In this paper

the particles of Al-Si alloy with 12.54 percent of silicon were producedby nitrogen atomization.These particles were heated to 700℃ and re-melted.The molten of Al-Sialloy with 13.23 percent of silicon and modified with Sr has been treated with direct current. Theeffect of different processing condition on the morphologies of eutectoid silicon in Al-St alloy wasinvestigated with TEM and SEM.Results show that in samples which were produced using atomized particles or re-melting treatment

the morphologies of eutectoid silicon were spheroidal or ribbon like

while those modified with Sr

the eutectoid silicon presented some curved fibrous shape.After direct current treatment

the morphologies of eutectoid silicon could be changed intospheroidal.Their particle size was within 50-200 urn.