Al-Si合金中共晶硅生长形态的研究

A Study on the Grown Morphologies of Eutectoid Silicon in Al-Si Alloys

用氮气雾化法制取了Ａｌ-１２．５４％Ｓｉ合金微粒并进行７００℃重熔处理，对加Ｓｒ变质的Ａｌ-１３．２３％Ｓｉ合金熔体进行了直流电处理。用扫描和透射电镜研究了不同处理条件对Ａｌ-Ｓｉ合金中共晶硅生长形态的影响。结果表明，快速凝固的合金微粒与重熔处理试样中共晶硅呈球状和条状；加Ｓｒ变质的共晶硅为弯扭的纤维状，直流电熔体处理后，共晶硅为圆球状，其颗粒尺寸为５０～２００ｎｍ．

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.