【摘要】 高硅铝合金中加入Bi形成Al-Si-Bi多元合金,具有偏晶转变的结晶特点。显微分析表明,由于Bi在合金中的不溶性,较大的密度,除少量Bi出现局部偏聚外大部分Bi在基体中以高度弥散态分布。Bi对共晶Al-Si合金中的初晶硅和(α+β)共晶体有较好的细化作用。含Si量的变化影响Bi相的形貌和对组织的细化效果。更多还原

【Abstract】 Bi is added into high silica Al-alloy to form multicomponent Al-Si Bi whose crystallization has the character of monotectic transition. Micro-analysis indicates that the most of Bi is highly dispersecl in the matrix, but quite a few Bi is not uniform because Bi has insolubility and high density in matris. Bi can refine the primary silica grain and(α+β)eutectic grain in eutectic Al- Si alloy, in the same time the change of silica content can influence the appearance of Bi phase and refining result to the microstructure.更多还原