7539

7011

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1391

دوازده،78ص.: مصور،جدول،نمودار﴿رنگي﴾

ص.ع.به فارسي و انگليسي

حميدرضا سليمي جزي، رحمت ا.. عمادي

9/12/91

مهدي صالحي، علي شفيعي

مهندسي مواد

ID7011

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

79 The Effect of the Plasma Gas and Process on the Plasma Erossion Behavior of Plasma Sprayed Yttria Coating Majid Saeidfar m saeidfar@ma iut ac ir November 12 2012 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisores Dr H R Salimijazi hrjazi@cc iut ac ir Dr R Emadi remadi@cc iut ac irAbstractPlasma spray processes are widely used for ceramics coatings Lots of efforts the qualityof the coatings can be improved via increasing the in flight particles temperature and theirmelting conditions By increasing the enthalpy of the plasma gases and also improvementof the plasma jet heat transfer through replacement of the conventional gases such asargon and helium with molecular gases such as CO2 CH4 the temperature and meltingconditions of the in flight particles can be improved Yttrium oxide Yttria has propertiesin the form of coating with high chemical and heat stability and no phase changes up to2200 0C One of important application of yttria is its use in semiconductor manufacturingindustry as a protective coating against plasma erosion atmosphere In this research Yttria powders were sprayed by two plasma guns argon and CO2 CH4 plasma onaluminum substrates Some of their physical and structural properties were investigated Microscopic images of yttria coating deposited by CO2 CH4 plasma have shown bettercohesion less porosities and non melting particles due to the higher temperature of the in flight particles The results obtained from the phase analysis tests indicated the formationof a small amount of monoclinic phase This phase could be converted to the cubic phaseafter heat treatment of the coatings To study the erossion resistance of the yttria coating two systems of plasma plasma focus dry etching and reactive ion were employed Theresults confirmed better resistance of yttria coatings deposited by CO2 CH4 gases inplasma focus etching atmosphere The effective factor is the smaller amount of structuraldefects wider splats and lower density of splat boundaries on the surface of the coating Keywords Yttria CACT and SG 100 Plasma Torch Microstructue Phase analysis Reaction ion etching RIE Plasma focus PF

حميدرضا سليمي جزي، رحمت ا.. عمادي

مهدي صالحي، علي شفيعي