期刊文献+

La、Ce对Al-24Si合金中Si相生长的作用 被引量:3

Effects of La-Ce Mischmetal on Growth of Si Phase in Al-24Si Alloy
下载PDF
导出
摘要 研究了La、Ce混合稀土对过共晶Al-24Si合金中初生Si和共晶Si形态的影响。采用不同的腐蚀、萃取方法,得到未变质和La、Ce混合稀土变质的过共晶Al-24Si合金中初生Si和共晶Si相完整的立体形貌,借助扫描电镜和能谱仪对其进行形貌观察和物相分析。结果表明,在Al-24Si合金结晶过程中,La、Ce通过在Si/Al界面前沿合金液中的富集作用,一方面抑制了Si相的长大,另一方面通过成分过冷影响Si相的长大方式,使其以非小平面即粗糙界面方式长大,改变初生Si和共晶Si相的形貌;对合金中形成的稀土化合物进行能谱分析表明,化合物中Si的摩尔分数较高,证明在稀土化合物的形成过程中部分消耗了Si原子,使初生Si和共晶Si长大时组织中Si含量减少,有效阻碍了初生Si和共晶Si的长大。 Effects of La-Ce mischmetal on primary Si and eutectic Si in hypereutectic Al-24Si alloy were investigated. The stereo-morphologies of primary Si and eutectic Si in un-modified and in La-Ce modified alloys were obtained by different etching and extracting methods. Microstructure and phase constituent of the alloy were observed by SEM (scanning electron microscope) and XRD (X-ray diffraction). The results reveal that,on the one hand,the La and Ce enrichment in the liquid alloy of Si/Al interface front can inhibit the growth of Si phase,on the other hand,it causes the constitutional supercooling,during the crystallization process of Al-24Si alloy,which makes the Si phase grow in non-faceted mode or so-called rough interface mode,resulting in the morphology change of primary Si phase and eutectic phase. Composition analysis of rare earth compounds in Al-24Si alloy shows that atomic percentage of Si is higher,showing the partly consumption of Si atoms during RE compound generation process,which results in the decrease of Si content in primary Si and eutectic Si phase to effectively restrain the growth of primary Si and eutectic Si phases.
出处 《特种铸造及有色合金》 CAS CSCD 北大核心 2010年第6期575-578,共4页 Special Casting & Nonferrous Alloys
关键词 La、Ce混合稀土 Al-24Si合金 Si相生长 La and Ce Mischmetal,Al-24Si Alloy,Growth of Si Phase
  • 引文网络
  • 相关文献

参考文献9

二级参考文献78

共引文献227

同被引文献41

引证文献3

二级引证文献16

;
使用帮助 返回顶部