7075

6617

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1390

دوازده، 77ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

مهدي صالحي، حميدرضا سليمي جزي

24/7/91

مرتضي شمعانيان، بهروز موحدي

1396/09/19

كتابنامه

مواد

مهندسي مواد

ID6617

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Characterization of Copper Coatings Deposited by Thermal Spray for Thermal and Electrical Conductivity Applications Morteza Aghaee m aghaee@ma iut ac ir February 20 2012 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiDr Mehdi Salehi Prof supervisor E mail isrec@cc iut ac irDr Hamidreza Salimijazi Assis Prof supervisor E mail hrjazi@cc iut ac irAbstractIn the current study copper coatings were succesfully deposited on steel substrates by thermal spraying forelectrical and thermal conductivity applications The commercially available copper powder particles wereused for deposition by a HVOF system using three different fuel oxygen ratio The powder size distributionwas measured by laser diffraction method After deposition coatings were seperated from substrate and themorphology and microstructure of the coatings and initial copper powders were evaluated by optical andscanning electron microscopy SEM The X ray diffraction pattern XRD of copper powder and coatingswere utilized to determine phase composition and the residual stresses induced during deposition Oxygencontent of coatings was determined by LECO T300 oxygen determiner The thermal conductivity of coatingswas measured in two directions through thickness TT and in plane IP by laser flash apparatus Theelectrical resistivity of coatings was measured in the same directions by the four point probe method Crosssection microstruccture of coatings revealed the general defects of thermal spray coatings such as pores intersplat cracks and diffusion bonding between splats Oxygen content of coatings was two times higherthan that of copper powder The thermal and electrical conductivity of coatings were different in plane andthrough thickness of the coatings Image analysis revealed that the number of splats are different in twodirections and as the number of splats changes in one direction the thermal and electrical conductivitychanges Thermal and electrical conductivity of coatings improved after annealing for 6 hours at temperatureof 600 C The grain size within the splats became larger after heat treatment indicated that recrystallizationaccured during heat treatment This recrystallization was due to existance of the high amount of strain energyin the coatings Annealing can relief the effects of particle strains that have been created during the coatingprocess It concluded that splat interfaces were the prominent phenomena for decreasing the thermal andelectrical properties Moreover residual strains and the grain structure within the splats were the other sourcesfor decreasing properties Key words Copper coatings HVOF Anisotropy of properties Thermal conductivity Electricalresistivity

مهدي صالحي، حميدرضا سليمي جزي

مرتضي شمعانيان، بهروز موحدي