Sharif Digital Repository

The study on new rheoforming technologies of semi-solid alloys has recently been one main subject interesting many researchers and industrials, and so many new methods about preparing semi-solid alloy slurry and rheoforming process have been suggested. Among more than 20 proposed methods, only MHD (Magneto Hydro Dynamics) and EMS (electromagnetic stirring) methods has been industrialized. In this research, the semi-solid slurry of A356 aluminum alloy was fabricated by electromagnetic stirrer under different conditions of stirring current, stirring time and pouring temperatures. Then the semi-solid slurry prepared in optimum conditions was injected into a step-die cavity by a drop device and... 

In the last decade, magnesium alloy has been developed owing to it’s low density, high specific strength, good castability and damping property. AZ91 alloy is proved to be the most common and most important magnesium casting alloy. It is shown that, rheocasting process is a proper way which increases the mechanical properties of the products. Since 28 years, so many new methods for preparing Semi-Solid alloy slurry and rheoforming process have been suggested. Electromagnetic Stirring ( EMS ) method was used for making globular structures. In this research, the semi-solid slurry of AZ91 magnesium alloy was prepared by electromagnetic stirrer under different conditions of stirring current and... 

Al-4.5% Cu alloy, an age-hardenable alloy, is an important alloy in industry due to such unique characteristics as high strength-to-weight ratio and considerable strength at elevated temperatures. In this study, the aim was to evaluate the combined effect of cooling rate and heat treatment on an A206 alloy having more impurities—especially iron—than the nominal specifications. To this end, the melt was poured in a five-step mold. Afterwards, each step was subjected to T4 and T6 treatments in order to study the changes compared to the as-cast samples. Ultimate tensile strength, yield strength, elongation, and grain size were determined by using tensile tests and optical microscopy,... 

Aluminum is the lightest industrial element after magnesium. As a result, aluminum alloys have many industrial usages because of their high specific strength. Semisolid casting is one of the processes that is capable of producing aluminum alloys with high mechanical properties. In this process, there are a wide variety of methods to prepare semisolid slurry, one of the best ways of which to produce globular structure is electromagnetic stirrer. In this research, the semisolid slurry of A356 aluminum alloy is fabricated by electromagnetic stirrer under different conditions of stirrer intensity current, stirring time and pouring temperature. Then the fabricated semisolid slurry is injected...