5836

5451

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1389

[نه]،101ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

حسين ادريس

6/2/90

محمد حسن عباسي، مرتضي شمعانيان

مهندسي مواد

ID5451

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Fabrication of Ni nanoparticles by mechanochemical process and the control of particle size by compositional factors Masih Banki Email address masih banki@ma iut ac ir Date of Submission 13 July 2010 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor s Name Hossein Edris Associate Professor h edris@cc iut ac ir Abstract In the current investigation fabrication of Nickel nanopowders using mechanochemical process and the effect of milling time on particle size has been studied Furthermore the effect of using magnesium chloride as well as additional magnesium in respect to stoichiometric ratios as process control agent PCA on reaction progress and the size of Ni nanoparticles has been investigated In this regard planetary ball mill with maximum speed of 500 rpm was used After mechanical milling to separate the Ni nanoparticles the processed samples were leached in 10 HCl for 5 hours and rinsed with double distilled water Internal structural changes and morphological evaluations of powder particles during mechanochemical process were characterized by means of X ray diffraction XRD and Scanning electron microscope SEM In mechanical milling of the stoichiometric powder mixture continuing milling from 35 up to 40 h and further mechanical milling form 40 to 50 h results in a reduction and an increase in the particle size of Nickel nanopowder respectively Excessive Mg addition as PCA reduces the length of the reaction time comparing to the stoichiometric mixture Moreover the more the amount of Mg causes the finer the Ni powder particle The addition of MgCl2 as PCA to the initial powder mixture reduces the commencing reaction time comparing to milling of stoichiometric mixture of NiCl2 and Mg powder first stage Also the addition of MgCl2 as PCA causes a delay in finishing time of the reaction comparing to first stage and Milling the powder mixture with additional Mg second stage Excessive amount of MgCl2 leads to the crystalline size reduction The effect of MgCl2 addition on controlling and reducing the crystalline size of Ni is greater than the addition of Mg Keywords Mechanical milling Mechanochemical process Ni nanoparticles process control agent PCA

حسين ادريس

محمد حسن عباسي، مرتضي شمعانيان