CAJ | 학술논문

采用光学显微镜、扫描电镜及电子背散射衍射技术研究亚共晶Al-Si合金共晶团的形核与生长.通过揭示共晶团和结晶位向的分析发现:在同一个共晶团中Si相和Al相都不是单晶体,而是由不同位向的小“晶粒”构成的.提出不能依据共晶团中Al相与周围初生枝晶Al相的位向关系来确定共晶的形核模式的建议.然而,初生枝晶铝相的演化显著影响随后的共晶形核与生长.涉及的杂质元素使共晶Si的形貌由粗大的片状转变成细小的纤维状的变质行为,可能与共晶的形核无关.
채용광학현미경、소묘전경급전자배산사연사기술연구아공정Al-Si합금공정단적형핵여생장.통과게시공정단화결정위향적분석발현:재동일개공정단중Si상화Al상도불시단정체,이시유불동위향적소“정립”구성적.제출불능의거공정단중Al상여주위초생지정Al상적위향관계래학정공정적형핵모식적건의.연이,초생지정려상적연화현저영향수후적공정형핵여생장.섭급적잡질원소사공정Si적형모유조대적편상전변성세소적섬유상적변질행위,가능여공정적형핵무관.
The nucleation and growth of eutectic cell in hypoeutectic Al-Si alloy was investigated using optical microscopy and scanning electron microscopy equipped with electron backscattering diffraction (EBSD).By revealing the eutectic cells and analyzing the crystallographic orientation,it was found that both the eutectic Si and Al phases in an eutectic cell were not single crystal,reprsenting an eutectic cell consisting of small ‘grains’.It is also suggested that the eutectic nucleation mode can not be determined based on the crystallographic orientation between eutectic Al phases and the neighboring primary dendrite Al phases.However,the evolution of primary dendrite Al phases affects remarkably the following nucleation and growth of eutectic cell.The coarse flake-fine fibrous transition of eutectic Si morphology involved in impurity elements modification may be independent of eutectic nucleation.