بررسي تاثير استرانسيم بر ريزساختار كامپوزيتهاي ريختگي A356 -B4C

The Effect of Strontium on the Microstructure of A356-%10B4C Cast Composite

The present study was undertaken to investigate the effect of strontium on the microstructure and silicon eutectic morphology of A356-%10B4C cast composites. The composite ingots were made by stir casting process and then strontium was added with different contents (0.05%, 0.1%, 0.2%, 0.5% and 1%). Optical microscopy (OM) and scanning electron microscopy (SEM) equipped with an EDX have been utilized for the characterization of B4C-reinforced A356 matrix composites. The obtained results has shown that the addition of strontium up to 0.2% has not any considerable effect on silicon eutectic morphology but adding more strontium contents (0.5% & 1%) contributes to complete modification of silicon crystals. It seems that strong negative interaction between strontium and A356- B4C has taken placed and due to this interaction, modification of silicon crystals was limited.