以微细Si粉为原料制备Mg-2Si合金的研究  

Preparation of Mg-2Si Alloys with Fine Si Powders as Raw Materials

作　　者：刘志文[1] 严红革[1] 朱素琴[1] 唐治[2] 陈吉华[1] 

机构地区：[1]湖南大学材料科学与工程学院 [2]北京科技大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2010年第4期376-379,共4页Special Casting & Nonferrous Alloys

基　　金：教育部新世纪优秀人才支持计划资助项目(NCET-06-0701);高等学校博士学科点专项科研基金资助项目(20070532087)

摘　　要：研究了以微细Si粉作为原料制备的Mg-2Si合金的组织及力学性能。结果表明,当Si以微细粉末(≤48μm)的形式在700℃加入到熔体中并保温3min后浇注,可以获得较为细小的合金组织,其中初生Mg2Si相呈细小的多面体(≤10μm),共晶Mg2Si杆长度在100μm以下。当Si以微细粉末的方式加入时,合金熔体中出现大量的富Si区域和贫Si区域,从而在凝固过程中析出细小而数量较多的初生α-Mg相和初生Mg2Si相。二者构成细密的骨架,分割剩余熔体,抑制共晶组织的生长,从而明显提高合金的力学性能。Microstructure and mechanical properties of the Mg-2Si alloys prepared with fine Si powders as the raw materials were investigated by OM (optical microscope), SEM (scanning electron microscope), XRD (X-ray diffraction) and tensile testing. The results show that the primary Mg2Si particles are characterized by the fine polyhedral shape with size less than 10μm and length of eutectic Mg2Si rods is less than 100μm after fine silicon powders with size less than 48μm is added into the aluminum melt at 700℃ and holding for 3 min. Amounts of fine primary α-Mg phase and primary Mg2Si phase are precipitated from the aluminum melt during solidification as a result of many Si rich regions and Si-poor regions occurred in the melt with addition of Si powders, forming compact skeleton frame to divide the residual melt and restrain the growth of the eutectics, which is responsible for the improvement of mechanical properties.

关 键 词：Mg-2Si合金 微细Si粉 初生Mg2Si相 共晶组织 

分 类 号：TG292[金属学及工艺—铸造] TG146.22[一般工业技术—材料科学与工程]