Papers by Keyword: Eutectic Silicon

Abstract: Hypereutectic Al-15Si (wt pct) alloys with various content of rare earth Ce were prepared by conventional casting technique. The influence of the primary silicon phase and eutectic silicon on the solidification process of hypereutectic Al-15Si alloys with the addition of Ce is presented. The microstructures were examined with conventional light microscope and scanning electron microscope. The simultaneous refinement of both the primary and the eutectic silicon particles wasntachieved with Ce additions. The results showed that the addition of cerium doesnt cause to refinement of the primary silicon grains, while cerium is caused to stress on concentration regions.The results showed that the addingthe cerium had a negative influence on the alloys tensile strength.

Abstract: Alumina/Al-Si alloy composites were manufactured by squeeze casting. The morphology of eutectic Si in the composite was observed on scanning electronic microscope, and the modified mechanism of the eutectic Si in the composite was approached. The alumina fiber in the composite could trigger twin during the growth of Al-Si eutectic and lead to modification of the eutectic Si near the fiber.

Abstract: The structural control of A356 alloy, which was not studied among various electromagnetic processing of materials, was considered applying the alternating current and direct current magnetic flux density. The main aim of the present study is to investigate the effects of electromagnetic vibration on the macro and microstructure of A356 alloy in order to develop a new process of structural control in A356 alloy. When the electromagnetic vibration is conducted for changing the shape of primary aluminum, at low frequency (≤60Hz), the shape of dendrite is changed speroidal shape. When the electromagnetic vibration is conducted for changing the shape of eutectic silicon, a morphological change of the eutectic silicon from coarse platelet flakes to fine fiber shape is observed with EMV (Electro Magnetic Vibration) process at high frequency (≥500Hz).

Abstract: The structural control of Al-Si alloy, which was not studied among various electromagnetic processing of materials, was considered applying the alternating current and direct current magnetic flux density. The main aim of the present study is to investigate the effects of electromagnetic vibration on the macro and microstructure of Al-Si alloy in order to develop a new process of structural control in Al-Si alloy. When the electromagnetic vibration is conducted for changing the shape of primary aluminum, at low frequency (≤ 60Hz), the shape of dendrite is changed speroidal shape. When the electromagnetic vibration is conducted for changing the shape of eutectic silicon, the fact that a morphological change of the eutectic silicon from coarse platelet flakes to fine fiber shape is observed with EMV (Electro Magnetic Vibration) process at high frequency(≥ 500Hz).