13344

12163

كارشناسي ارشد

جوشكاري

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

۱۳۹۶

پانزده، ۹۹ص.:‌ مصور، جدول، نمودار

مرتضي شمعانيان، مسعود عطاپور

حميدزضا سليمي جزي، محمود منير واقفي

1396/12/15

كتابنامه

مواد

مهندسي مواد

ID12163

9 3 4 ريزسختي سنجي 17 01 3 4 ارزيابي استحكام برشي 27 11 3 4 مورفولوژي سطوح شكست 37 21 3 4 الگوي XRD از سطح شكست 47 تاثير زمان فرايند بر اتصاالت ايجاد شده 57 1 4 4 فازيابي و بررسي ريزساختاري اتصال ايجاد شده در زمان 02 دقيقه 67 2 4 4 فازيابي و بررسي ريزساختاري اتصال ايجاد شده در زمان 04 دقيقه 87 3 4 4 فازيابي و بررسي ريزساختاري اتصال ايجاد شده در زمان 06 دقيقه 18 4 4 4 فازيابي و بررسي ريزساختاري اتصال ايجاد شده در زمان 08 دقيقه 28 5 4 4 ريزسختي سنجي 58 6 4 4 استحكام برشي 68 7 4 4 مورفولوژي سطوح شكست 78 فصل پنجم نتيجهگيري و پيشنهادات 09 نتيجهگيري 09 پيشنهادها 29 منابع 39 چكيده التين 99 ده

99AbstractThe bonding of stainless steel to titanium and its alloys has attracted great attention in variousindustries including medicine aerospace and chemical In this study the effect oftemperature and time on the dissimilar bonding of UNS 32750 superduplex stainless steel toTi 6Al 4V alloy using a transient liquid phase method has been studied For this purpose atfirst samples were prepared with dimensions of 4x10x10 mm and their surface was preparedby grinding and degreasing with acetone The interlayer was made of pure copper forbonding The sandwich panels are placed in an appropriate fixture so that the middle layerbetween the two base metals is placed The samples were first placed in a vacuum chamberat 60 minutes and four different temperatures of 890 920 950 and 980 C After determiningthe best temperature from the selected temperatures the effect of time on constanttemperature was investigated The bonded specimens were cut off and subjected to standardmetallography methods for microstructural studies The optical microscope and the scanningelectron microscope were used to study the microstructure Also to determine the chemicalcomposition of the phases and also to study the change in the concentration of alloyingelements in the bonding zone an electron microscope equipped with energy dispersivespectroscopy was used The results of temperature change at constant time of 60 min showedthat with increasing temperature the isothermal solidification rate increased and at 980 C the joint zone experience isothermally solidification The analysis of EDS and EBSD showedthat although the temperature increased leads to isothermal solidification of the joints butdue to the greater diffusion of titanium to steel and the formation of Ti Fe based intermetalliccompounds the average hardness in the bonding zone increased and the bond strengthdecreases The highest bond strength was measured at 271 MPa at 890 C Also themorphology of the fracture surfaces indicates that the failure mode is turned into brittle withincreasing temperature The temperature of 890 C was chosen as the best temperature andthe effect of the bonding time at 890 C on the components was evaluated For this purpose four different times 20 40 60 and 80 minutes were used for bonding The results ofmicrostructural studies showed that at 20 min due to the low opportunity for diffusion ofalloying elements from the side of the middle layer to the base metals and vice versa therelatively high copper phases in the central region of the joint remained and thus Thetitanium diffusion toward steel and the formation of brittle intermetallic compounds arelargely prevented As the bonding time increases the time for the diffusion increases thusincreasing the dissolution of the base metal and increasing the width of the bonding zone Therefore two factors of increasing the width of the bonding area and increasing the brittleintermediate components in the bonding zone reduce the bond strength by increasing thebonding time The highest strength of 437 MPa was obtained for the joint created at 20minutes The electron microscope images of the fracture surfaces also indicate the formationof cleavage surfaces at a bonding time of 80 minutes which is the reason for the brittlefailure mechanism in the joints with the increase of bonding time As a result thetemperature of 890 C and the time of 20 minutes are the best condition for joint theTi 6Al 4V alloy to UNS 32750 superduplex stainless steel by transient liquid phasetechniques Keywords Transient liquid phase Ti 6Al 4V alloy UNS 32750 superduplex stainless steel isothermal solidification intemetallic compounds copper interlayer

مرتضي شمعانيان، مسعود عطاپور

حميدزضا سليمي جزي، محمود منير واقفي