14412

13023

جوشكاري

1397

شانزده، 99ص.: مصور، جدول، نمودار

عباس بهرامي، فتح‌الله كريم زاده

محمود منيرواقفي، كيوان رئيسي

1397/12/08

مواد

1397/12/12

ID13023

011 Fabrication and modification of Ni3Al intermetallic compound and evaluation of its joint properties by transient liquid phase method Mohammad Soltani Samani M SoltaniSamani73@gmail com Date of Submission Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Supervisors Abbas Bahrami Assistant Pro Email a n bahrami@cc iut ac irFathallah Karimzadeh Professor Email karimzadeh f@cc iut ac irAbstractIn this study the Ni3Al fabricated by vacume arc remelting process and differentpercentages of boron additive on the hardness and microstructure of Ni3Al was studied joining was performed by transient liquid process at vacuum furnace at 1050 C0 and theeffect of copper and AWS BNi 2 interlayer on the bonding region was investigated forfour times at 30 60 90 and 120 minutes By investigating the microstructure by opticalmicroscope it was determined that the density of dendrites increases as a result of theaddition of boron and space between the secondary arm decreases due to the increase inconstitutionally supercooling The results of the Vickers hardness test showed that thespecimen without boron had 190 HV hardness and white adding boron to 2 at reached352 HV In the following a transitional liquid phase method was used to jointing the Ni3Alintermetallic compound The joint area was investigated by optical and Scanning ElectronMicroscope Investigations showed that no Isothermally Solidifed Zone was formed atjoining with the AWS BNi 2 interlayer for 120 minutes and only with increasing time Brittle phases were reduced in Athermally Solidifed Zone at the Jointing EnergyDispersive X Ray Spectroscopy analysis on copper bonded specimens showed that theDiffusion Affected Zone is formed at joints Also the results showed that up to 90 minutesBrittle phases still exist in Jointing but by increasing the time to 120 minutes a solidsolution of copper was formed in the Jointing The investigation of microstructure changesin different regions along the Jointing and around it showed that in jointing with the AWSBNi 2 interlayer the highest hardness was formed due to the formation of nickel andchromium borides in the central line of the joint so that with increasing time Up to 120minutes the hardness increases to 722 HV The hardeness profile of jointing with Copperinterlayer it was seen that the hightest hardness was observed at Diffusion Affected Zonedue to the formation of brittle phases in this area Jointing hardness was increased byincreasing the time to 90 minutes and with increasing time to 120minutes the hardness in

عباس بهرامي، فتح‌الله كريم زاده

محمود منيرواقفي، كيوان رئيسي