10011

9242

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1393

دوازده، 76ص.: مصور، نمودار

ص.ع. به فارسي و انگليسي

احمد كرمانپور، رحمت اله عمادي

94/2/21

مرتضي شمعانيان، فتح اله كريم زاده

1396/09/27

كتابنامه

مهندسي مواد

ID9242

Evaluating the effects of precipitation hardening heat treatment on the microstructures and mechanical properties of the directionally solidified Ni base superalloy GTD 111 Arman dadkhah a dadkhah@ma iut ac ir January 18 2015 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors Ahmad Kermanpur Assoc Prof E mail ahmad k@cc iut ac irRahmatollah Emadi Assoc Prof E mail remadi@cc iut ac irAbstractThe Ni base superalloys possess high stability and strength at high temperatures andtherefore they are used in the manufacturing of gas turbine components The superalloyGTD 111 is frequently employed in the first stage blades of high power gas turbines Theappropriate microstructure and strength is gained through the application of directionalsolidification and precipitation hardening heat treatment In this research severaldirectionally solidified DS GTD 111 specimens were first manufacturd by the Bridgmanmethod under vaccum by the withdrawal rate of 6 mm min In order to determine phasetransformation temperatures the differential scanning calorimetry was conducted based onwhich the heat treatment temperatures were selected under the solidus temperature of1295 C Different cycles of the precipitation hardening heat treatments were applied to theDS specimens and effects of homogenization primary partial solution secondary partialsolution and aging heat treatments on microstructures were investigated In addition theeffect of secondary partial solution at temperatures of 910 C 980 C and 1050 C on theroom temperature tensile and stress rupture properties of the heat treated specimens wasevaluated The results showed that the GTD 111 alloy has a multi phase microstructureconsisting of austenitic matrix precipitate eutectic and two types of MC andM23C6 carbides Moreover homogenization treatment resulted in a uniform distribution ofthe precipitates It was also observed that partial solution after homogenization led to thegrowth and preferred distribution of the precipitates along the 100 direction Moregrowth of precipitates during secondary partial solution led to the splitting of the precipitates into a group of fine precipitates The stress rupture test results showed that aproper distribution of the precipitates and consequently a higher rupture life wasobtained in the heat treatment cycle including homogenization primary partial solution secondary partial solution at 980 C Keywords Precipitation hardening Directional solidification GTD 111 superalloy Partial solution treatment

احمد كرمانپور، رحمت اله عمادي

مرتضي شمعانيان، فتح اله كريم زاده