EBSD技术及其在取向硅钢研究中的作用

电子背散射衍射EBSD是一种用来分析多晶材料显微结构、晶粒取向和微观织构的扫描电镜新技术。本文结合基本原理介绍了EBSD技术在取向硅钢研究中的作用。     

EBSD分析技术在ECAP变形材料研究中的应用

简述了电子背散射衍射(EBSD)技术的基本原理和试验分析方法,并结合实例说明EBSD技术在等径弯曲通道变形(ECAP)材料取向、晶界研究等方面的应用。     

多晶纯钴退火组织中的孪晶转变规律研究

主要是结合X射线衍射(XRD)技术以及电子背散射衍射(EBSD)技术,对不同退火温度下的多晶纯钴的退火组织的变化规律展开研究。结果表明:残留的多晶纯钴面心立方(fcc)结构的晶粒内部在退火过程中形成了∑3孪晶界,而且具有这种特征的晶粒数量随退火温度改变不大,基本趋于稳定;同时,具有密排六方(hcp)结构的晶粒内部在退火过程中形成大量的71.4°/1120特殊晶界。通过分析得知这种晶界形成的原因与fcc结构的晶粒中的∑3晶界的形成原因不同,是由fcc→hcp马氏体相变导致,即为相变孪晶。     

一种5083铝合金中晶界面热轧织构的研究

通过电子背散射衍射技术,测定了一种5083铝合金中的热轧织构。结果表明：在结构中的不同位置,织构组分呈现非均匀发展的特点,特别地,晶界面亦呈现取向织构。在样品的中心位置,晶界面趋向于{111}取向,且其数量高出随机晶界50%;同时,在样品的边缘位置,晶界面趋向于{110}与{112} 取向,且其数量高出随机晶界28%。更具体地,小角和大角晶界中均呈现这种晶界面的各向异性分布。     

纯铜直管组织与织构对表面缺陷成形影响

采用光学显微技术及电子背散射衍射(EBSD)技术分别对弯曲发生缺陷和不发生缺陷前的纯铜直管的显微组织进行观察和表征。结果表明:管材组织呈纤维状结构并与管材轴向平行,材料内形成强烈的织构,晶粒取向均以111和100为主,而孪晶界主要出现在111织构中。认为导致直管褶皱、裂纹产生的可能原因是大量的111织构会形成更多的孪晶。     

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 利用电子背散射衍射、扫描电镜和X射线衍射技术研究了CVD自支撑金刚石薄膜的孪晶组织形貌、孪晶界和晶体取向差分布。研究表明,金刚石薄膜中存在一阶和二阶孪晶,不同的孪晶取向转变过程能形成不同的孪晶组织形貌,高频率的孪晶能对薄膜织构产生明显影响。     

贵金属超细丝材截面的EBSD与三维重构表征

贵金属超细丝材常用于精密电子功能器件的关键位置,但由于其加工成品尺寸微细传统技术无法准确表征超细丝材的微观精细结构.采用聚焦离子束-电子背散射衍射(FIB-EBSD)联用的超细丝材截面制样与表征方法,精确表征出了4种不同材质贵金属超细丝材的晶粒、取向、织构以及晶界等微观结构信息;而3D EBSD三维重构技术将微观结构分...     

Hi-B钢二次再结晶退火过程中未异常长大Goss晶粒晶界特征

采用中断法并结合电子背散射衍射(EBSD)技术,研究了Hi-B钢二次再结晶退火过程中大量未异常长大Goss取向晶粒的晶界特征。结果表明:未异常长大Goss取向晶粒的晶粒尺寸相较于基体晶粒和相邻晶粒并没有明显的差异性。同时未异常长大Goss取向晶粒与异常长大Goss取向晶粒周围的HE晶界和CSL晶界比例也没有明显的差异。在二次再结晶退火过程中,尺寸优势、HE晶界、CSL晶界和Goss取向偏离度都不能保证Goss取向晶粒发生异常长大。而随着退火温度的升高,Goss取向晶粒有逐渐向标准Goss晶粒取向靠拢的趋势。     

利用SEM-EBSP研究多晶体材料高温蠕变损伤组织的不均匀性

研究了多晶体材料在高温蠕变下的空洞出现位置和损伤特点,认为同一组织下空洞的出现及蠕变损伤的位置与晶粒尺寸有关系,晶粒尺寸小的部位易发生损伤。使用电子背散射衍射技术研究了不同损伤位置附近的亚结构形成情况,结合亚结构、晶界滑移、晶粒尺寸与材料变形协调性等材料变形特点,对蠕变损伤机理进行了探讨。     

电子背散射衍射技术在材料显微分析中的应用

介绍了电子背散射衍射的原理、装置的构造、分析方法及其应用。电子背散射系统（EBSD）与能谱（EDS）和扫描电镜一起工作可同时分析试样特定微区的形貌、成分和取向。当电子束逐点扫描分析时,还可获得一种全新的图象即晶体取向分布图,从而获取微区的形貌、成分及成分的定量分布图。以纯铁为例,对该技术进行了验证。     

电子背散射衍射（EBSD）及其在材料研究中的应用

论述了电子背散射衍射（EBSD）的形成原理、花样包含的物理意义，并给出了EBSD在测定晶体取向、织构、取向关系、物相鉴定、应变分布、晶格常数及晶界性质研究等方面的应用实例。     

Microstructure and Orientation Evolution of Unidirectional Solidification Pure Copper during ECAP

Experiment were conducted to unidirectional solidification pure copper during ECAP by route C, the samples were investigated by XRD and EBSD. The results shown that the effect of original microstructure on the subgrains orientation decrease with the increasing of strain. At low strain, in the column grain interiors first formed a band structure that the orientation quite different with the matrix. With the strain increasing, the boundaries of the band structure expanding towards to two sides, gradually part...     

钢中珠光体球团尺寸的EBSD表征技术

借助光学显微镜和扫描电镜等研究了珠光体球团的表征方法,从阻止裂纹扩展的有效性出发,选择内部取向接近、外部取向差较大的球团簇作为评价珠光体球团尺寸的指标。结果表明,珠光体中铁素体的取向分布与球团吻合,即铁素体的大角度晶界就是球团(簇)界,所以可以通过表征铁素体的晶粒尺寸来评价珠光体球团尺寸。该方法的关键点在于晶界如何定义和样品如何制备。从对EBSD法的可行性分析可知,以15°作为晶内最大取向差来划分珠光体球团。对于珠光体钢,电解抛光法更适用于珠光体中渗碳体片层较宽的样品,而对于珠光体中渗碳体片层过窄的情况更适合选用离子抛光法。      

电子背散射衍射的制样方法和影响花样质量的因素

概述了电子背散射衍射(EBSD)原理.EBSD试样的制备质量很大程度上决定着EBSD测试的可行性和花样的质量.介绍了各种抛光方法的优缺点,包括机械抛光、化学抛光、电解抛光和离子束处理等.总结了影响EBSD花样质量的因素,主要包括样品的状态、电镜参数的设置和数据获取软件参数的设置等.研究对于EBSD技术的初学者具有很好的...     

Hot deformation behavior of a Fe3Al-binary alloy in the A2 and B2-order regimes

A binary Fe₃Al alloy is investigated with respect to hot deformation behavior and microstructural as well as microtextural modifications. Applying the hot deformation simulator (WUMSI) to hot rolling conditions in the A2 and B2-order regimes in combination with data analysis, significant changes in deformation behavior are identified. These conditions are selected for performing hot rolling experiments. The differences in microstructure are investigated. On the basis of microtexture investigations by means of electron backscatter diffraction (EBSD) differences concerning orientation gradients and sub-grain structures are found. A model of combined order-related and non-order related effects is proposed explaining the observed material behavior. The information gained is the basis for the optimization of the thermomechanical treatment to produce ductile Fe₃Al sheet material.     

Recrystallization behavior of high purity aluminum at 300 °C

The recrystaliization behavior of 98.5% cold rolled high purity aluminum foils annealed at 300 °C was investigated, and the evolution of the microstructures was followed by electron back scattered diffraction(EBSD). The results show that the recrystaliization process of the high purity aluminum foils at 300 °C is a mixture of discontinuous- and continuous-recrystallization. The orientations of the recrystaliization nuclei include not only the cube orientation, but also other orientations such as some near deformation texture components which are the results of strong recovery process. However, such continuously recrystallized grains are usually associated with relatively high free energy, so they would be consumed by the discontinuously-recrystallized grains (cube-oriented grains) in subsequent annealing. On the other hand, the pattern quality index of recrystallized grains shows dependence on the crystal orientation which might introduce some errors into evaluating volume fraction of recrystaliization by integrating pattern quality index of EBSD.     

Constraint-dependent twin variant distribution in Ni2MnGa single crystal,polycrystals and thin film: An EBSD study

The capability of showing large magnetically induced strains (MFIS) up to ～10% has attracted considerable research interest to magnetic shape memory (MSM) alloys. The prototype MSM alloy is the ternary Ni₂MnGa. In this work, a comprehensive study of the local unit cell orientation distribution on single crystalline, polycrystalline and epitaxial thin film of martensitic Ni₂MnGa is conducted by electron backscattering diffraction (EBSD). By EBSD, the constraint-dependent twin variant distribution, the corresponding stresses and the three-dimensional orientation of twin planes will be investigated. In polycrystals, the differentiation between twin and grain boundaries as well as proof of twin boundary motion is shown. From the knowledge of the local unit cell orientation at surfaces, it is possible to explain the magnetic domain configuration imaged by magnetic force microscopy.     

Deformation-induced austenite grain rotation and transformation in TRIP-assisted steel

Uniaxial straining experiments were performed on a rolled and annealed Si-alloyed TRIP (transformation-induced plasticity) steel sheet in order to assess the role of its microstructure on the mechanical stability of austenite grains with respect to martensitic transformation. The transformation behavior of individual metastable austenite grains was studied both at the surface and inside the bulk of the material using electron back-scattered diffraction (EBSD) and X-ray diffraction (XRD) by deforming the samples to different strain levels up to about 20%. A comparison of the XRD and EBSD results revealed that the retained austenite grains at the surface have a stronger tendency to transform than the austenite grains in the bulk of the material. The deformation-induced changes of individual austenite grains before and after straining were monitored with EBSD. Three different types of austenite grains can be distinguished that have different transformation behaviors: austenite grains at the grain boundaries between ferrite grains, twinned austenite grains, and embedded austenite grains that are completely surrounded by a single ferrite grain. It was found that twinned austenite grains and the austenite grains present at the grain boundaries between larger ferrite grains typically transform first, i.e. are less stable, in contrast to austenite grains that are completely embedded in a larger ferrite grain. In the latter case, straining leads to rotations of the harder austenite grain within the softer ferrite matrix before the austenite transforms into martensite. The analysis suggests that austenite grain rotation behavior is also a significant factor contributing to enhancement of the ductility.     

双相不锈钢中表面浮凸的测量与表征

在马氏体相变表面浮凸测量的传统手段基础上,发展了双面金相位移合成法;综合运用原子力显微术（AFM）和背散射电子衍射技术（EBSD）,对双相不锈钢中铁素体/奥氏体相变伴随的表面浮凸进行了系统的测量,包括奥氏体片条与铁素体基体的位向关系、惯习面取向以及产生浮凸的位移矢量和最大浮凸角,并用O线模型进行了初步的解释.