Investigation of Bonding of Copper Sheets in Electronically Assisted Cumulative Rolling Process Reinforced with Titanium and Aluminum Boride Nanoparticles

Investigation of Bonding of Copper Sheets in Electronically Assisted Cumulative Rolling Process Reinforced with Titanium and Aluminum Boride Nanoparticles


Investigation of Bonding of Copper Sheets in Electronically Assisted Cumulative Rolling Process Reinforced with Titanium and Aluminum Boride Nanoparticles

نوع: Type: thesis

مقطع: Segment: masters

عنوان: Title: Investigation of Bonding of Copper Sheets in Electronically Assisted Cumulative Rolling Process Reinforced with Titanium and Aluminum Boride Nanoparticles

ارائه دهنده: Provider: Zohre Ghadimi

اساتید راهنما: Supervisors: Dr. Hamid Esfehani (Ph. D) - Dr. Yousef Mazaheri Roudbali (Ph. D)

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Dr. Omid Imantalab (Ph. D) - Dr. Mohsen Sheikhi (Ph. D)

زمان و تاریخ ارائه: Time and date of presentation: 2021.10.16 16:00

مکان ارائه: Place of presentation: Online

چکیده: Abstract: A nanostructure is a material with at least one nanoscale dimension below ۱۰۰nm. The project aims to synthesize the nanostructured T.A.B.O nanocomposite powder via electrospinning and to investigate the morphologies of the oxide, boride, and borate nanostructures. For this purpose, the T-A-O-B preforms with various molar ratios of B/(Ti+Al) were synthesized using titanium dioxide nanoparticles, the hydrated aluminum nitrate salt, boric acid, polyvinyl pyrrolidone as a polymeric matrix, and the electrospun fibers. The scanning electron microscopy (FESEM) showed that the composite nanofibers in a fibrous matrix turned into nanoparticles and nanowhiskers after being heat-treated at ۱۱۰۰˚C for ۱h. The binding energies were measured using X-ray photoelectron spectroscopy and the phases were identified via the X-ray diffraction method (XRD). The results confirmed the formation of a nanostructured ceramic powder, consisting of various ingredients i.e. the oxides (such as B-doped TiO۲, Al۲O۳), borides (TiB, Ti۲B۵, TiB۲, TiB۱۲, and AlB۲), and borates (TiBO۳ and Al۱۸B۴O۳۳). The results of simultaneous Thermal Analysis (STA) obtained from the nanostructured powder showed that the borides and borates are formed sequentially through the B۲O۳ melt-related reactions at ۸۰۰˚C. The electrospun-derived nanostructured powder containing ۰.۰۸ and ۰.۲۴ boric acid was coated on the copper sheet, considering the difference between the melting points of Cu and the nanoparticles. The coating process of the copper sheet was accomplished before the accumulative roll bonding. The accumulative roll bonding process for three uncoated copper sheets, and nanostructured copper-coated copper sheets with molar fraction equal to ۰.۰۸ for B / (Ti + Al) and copper-coated nanostructured powder sheets Molly equals ۰.۲۴ for B / (Ti + Al) done. the microstructure of copper sheets was investigated using scanning electron microscopy equipped with energy dispersive spectroscopy ( eds ) . the hardness of the samples after three passes of accumulative roll bonding process was measured by micro - hardness test . the average hardness , ۱۱۱ vickers hardness of copper sheet coated with nano - structure powder with nano - structure powder and the average hardness , ۵۳.۱ vickers hardness and vickers hardness of copper sheets were bare. Also, according to the results of tensile test, by applying three passes of the accumulative rolling bonding process, the tensile strength coated with nanostructured powder with a content of ۰.۲۴ boric acid equal to ۲۱۸ MPa and covered with nanostructured powder with a content of ۰.۰۸ Boric acid equal to ۲۰۰ MPa was obtained.