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

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.; Makroskooppisiksi metallisiksi laseiksi (bulk metallic glass, BMG) kutsutaan metalliseoksia, jotka on pystytty jaahdyttamaan yli millimetrin paksuisina koko alijaahtyneen alueen lapi lasisiirtymalampotilaan asti ilman, etta on paassyt tapahtumaan havaittavaa kiteytymista. Jaahdytyksessa syntynyt amorfinen metalli tayttaa lasin termodynaamisen maaritelman: kuumennettaessa yli lasisiirtymalampotilan metastabiili alijaahtyneen sulan alue esiintyy ennen kiteytymista. Amorfisten metalliseosten tuottamiseen tunnetaan monia menetelmia. Tuotettujen amorfisten metallikappaleiden materiaaliominaisuudet ja valmistettavuus riippuvat kaytetyista valmistusmenetelmista ja laitteistoista. Naiden valmistuslaitteistojen tutkiminen ja kehittaminen edistaa seka amorfisten metallien kaytannon sovelluksia etta edistaa sulien ja amorfisten materiaalien perustieteita. Tassa vaitostyossa tutkitaan eri valmistuslaitteistojen kykyja ensin kirjallisuutta ja haastatteluja kayttaen, seuraavaksi…