Structure and some mechanical properties of Fe3Al-based cast alloys

• Autorzy: Jabłońska M. , Jasik A. , Hanc A.

Warianty tytułu

PL

Struktura i właściwości mechaniczne stopów na osnowie fazy Fe3Al

• Języki publikacji: EN

Abstrakty

EN

In the paper was studies the influence of chemical composition and temperature on the properties, microstructures, hardness and ordering process of intermetallics on the base closed to one of Fe3Al phase. The major problem restricting universal application of intermetallic phase base alloy from Fe-Al system is their low plasticity which leads to hampering their development as construction materials. The analysis were performed for two alloys i.e Fe28Al and Fe28Al-5Cr which were produced by casting and next were annealed for 8, 16 and 48 hours at 1000°C. Both alloys is closed to one of Fe3Al phase. Mechanical properties were measured by the uniaxial tensile test at room temperature and at 600°C. Some basic mechanical properties i.e. R0,2, Rm, A5, Z were determined. Were obtained increasing ductility with a increase the temperature test in air condition for both alloys. Structural examination was carried out using light microscopy and scanning electron microscopy. There observed that in Fe28Al alloy without Cr phases rich in Fe and Al, which can correspond to FeAlC0;5 were visible as well as phases rich in Zr. The precipitates rich in Cr and Zr were identified alloy with Cr which probably correspond to FeCr2 ZrC and Cr2Zr phases. The fractographs of destruction surfaces after tensile tests shown, that for both alloy at room temperature are brittleness and intergrannular. After the test at 600°C character of the fractures were changed (different). Were observed transgrannular cleavage for both alloys. The ordering process was analyzed by X-ray diffraction, M¨ossbauer spectroscopy. The studied alloys were prepared by melting in induction furnace under vacuum and next were gravitatively casted into cylindrical graphite moulds. After then samples were annealed at 1000°C for 8, 16 and 48 hours. Different behaviour of Fe-28Al and Fe-28Al-5Cr alloys after annealing were founded. Microstructures for both alloys was similar. Were indicated the presence of phases and precipitates in investigated alloys in the dendritic primary structure which wasn’t changes after the heat treatment process. Were observed the influence the time of annealing on the hardness alloys. Increasing time of annealing from 8h to 48h at 1000°C influenced on the increasing of hardness in Fe-28Al alloy and decreasing of hardness in Fe-28Al-5Cr alloy. X-ray diffraction method were obtained that the Fe3Al phase of DO3 type structure was stated only in the sample of Fe28Al alloy annealed for 48 hours. The FeAl phase appeared to be the main phase in the other samples. All the informations including a some of mechanical properties, analysis of microstructure, long range ordering during the heat treatment of studied alloys could be helpfully for technological processing this materials.

PL

W pracy przedstawiono wpływ składu chemicznego na właściwości, mikrostrukturę, twardość oraz proces porządkowania stopów na osnowie fazy Fe3Al. Badania prowadzono dla dwóch stopów: Fe28Al i Fe28Al-5Cr, które zostały wytworzone metodą odlewania próżniowego, a następnie poddane wyżarzaniu przez 8, 16 i 48 godzin w temperaturze 1000°C. Właściwosci mechaniczne obu materiałów wyznaczono na podstawie statycznej próby rozciągania w temperaturze pokojowej oraz w temperaturze 600°C. Wyznaczono podstawowe właściwości mechaniczne, takie jak: R0,2, Rm, A5, Z. Badania strukturalne przeprowadzono wykorzystując technikę mikroskopii świetlnej oraz skaningowej mikroskopii elektronowej. Zaobserwowano, iż w stopie Fe28Al bez dodatku Cr w strukturze tworzą się fazy bogate w Fe i Al, które scharakteryzowano jako FeAlC0,5. oraz fazy bogate w Zr jako jeden z mikrododatków. W stopie Fe28Al z 5% dodatkiem Cr ujawniono głównie tworzenie faz bogatych w Cr a takze w Zr, takich jak FeCr2 ZrC i Cr2Zr. Wykonane badania faktograficzne powierzchni zgładów powstałych po próbie rozciągania ujawniły, że charakter pękniecia stopów badanych w temperaturze pokojowej jest łamliwy i międzykrystaliczny. Po próbie przeprowadzonej w temp. 600°C przełomy miały charakter transkrystaliczny dla obu stopów. Proces porządkowania analizowano wykorzystując dyfrakcję rentgenowską, oraz spektroskopię efektu Mossbauer'a. Wykazano, że faza Fe3Al typu DO3 występuje tylko w próbce Fe28Al, która poddano wyżarzaniu przez 48 godzin. Fazę FeAl zaobserwowano w pozostałych próbkach.

Słowa kluczowe

EN

metal alloys; iron aluminides; static tensile test; microstructure

PL

stopy metali; statyczna próba rozciągania; mikrostruktura

• 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: 2009
• Tom: Vol. 54, iss. 3
• Strony: 731--739
• Opis fizyczny: Bibliogr. 8 poz., rys., tab.

Twórcy

autor

Jabłońska M.

autor

Jasik A.

autor

Hanc A.

• DEPARTMENT OF MATERIALS SCIENCE, SILESIAN UNIVERSITY OF TECHNOLOGY, 40-019 KATOWICE, 8 KRASINSKIEGO STR., POLAND

Bibliografia

• [1] P. I. Ferreira, A. A. Couto, J. C. C. de Paola, The effects of chromium addition and heat treatment on the microstructure and tensile properties of Fe-24Al(at. %), Materials Science and Engineering A192/193, 165-169 (1995).
• [2] J. W. Lee, C. C. Wu, T. F. Liu, The influence of Cr alloying on microstructures of Fe-Al-Mn-Cr alloys, Scripta Materialia 50, 1389-1393 (2004).
• [3] A. O. Mekhrabov, et al. Effect of ternary alloying elements addition on atomic ordering characteristics of Fe-Al intermetallics, Acta Materialia 47, 2067-2075 (1999).
• [4] Y. D. Huang, W. Y. Yang, Z. Q. Sun, Effect of the alloying element chromium on the room temperature ductility of Fe3Al intermetallics, Intermetallics 9, 119-124 (2001).
• [5] M. Jabłońska, K. Rodak, G. Niewielski, Characterization of the structure of FeAl alloy after hot deformation, Journal of Achievements in Materials and Manufacturing Engineering 18 (1-2), 107-110 (2006).
• [6] D. Kuc, G. Niewielski, M. Jablońska, I. Bednarczyk, Deformability and recrystallisation of Fe-Al intermetallic phase - base alloy, Journal of Achievements in Materials and Manufacturing Engineering 20, 143-146 (2006).
• [7] M. Jabłońska, E. Bernstock, A. Jasik, Microstructure and mechanical properties of intermetallics on the base of Fe-Al alloy obtained by casting, Archives of Materials Science and Engineering 28, 625-628 (2007).
• [8] A. Hanc, J. Kansy, G. Dercz, M. Jabłońska, L. Pająk, Ordering process of Al- Fe and Cr-Al-Fealloys, Acta Physica Polonica 114 6, 1545-1553.