5485

5145

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1389

ده،159ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

مهدي صالحي، مهدي احمديان

محمد حسين عنايتي، علي اكبر عالم رجبي

24/7/89

محمد علي گلعذار،سعيد رضا بخشي

مهندسي مواد

ID5145

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Tribological behavior of micro and nanostructured WC Co coatings on copper substrate prepared by HVOF thermal spray process Saeid Salavati Saeed salavati@ma iut ac ir July 2010 Department of Materials Science and Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Professor Mehdi Salehi ISREC@cc iut ac ir Professor Mehdi Ahmadian Ahmadian@cc iut ac ir Abstract In this research improvement of tribological behavior of copper based on it s application in continuous casting moulds and increasing their service life was investigated For this purpose coating through surface engineering methods was selected Different coating materials were investigated by ANSYS software to identify thermal behavior of them on copper plates of the moulds Finally WC Co cermet was selected for coating on the copper substrate Different composition of this cermet was used as the microstructure powder WC 10Co 4Cr Wc 12Co WC 17Co and for nanostructured powder ball milling process by SPEX 8000 was used for milling microstructure WC 10Co 4Cr powder and then agglomerated by spry drying method Investigations on coatings characteristics were done by XRD phase analysis SEM ball on disk wear test in mould operation temperature 350 C micro hardness fracture toughness coating cohesion testing and high temperature oxidation TG Result of high temperature wear test show that vertical cracks can take place because of difference between thermal expansion coefficient and related stresses in the interface of coating and substrate It was identified that using Ni Cr bondcoat between coating and substrate has not positive effect on wear behavior cohesion and crack resistance of the coating Through microstructure coatings with different composition WC 10Co 4Cr show better fracture toughness and hardness and wear resistance Nanostructure coating had higher hardness and fracture toughness that microstructure coatings and it s wear resistance and cohesion strength was near to the microstructure coatings Investigation of high temperature wear behavior of the coatings show that higher content of the binder cobalt phase lead to more cohesion of the coating to substrate and decrease crack formation in the coating Finally WC 10Co 4Cr microstructure coating was selected for continuous casting copper plates Key Words HVOF WC Co Copper Wear Nanostructured coatings

مهدي صالحي، مهدي احمديان

محمد حسين عنايتي، علي اكبر عالم رجبي

محمد علي گلعذار،سعيد رضا بخشي