The Synthesis of Sialon Nano Particles by Sol- Gel Procedure and Investigation of Properties of its Erosion

, M.Sc. Thesis Sharif University of Technology Fathi, Hamed (Author) ; Nemati, Ali (Supervisor) ; Halali, Mohammad (Supervisor)

Abstract

Sialons are materials which crystallize in four elements system (Si-Al-O-N). These materials have been widely observed by researchers because of their suitable properties like: high toughness and strength in high temperatures, high resistance to corrosion and stability in thermal shock. Because of these properties,Sialons are anti erosion materials. In this research, by controling the situations, mullite has been synthesized by sol-gel procedure. Then the powder has been ground by ballmill for 12 hours and by spex for 30 minutes. Then the produced powder was mixed with distinct amount of graphite and nano silica and was nitrided in the furnace at 1500 ̊C and was heated for 5 hours. Also...

Effect of Mullite Content on HAp-Mullite Composite for Hard Tissue Application

, M.Sc. Thesis Sharif University of Technology Rahmani, Marzieh (Author) ; Faghihi Sani, Mohammad Ali (Supervisor) ; Solati Hashjin, Mehran (Supervisor)

Abstract

In this study effect of various mullite contents, as reinforcement phase, on phase combination, fracture surface and mechanical propertiese of hydroxyapatite- mullite composite has been investigated.
The used hydroxyapatite powder was synthesized through acid- base route and further calcination. XRD results demonstrated partially decomposition of HA in to β- TCP and CaO during the calcination. SEM image of the prepared HA powder showed that they were spherical and agglomarated.
The mixed HA with various amounts of the ball- milled mullite (10- 40 wt%)were pressed and sintered at 1350°C for 2h. Dominant phase in all composite samplese after sintering was Ca9Al(PO4)7.
Phase...

The Effect of Nano Mullite, Spinel as an Additive on Aluminum Based Composite

, M.Sc. Thesis Sharif University of Technology Dargi, Hassan (Author) ; Nemati, Ali (Supervisor)

Abstract

In this research, the additive effect of mullite and spinel nanoparticles on aluminum-based composites has been investigated in order to improve mechanical properties. Composite samples with synthesized mullite powder particles and spinel with the sizes of 80 nm and 200 microns respectively with values of (1.5, 3, 4.5) percent and spinel particles with values of (3, 6, 9) percent as phase The reinforcement, whose particles are preheated to 200°C and inside the aluminum foils, due to better wetting time with the background, was added to the background phase by the vortex casting method, and the temperature was cast at 750°C. . Then, in order to check the prepared powders and the...