【摘要】 研究了钡、磷及钡磷复台变质对过共晶铝硅合金初晶硅的细化作用，发现钡变质可细化初晶硅的尺寸，同时使硅晶体由板块状改变为树枝状；磷变质可明显细化初晶硅，但对其形状因子改变不大；但磷复合变质综合了二者的优势。硅晶体表面有钡或钡的化合物的吸附，认为吸附抑制机制是钡变质的实质。更多还原

【Abstract】 The refinement of primary silicon in Al-Si hypereutectic alloys rnodified by barium,phosphorus orboth of them has been studied. It is found that barium refines the primary siIicon and changes its morphology from ablock crystallographic form to a dentritic one. Phosphorus has better refinement of primary silicon but has little effecton the morphology. The combination of barium and phosphorus makes much better refinement of the primary silicon.And it is observed on the surface of primary silicon that there exists much mapping of barium or bari-chemicals,show-ing that tbe growth of primary si1icon has been largely hindered.更多还原