D0I:10.13374/j.issn1001-053x.1989.06.031 北京科技大学学报 第11卷第6期 Vol.11 No.6 1989年11月 Journal of University of Science and Technology Beijing Nov.1989 The Microstructure of Graphite Spherulites in Cast Iron' Miao Baihe(苗柏和)**，Fang Keming(方克明)* 、 ABSTRACT:The microstructure of graphite spherulites (G.S.)in Ce addition ductile cast iron was carried out using transmission electron microscopy (TEM) techniques.The structral characterization of the graphites is as following:there are platelets growing along the periphery as well as fan-like structure formed from platelet aggregates in the diameter section of spherulite,in which most of the platelets are with sizes ranging from several to tens nm in radial;the [001] direction of the platelets would have a tend to parallel to radial of the G.S. and meanwhile,they also a small misorientation deviated from the radial among the platelets each other.It shows that the anisotropy of graphites has been restrained by adding Ce element in cast iron and the structural characterization of the G.S.is consistent with the Double's model of the conical helixes formed in helical growing and branching. KEY WORDS:cast iron,graphite spherulite,microstructure The optical microscopy and scanning electron microscopy (SEM)have been extensively used to invcstigate the morphologies and growth mechanism of gra- phites in cast irons before and at the same time many growing models of G.S. 1 were proposed -1,but there are only a few studies on the structure of G.S. using TEM techniquest.Therefore,there was little possibility to review the theoretical models with the TEM experimental results. Recently,it was because of use of ion thinning instrument and a new know- how I in sample preparation that it is possible to perfcrm TEM analysis on the microstructure and Ce distribution in single G.S.I8]And thus it can further deal with the effect of Ce addition on the structure of graphites as well as the growing mechanism of G.S. Manuscript Received April 4,1989 ..Dept.of Material Science and Enginecring ···Dept,of Physical--Chemistry 581第 卷 第 期 北 京 科 技 大 学 学 报 乃 。 后 年 月 入 苗 柏 和 ， 俐 方 克明 、 、 · 住 一 ， 〔 〕 一 ， 习 。 。 ， ， ， 、 、 从 · · ‘ 一 ， · · ’ ’ 〕 ， · ， 任 丁 · · 〔 · ， ， · · ， · 一 DOI ：10．13374／j ．issn1001－053x．1989．06．031