CAJ | 학술논문

研究Sr对过共晶Mg-4％Si(质量分数)合金中Mg2Si相的变质作用与机理.Mg-4％Si合金中存在多面体形初生Mg2Si相与汉字状共晶Mg2Si相.添加Al-10％Sr可以明显细化初生Mg2Si相,同时可以将共晶Mg2Si相由汉字状变质为多面体状或者纤维状.对初生Mg2Si相的细化作用主要是由凝固过程中含Sr颗粒的异质形核作用引起的,而对共晶Mg2Si相的变质作用是由在凝固过程中熔体中的Sr原子在Mg2Si晶体生长表面富集,从而改变了其生长优势所致的.
연구Sr대과공정Mg-4％Si(질량분수)합금중Mg2Si상적변질작용여궤리.Mg-4％Si합금중존재다면체형초생Mg2Si상여한자상공정Mg2Si상.첨가Al-10％Sr가이명현세화초생Mg2Si상,동시가이장공정Mg2Si상유한자상변질위다면체상혹자섬유상.대초생Mg2Si상적세화작용주요시유응고과정중함Sr과립적이질형핵작용인기적,이대공정Mg2Si상적변질작용시유재응고과정중용체중적Sr원자재Mg2Si정체생장표면부집,종이개변료기생장우세소치적.
A modification of Mg2Si in the hypereutectic Mg-4％Si alloy(mass fraction)with Sr was investigated.Two types of Mg2Si in the alloys were found:polygonal primary Mg2Si and Chinese script type eutectic Mg2Si.Adding Al-10％ Sr master alloy to the Mg-4％Si alloy clearly reduced the average size of primary Mg2Si and changed the morphology of eutectic Mg2Si from Chinese script type to polyhedral or fine fibre shape.The refinement of primary Mg2Si is mainly attributed to the heterogeneous nucleation mechanism induced by the Sr-rich particles.The modification of eutectic Mg2Si results from the dissolved Sr,which alters the preferred growth manner of the eutectic.