Determining the liquidus and ordering temperatures of the ternary Ni-Mn-Ga and quaternary Ni-Mn-Ga-Fe/Cu alloys

I. Aaltio*, Outi Söderberg, M. Friman, I. Glavatskyy, Y. Ge, N. Glavatska, S-P. Hannula

*Tämän työn vastaava kirjoittaja

    Tutkimustuotos: Artikkeli kirjassa/konferenssijulkaisussaConference contributionScientificvertaisarvioitu

    Abstrakti

    The high temperature transformations (e. g. liquidus, ordering temperature) of the alloys Ni47.7Mn31.2Ga21.1, Ni49.7Mn28.7Ga21.6, and Ni49.6Mn24.0Ga26.6, Ni47.3Mn30.3Ga20.3Fe2.1, Ni49.9Mn28.3Ga20.1Fe1.7, Ni51.3Mn14.4Ga26.3Fe8.0, Ni47.3Mn25.5Ga24.5Cu2.7, Ni48.3Mn29.7Ga21.1Cu0.9, and Ni49.4Mn23.3Ga25.6Cu1.7 were studied for the practical melting and annealing purposes. At first the chemical compositions (SEM-EDS) and the martensitic and magnetic transition temperatures (DSC, ac magnetic susceptibility) of the alloys were determined. High temperature DSC measurements were made in argon with 10 K/min. Two first measurements were carried out in the solid state (301-1273 K) and in the third measurement the material was melted (max meas. temp. 1573 K). The ordering temperature was obtained from the measurements in the solid state. As the e/a ratio was above 7.53 the ordering temperature was in the range of 1019-1039 K, otherwise a clear change was observed. The variation in heating and cooling was less than 5 K with small quaternary additions, but alloying of 8% Fe increased this difference to 18 K. Alloys with close Ni/Mn/Ga-ratio showed only minor differences in solidus and liquidus temperatures, but if there was a clear change in the Ni/Mn-ratio even those alloys having close e/a ratios showed a clear difference in melting behavior. When Ni/Mn is 1.5-with higher values not clear region could be determined.

    AlkuperäiskieliEnglanti
    OtsikkoESOMAT 2009 - 8th European Symposium on Martensitic Transformations
    ToimittajatP Sittner, Paidar, L Heller, H Seiner
    KustantajaEDP SCIENCES
    Sivut1-6
    Sivumäärä6
    ISBN (painettu)978-2-7598-0480-1
    DOI - pysyväislinkit
    TilaJulkaistu - 1 syyskuuta 2009
    OKM-julkaisutyyppiA4 Artikkeli konferenssijulkaisuussa
    TapahtumaEuropean Symposium on Martensitic Transformations - Prague , Tshekki
    Kesto: 7 syyskuuta 200911 syyskuuta 2009
    Konferenssinumero: 8

    Conference

    ConferenceEuropean Symposium on Martensitic Transformations
    LyhennettäESOMAT
    MaaTshekki
    KaupunkiPrague
    Ajanjakso07/09/200911/09/2009

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