توليد و مشخصه يابي آلياژهاي نانو كريستالي آهن - نيكل به روش رسوب دهي الكتريكي

چكيده انگليسي :

Characterization of Fe Ni alloys produced by electrodeposition Amirreza Sanaty Zadeh a sanatyzadeh@ma iut ac ir 16 March 2009 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Co Supervisors Dr Ali Saidi a saidi@cc iut ac ir Dr Keyvan Raeissi k raeissi@cc iut ac ir Abstract Nanocrystalline materials are of technological importance due to their interesting properties such as their ductility high strength wear resistance and magnetic properties Because of their attractive properties there has been great emphasis on studying these materials Many synthesis techniques have been developed such as gas condensation ball milling chemical processing sol gel technique sputtering rapid solidification and electrodeposition Among the methods mentioned above electrodeposition is considered to have more eligibility because of some advantages In this method the deposition can be proceeded under the normal condition of temperature and pressure which results in better control of process and lower costs for the equipments Production and characterization of nanocrystalline iron nickel alloys have been received a lot of attentions due to their interesting mechanical and magnetic properties The Fe Ni alloys fabricated by electrodeposition are used in the electronic industries for memory recording and storage devices NEMS MEMS and low CTE applications In this study nanocrystalline Fe Ni alloys were produced by electrodeposition Free additive chloride baths were used to lessen the impurities in produced alloys The influence of bath concentration current density and pulse current density was studied The chemical composition of alloys was determined by EDS semi quantitative analysis The investigations showed that the Fe content increased with decrease in Ni Fe ion ratio but the relationship is not linear This is because of anomalous co deposition behavior of Fe Ni system For the deposits with high iron content the structure was in the form of bcc With increase of Fe content to about 60 70 a dual phase alloy consisting of bcc and fcc crystal structures was formed Further increase in Fe content resulted in the formation of a single phase with fcc crystal structure Due to XRD patterns and previous studies the formation of FeNi3 intermetallic compound was also possible in this method The average grain size of Fe Ni alloys was about 8 16 nm which was increased with decrease of Fe content of the alloy Also an increase in current density led to higher content of Ni and coarser grains Applying high frequency pulse current density led to the increase in Fe content and decrease in grain size The hardness of deposits increased with decrease in grain size which was in consistent with Hall Petch relationship The study of magnetic properties of deposits by AGFM analysis showed an increase in saturation magnetization with increase in Fe concentration of bath and applying pulse current In addition a decrease in grain size led to lower coercivity although the Fe content of deposits increased The morphological studies showed that a uniform compact and smooth surface was observed with increase in Fe content of deposits and applying pulse current Furthermore the deposits had no porosity across its thickness Keywords Electrodeposition Fe Ni alloys Nanostructures Soft magnetic materials pdfMachine Is a pdf writer that produces quality PDF files with ease Produce quality PDF files in seconds and preserve the integrity of your original documents Compatible across nearly all Windows platforms if you can print from a windows application you can use pdfMachine Get yours now

صنعتي زاده، امير رضا

توليد و مشخصه يابي آلياژهاي نانو كريستالي آهن - نيكل به روش رسوب دهي الكتريكي

نانو ساختار , مواد مغناطيسي نرم