkości ziaren uzyskanymi w wyniku odkształcenia metodą ECAP. Cząstki Mg ₂₄ (Tb,Sm) ₅ i Mg ₄₁ (Sm,Tb) ₅ mniejsze niż 150 nm wydzielone na granicach ziaren i podziaren zapobiegaja ich wzrostowi podczas procesu ECAP. Zmiany mikrostruktury zachodzące podczas procesu ECAP można opisać procesami dynamicznego zdrowienia oraz dynamicznej rekrystalizacji.

Słowa kluczowe

EN

magnesium alloys with rare earth metals; ECAP; microstructure; ageing; mechanical properties

PL

stopy magnezu z metalami ziem rzadkich; ECAP; mikrostruktura; starzenie; właściwości mechaniczne

• Wydawca: Institute of Metallurgy and Materials Science of Polish Academy of Sciences ; Committee of Materials Engineering and Metallurgy of Polish Academy of Sciences
• Czasopismo: Archives of Metallurgy and Materials
• Rocznik: 2013
• Tom: Vol. 58, iss. 2
• Strony: 481--487
• Opis fizyczny: Bibliogr. 22 poz., rys., tab.

Twórcy

autor

Bryła K.

• Institute of Technology, Pedagogical University, ul. Podchorążych 2, 30-084 Kraków, Poland

autor

Dutkiewicz J.

• Institute of Metallurgy and Materials Science, Polish Academy of Sciences, Reymonta 25, 30-059 Kraków, Poland

autor

Rokhlin L. L.

• Baikov Institute of Metallurgy and Material Science, Russian Academy of Sciences, 49, Leninsky Prospect, 119991 GSP-1, Moscow, Russia

autor

Lityńska-Dobrzyńska L.

• Institute of Metallurgy and Materials Science, Polish Academy of Sciences, Reymonta 25, 30-059 Kraków, Poland

autor

Mroczka K.

• Institute of Technology, Pedagogical University, ul. Podchorążych 2, 30-084 Kraków, Poland

autor

Kurtyka P.

• Institute of Technology, Pedagogical University, ul. Podchorążych 2, 30-084 Kraków, Poland

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