杨金波
,
杨志刚
,
白秉哲
,
方鸿生
金属学报
利用原子力显微镜(AFM)对Fe--0.3C--3Mn--2Ni--2Si(质量分数, %)合金中315℃等温贝氏体相变的表面浮突效应及相应区域的微观组织进行了对比观察.结果表明, 伴随贝氏体相变的帐篷型表面浮突效应完全是新相长大过程中的形状应变所引起; 贝氏体铁素体最小结构单元的表面浮突为帐篷型, 不同于单倾型马氏体浮突, 不可能以切变方式形成, 它的两浮突角在8---100之间. 扩散台阶机制可以解释上述现象。
关键词:
贝氏体
,
surface relief
,
ferrite
,
structural unit
俞德刚
,
陈大军
,
郑经纮
,
何忆蓉
,
沈甫法
金属学报
低中碳合金钢的条状和片状贝氏体铁素体包含着集结成束的铁素体亚条,亚条由多个有规则形状的铁素体细块组成,它是贝氏体铁素体的均匀切变长大的相变基元,其中无碳化物析出。贝氏体θ-碳化物来源于α基元块的相界沉淀,或富化碳奥氏体的脱溶分解。 铁素体亚条束的基元群有单、双向两种排列方式。单面表面浮雕是单向排列基元群的基元块单向均匀切变应变的累积所构成的;帐篷式的双面表面浮雕是双向排列的二组基元群的基元块相向均匀切变应变的累积所引起的,当二组基元群的基元块向背均匀切变应变的累积便形成倒置帐篷式的双面表面浮雕。二组基元群的间界面显示为“中脊面”。
关键词:
低中碳合金钢
,
bainite
,
ferrite
,
phase transformation unit
,
surface relief
吴静
,
刘新新
,
顾新福
,
戴付志
,
杨海涛
,
张文征
金属学报
表面浮凸伴随着丰富的相变晶体学信息,对板条马氏体表面浮凸的形状应变进行研究,可以获得相变过程中累积的长程应变场的晶体学信息,进而实现对相变应变场和界面结构的准确描述.本文对Fe-20.2Ni-5.5Mn(质量分数,%)合金中板条马氏体表面浮凸进行系统地定量表征,并借鉴双面金相位移合成法合成单面样品浮凸的位移矢量.采用原子力显微镜(AFM)结合电子背散射衍射(EBSD)观察到该合金中板条马氏体浮凸呈帐篷型.EBSD统计分析显示板条马氏体与基体之间位向关系接近K-S关系,它们的惯习面接近(111)_f,合成的位移矢量分散在[121]_f附近,最大切变角为27.49°.实验中采用AFM观察到的浮凸角为22.41°,小于合成得到的最大切变角,这可能由于惯习面不垂直于自由表面所致.
关键词:
相变晶体学
,
板条马氏体
,
表面浮凸
,
形状应变
X.P.Lin
,
Y.Dong
,
X.M.Cao
,
Y.Zhang
,
N.J.Gu
,
X.L.Ma
金属学报(英文版)
Habit plane rotation of lath martensite transformation in Fe-Ni-Mn alloy was predicted by means of Displacement Vector Theory. Its surface relief effect was observed and a math model for the quantitative analysis of habit plane rotation of lath martensite transformation was established by means of atomic force microscopy (AFM). The experiment showed that the largest rotation of habit plane of lath martensite transformation predicted by means of Displacement Vector Theory is 13.50°, and it's incompatible with the concept of invariant plane strain (IPS); surface relief of lath martensite revealed no character of IPS, i.e. it exhibited irregular “N”-shaped “surface relief packet”, and “surface relief packet” was composed of layers of several small surface reliefs, the AFM quantitative analysis of habit plane rotation of lath martensite transformation was 11.11°, which was in agreement with the prediction of Displacement Vector Theory (13.50°) and it firmly confirmed the habit plane rotation of lath martensite transformation and the correctness of Displacement Vector Theory.
关键词:
atomic force microscope (AFM)
,
null
,
null
