石章智张文征
金属学报
doi:10.3724/SP.J.1037.2010.00323
以相变晶体学为主要原则对Mg-Sn-X合金进行优化设计. 在对现有镁合金系统充分调研的基础上, 根据Mg基体与析出相的相变晶体学匹配关系, 提出2条相变晶体学判据来判断可能沿Mg基体[0001]α方向择优生长的析出相. 根据这2条相变晶体学判据结合相图分析推测在Mg-Sn-Mn系统中可能得到沿Mg基体[0001]α方向择优生长的β-Mn析出相. 对Mg-7.5Sn-2.2Mn(质量分数, %)合金时效组织的TEM研究证实了上述判断. 研究结果表明, β-Mn析出相呈棒状, 长轴沿Mg基体[0001]α方向, 它与Mg基体的位向关系(OR)是: [0001]α///[211]β-Mn, [0110]α///[011]β-Mn, [2110]α//[111]β-Mn.
关键词:
镁合金设计
,
crystallography of phase transformation
,
morphology of precipitates
,
orientation relationship
崔桂彬郭晖杨善武贺信莱
金属学报
采用电子背散射衍射 (EBSD) 研究了低碳Fe--C--Mn--Si钢中晶界铁素体/原奥氏体界面对贝氏体形核的影响. 通过两阶段等温热 处理, 获得了晶界铁素体和贝氏体的混合组织. 结合金相观察和取向测量, 发现晶界铁素体与贝氏铁素体之间的界面分为两种, 一种界面不清晰, 一种界面清晰. 分析表明, 在晶界铁素体/贝氏体界面不清晰一侧, 晶界铁素体与原奥氏体保持取向关系, 贝氏体在这类界面形 核生长, 且取向与晶界铁素体保持一致; 在晶界铁素体/贝氏体界面清晰一侧, 晶界铁素体与原奥氏体无取向关系, 且贝氏体与晶界铁素体之间取向差较大.
关键词:
低碳钢
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grain boundary ferrite
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bainite
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interface
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nucleation
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orientation relationship
Z.Q. Sheng and H. Xiao(National Key Laboratory for Nuclear Fuel and Material
,
Nuclear Power Institute of China
,
Chengdu 610041
,
China)Manuscript received in revised form 16 October 1998)
金属学报(英文版)
By means of TEM technique the orientation relationships of cementite, precipitated from islands of granular bainite during tempering, with ferrite have been objerved. By calculating the eigenvalue and eigenvector of transformation matrix, Isaichev relationship has been analyzed. The results indicate that Isaichev relationship indeed is the sum of Kungumov-Sachs relationship and Pitsch relationship, so the viempoint that the cementite with Isaichev relationship precipitates from austenite, instead of ferrite,is confirmed. Moreoven the matrix calculation shows that three reported orientation relationships among austenite, ferrite and cementite in pearlitic transformation cannot be simultaneously valid.
关键词:
orientation relationship
,
null
LI Douxing PING Dehai NING Xiaoguang YE Hengqiang Laboratory of Atomic Imaging of Solids
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang.China Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The characteristic of interface depending on the atomic structure exerts an inportant,and sometime controlling,influence on performance of the interacial materials. The present paper reviews the main studies on fine structure of both the materials inter- faces and interfacial reaction products in semiconductor uperlattice,metal multilayer ceram- ics and composite materials by mean of selected area electron doffraction patterns and high resolution electron microscopy. The following features of interfaces are reviewed:the orientation relationships;the char- acteristic of steps,facets and ronghness of interfaces;atomic bonding across the interface;the degree of coherency,the structure of misfit dislocations and elastic relaxations at the inter- faces:the presence of defects at the onterfaces:the structure of the interfacial reaction prod- ucts as well as the reaction kinetics and reaetion mechanism.
关键词:
fine structure of the interfaces
,
null
,
null
,
null
LIU Qingquan ZHANG Xiumu TENG Huayuan WANG Yikang Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China
材料科学技术（英）
The investigation on lath martensitic transfor- mation has been carried out for 24SiMnNi2CrMoA steel using transmission electron microscopy (TEM) and X-ray diffraction.The austenite and martensite in the alloy adopt the intermediate orientation relationship between Kurdjumov-Sachs and Nishiyama.The adjacent laths in a packet are small-angle related or twin-related.The retained austenites which accommodate shape deformation of martensites appear commonly between adjacent laths.High Si content increases the volume fraction of retained austenites and its stability.The excellent combination of high strength and toughness of this steel is attributed to its fine martensite laths mingled with more than 5% continuous retained austenite films.
关键词:
martensitic transformation
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null
,
null
,
null
丁辉
,
雷静
,
束国刚
,
万强茂
材料热处理学报
利用透射电镜研究了质子辐照对反应堆压力容器钢A508-3钢显微组织形态的影响,基于拍摄的铁素体与渗碳体的复合衍射花样,采用矩阵分析法研究了质子辐照前后试样铁素体与渗碳体之间的取向关系.结果表明,辐照前后A508-3钢的铁素体板条宽度和碳化物的尺寸、体积分数及分布没有发生明显变化.A508-3钢辐照至0.271 dpa时产生了分布较为均匀的位错环,位错环平均直径约为4.6 nm,数量密度约为2.7 ×1022m-3.在未辐照试样观察到铁素体和渗碳体的取向关系符合Bagaryatskii关系,而0.216 dpa和0.271 dpa辐照试样中观察到铁素体和渗碳体之间出现了3种新的取向关系.这3种新的取向关系的来源及对力学性能的影响值得深入研究.
关键词:
质子辐照
,
组织形态
,
矩阵分析法
,
取向关系
