V An experimental study on the simultaneous effect of nanoparticles and Cyclic Extrusion- Expansion (CEE) on the mechanical properties of magnesium alloy

V An experimental study on the simultaneous effect of nanoparticles and Cyclic Extrusion- Expansion (CEE) on the mechanical properties of magnesium alloy


V An experimental study on the simultaneous effect of nanoparticles and Cyclic Extrusion- Expansion (CEE) on the mechanical properties of magnesium alloy

نوع: Type: thesis

مقطع: Segment: masters

عنوان: Title: V An experimental study on the simultaneous effect of nanoparticles and Cyclic Extrusion- Expansion (CEE) on the mechanical properties of magnesium alloy

ارائه دهنده: Provider: Faraj Sadeghi

اساتید راهنما: Supervisors: Dr. Faramarz Fereshteh-Saniee

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Dr.Abas Fadaei - Dr.Hashem Mazaheri

زمان و تاریخ ارائه: Time and date of presentation: November, 2020

مکان ارائه: Place of presentation:

چکیده: Abstract: In recent years, many studies have been performed on the mechanical behavior and microstructure of magnesium and its alloys due to special properties such as low density, high strength to weight ratio, high machinability and good thermal conductivity. These studies have led to an increase in the use of magnesium alloys. However, the mechanical properties of magnesium are not sufficient for some engineering applications, which can be addressed by adding nanoparticles. In the present study, the effect of adding nanoparticles on the mechanical properties of the sample obtained from the expansion extrusion (CEE) process, which is a new method among the methods of severe plastic deformation, has been practically investigated. For this purpose, after selecting 20 nm alumina nanoparticles and AM60 alloy as the base metal, in addition to the sample without nanoparticle, AL2O3/AM60 metal base with three different weight percentages (0.5, 1, 1.5) was made. Then, using the cyclic expansion extrusion process, high strains were applied to the casting samples during three different stages at 250 ℃ and 2 mm/min strain rate. After the extrusion process, the results of hardness, metallography and compression tests at room temperature were examined. In this study, the Bulge Correction Factor (FCB) was used to correct the result of the compression test. The result is a reduction in grain size and an increase in hardness and compressive strength by increasing the weight percentage of nanoparticles in casting samples. The results of extruded samples also showed a decrease in the effect of CEE process after one step by increasing the weight percentage of nanoparticles. In the force-displacement curves, the nanoparticle compression test and CEE process increased the compressive strength and decreased the displacement during the first two stages. But the CEE process in the third stage increased the ductility. Key Words: Expansion extrusion, Severe plastic deformation, Magnesium AM60, Mechanical properties, Microstructure, Al2O3 nanoparticles

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