8123

7521

كارشناسي ارشد

مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1391

يازده،68ص: مصور،جدول، نمودار

ص.ع.به فارسي و انگليسي

حميدرضا سليمي جزي، محمدعلي گلعذار

18/8/92

محمدحسن عباسي، فتح ا... كريم زاده

مهندسي مواد

ID7521

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

70 Nucleation and Growth Transformations in Vacuum Plasma Sprayed Ti Al V Alloy Zahraalsadat Mousavi Email address Z Mousavijervekani@ma iut ac ir Date of Submission January Department of Materials Engineering Isfahan University of Technology Isfahan Iran Degree M S Language Farsi Supervisor Hamid Reza Salimijazi Assis Prof E mail golozar@cc iut ac ir Supervisor Mohammad Ali Golozar Prof E mail hrjazi@cc iut ac ir Abstract Because of the nature of the plasma spray processes physical and mechanical properties of the vacuum plasma sprayed structures of Ti Al V alloys are completely different compared to conventionally manufactured alloys In order to reach the desirable mechanical and physical properties vacancy and internal defects must be reduced splats boundaries must be eliminated and the optimal phase compositions should be obtained through the post deposition heat treatment In order to have appropriate heat treatment processes it will be needed to study the kinetic behavior of the as sprayed microstructure at elevated temperatures In the current study the kinetics of solid transformations in Ti Al V alloys produced by vacuum plasma spraying process was studied based on Johnson Mehl Avrami JMA theory In the kinetic behavior of this alloy the dependency and lack of equality of the transformation rate constant with temperature caused an irregularity at C This irregularity showed deference between transformation mechanism above and below C At lower temperature C curves constant gradient showed lack of change in the transformation mechanism including homogeneous nucleation and grown of phase At higher temperature C the gradient change indicated change in the transformation mechanism first mechanism was formation of phase grain boundary and second mechanism was plate nucleation and grown from the grain boundaries The value of the transformation rate constant in the kinetic study of the as sprayed Ti Al V alloy was much higher than that produced from casting method By using the results obtained from kinetics of phase transformation at different constant temperatures TTT diagram for the as sprayed Ti Al V alloy was developed PDF created with pdfFactory trial version www pdffactory com

حميدرضا سليمي جزي، محمدعلي گلعذار

محمدحسن عباسي، فتح ا... كريم زاده