Facilities for production of bulk amorphous metals, and evaluation thereof using alloy Zr55Cu30Al10Ni5

Erno Soinila

    Research output: ThesisDoctoral ThesisCollection of Articles

    Abstract

    Bulk metallic glasses (BMG) are alloys that can be solidified into a diameter larger than 1 mm without detectable crystallization. The resulting amorphous solid state satisfies the thermodynamic definition of a glass: upon heating above a glass transition temperature, they reach a metastable super-cooled liquid region before crystallizing. There are many known methods for producing amorphous metals. The material properties and the ease of manufacturing amorphous metal specimens depend on the manufacturing methods and facilities used. Studying and developing such facilities contributes both to practical applications of these materials and to advances in basic science of liquid and amorphous states of matter. In this thesis, the merits of different facilities for producing bulk metallic glass are evaluated anecdotally using literature and interviews, and then in practice by designing, building and finally using different facilities to make various metallic glass specimens with composition Zr55Cu30Al10Ni5 (at.%). The results demonstrate that the process and equipment for producing metallic glass can be significantly simplified by constructing a combined arc melter and tilt casting furnace. A novel design for such a furnace, using ultra-high vacuum fittings making it possible to tilt the entire chamber, eliminates the need to use separate furnaces for alloying and for casting, and enables a practical manner to produce metallic glass specimens of the highest purity and highest mechanical quality. Further shaping of bulk metallic glass preforms into large aspect ratio metallic glass parts was shown to be feasible, without elaborate process control, in a tensile viscous flow configuration. Induction heating specially designed preforms results in a self-stabilizing thermoplastic forming process for metallic glass wires. Magnetron sputtering was used to produce amorphous coatings of the same nominal composition as the BMG specimens, directly attached to heat sensitive polymeric materials. Adhesion was found to be controllable via sputtering process parameters.
    Translated title of the contributionAmorfisten metallien valmistuslaitteistot ja niiden arviointi seoksen Zr55Cu30Al10Ni5 avulla
    Original languageEnglish
    QualificationDoctor's degree
    Awarding Institution
    • Aalto University
    Supervisors/Advisors
    • Hänninen, Hannu, Supervising Professor
    • Bossuyt, Sven, Thesis Advisor
    Publisher
    Electronic ISBNs978-952-60-4691-4
    Publication statusPublished - 2012
    MoE publication typeG5 Doctoral dissertation (article)

    Keywords

    • amorphous metal
    • bulk metallic glass
    • arc melting
    • physical vapor deposition
    • induction heating

    Fingerprint

    Dive into the research topics of 'Facilities for production of bulk amorphous metals, and evaluation thereof using alloy Zr55Cu30Al10Ni5'. Together they form a unique fingerprint.

    Cite this