取向电工钢中Goss晶粒生长的取向环境

将以MnS为主要抑制剂的普通取向电工钢作为实验材料,检测并分析脱碳样品的宏观织构及脱碳和随后加热至925℃时样品的微观织构,统计分析了Goss与周围晶粒的取向差分布。根据取向差原理计算了脱碳样品主要织构组分内各取向晶粒的取向差环境。结果表明,取向电工钢脱碳退火后Goss晶粒与周围晶粒的取向差分布呈现大角度特征,主要取向差分布范围为30°-45°,而非Goss晶粒与周围晶粒的取向差分布则呈现更多小角度特征。二次再结晶后,Goss晶粒与周围晶粒的取向差分布仍然以大角度特征为主。     

超薄取向硅钢组织及织构与磁性能的关系

本工作旨在探讨超薄取向硅钢组织及织构与磁性能的关系,并从加工工艺角度揭示如何减少不利于磁性能的组织和织构的产生。利用电子背散射衍射(EBSD)技术和X射线衍射(XRD)技术对两种磁性能不同的商业超薄取向硅钢带材的显微组织和织构进行对比分析,结果发现,二者组织、织构差异均比较明显。磁性能差的带材样品的组织尺寸不一,均匀性较差,η线织构(〈100〉//RD)所占比例偏低,非η线取向晶粒所占比例高且晶粒尺寸大,其取向特征主要表现为{210}〈001〉、{411}〈148〉及{111}〈110〉。这些不利组织的产生可能与轧制、退火工艺控制不当有关。因此,晶粒尺寸及η线取向晶粒所占比例的不同是造成两种带材性能差异的主要原因,在高性能取向硅钢超薄带材制备过程中,应精准控制轧制、退火制度等相关工艺,以避免非η线取向晶粒形成、长大。     

退火张力对无取向硅钢再结晶织构和磁性能的影响

采用取向分布函数(ODF)分析了无取向电工钢冷轧板施加不同张力时再结晶退火后组织织构的变化。结果表明,随着退火张力的增加,再结晶晶粒尺寸逐渐增大,当退火张力为4 MPa时,晶粒平均直径达最大值75μm,且尺寸均匀,Goss织构和立方织构组分也增强,其铁损P_(1.5/50)降低到4.34 W·kg~(-1),同时磁感B50升至1.684T;当张力增加到6 MPa时,晶粒直径减小至40μm,{110}〈001〉和{001}〈100〉织构组分减弱,γ线织构组分明显增强,磁性能恶化。     

退火张力对无取向硅钢再结晶织构和磁性能的影响

采用取向分布函数(ODF)分析了无取向电工钢冷轧板施加不同张力时再结晶退火后组织织构的变化.结果表明,随着退火张力的增加,再结晶晶粒尺寸逐渐增大,当退火张力为4 MPa时,晶粒平均直径达最大值75 μm,且尺寸均匀,Cross织构和立方织构组分也增强,其铁损P1.5/50降低到4.34 W· kg-1,同时磁感Bs.升至1.684 T;当张力增加到6 MPa时,晶粒直径减小至40 μm,{110}<001>和{001}<100>织构组分减弱,γ线织构组分明显增强,磁性能恶化.     

Q235碳素钢应变强化相变中铁素体的取向特征

利用背散射电子衍射取向成像技术分析了在热模拟单向压缩条件下Q235碳素钢应变强化相变中铁素体晶粒的取向（差）变化特点。结果表明，奥氏体的状态影响应变诱导出的铁素体的取向，奥氏体的动态再结晶使应变诱导出的铁素体的取向随机分布，在铁素体的内部基本上没有小角晶界，随着形变温度的降低和应变量的增大，铁素体取向的择优性变强，铁素体内部的小角晶界增加，这是细小铁素体动态再结晶的表现，相变，形变以及铁素体的动态再结晶都影响＜111＞方向线织构的形成。     

镁合金AZ31高温形变机制的织构分析

利用X射线衍射和背散射电子衍射方法测定了镁合金AZ3l高温动态再结晶和超塑形变时的宏观和微观织构,分析了晶粒内部的形变机制.结果表明,在动态再结晶和超塑形变过程中,晶粒内部的滑移机制仍起重要作用,表现为再结晶晶粒出现择优取向以及一些晶粒可充分均匀形变成长条状.宏观织构的测定表明,具有不同初始织构的两类样品高温动态再结晶时,新晶粒有不同的取向择优过程,形成相似的织构;长条形变晶粒内部开动的滑移系也有一定的差异.分析了不同温度下相同的织构对应的不同塑变机理取向成像分析表明,基面织构取向的晶粒间总伴随着较高比例的小角晶界和30°(0001)的取向关系,这是六方结构的六次对称性限制了动态再结晶时(亚)晶粒间取向差的有效增大的缘故.     

低温热轧取向硅钢一次再结晶组织对磁性能的影响

采用EBSD技术对不同工艺处理的低温热轧取向钢的尺寸、取向差、CSL等进行了分析，结果表明：当大角度晶界占优时，磁性能较好，采用快速加热工艺有助于增大角度晶界所占的比例，采用渗氮工艺能提高功所占百分比并增大晶粒尺寸：25～45。取向差的晶粒所占比例较大时，磁性能较好．相比重位点阵（CSL）理论，高能晶界理论（HE）更符合本试验结果．     

镁合金搅拌摩擦焊接头晶粒取向和织构分析

利用背散射电子衍射分析技术(EBSD)和取像显微分析技术(OIM),通过定量测量变形镁合金AZ80A搅拌摩擦焊搭接接头的焊核区晶粒取向和织构,探讨了搅拌摩擦焊焊核区形成的微观过程.结果表明:AZ80A合金在搅拌摩擦焊过程中,存在塑性变形和动态再结晶两种微观过程,导致焊核区所形成的晶粒织构密度不强、取向呈多样化的趋势;晶粒为再结晶细晶粒;在焊核区,变形织构{1,-1,0,4}<1,0,-1,0>略偏离板法向20°,且随板厚方向向下越来越强,同时再结晶取向越来越多;焊核区晶粒继承了母材中的{1,-1,0,4}<1,0,-1,0>变形织构,在焊核区所发生的动态再结晶含有一定程度的原位再结晶.     

单向轧制70/30黄铜的形变织构及形成模型

对70/30黄铜进行不同形变量的单向轧制,用三维取向分布函数分析这种有宏观统计不对称的形变织构。根据单向轧制的受力状态描述其形成模型。结果表明:单向轧制黄铜形变织构的主织构与换向轧制的主织构相同,但其{110}〈112〉中各组分的强度和漫散程度不同,且强点偏移理想位置;有宏观统计不对称织构是由轧件所受的剪力而致,非正常滑移和剪切带的作用对其形成起着关键作用。     

无取向硅钢晶粒长大过程中应力对织构和晶界变化的影响

采用EBSD技术研究了有、无拉应力作用下无取向硅钢在晶粒长大过程中织构转变及晶界变化的规律。结果表明:在晶粒生长期间,无应力作用下的硅钢中,{111}〈112〉,{111}〈110〉织构组分强化,而{100}〈001〉织构组分弱化;与无拉应力作用下的情况相比,施加5MPa的拉应力时,{111}〈112〉,{111}〈110〉织构组分强化的速率下降,{100}〈001〉织构组分变化不明显。对于在晶粒生长期间持续变化的{111}〈112〉,{111}〈110〉和{100}〈001〉织构组分而言,虽然有、无拉应力作用下硅钢的{111}〈112〉和{111}〈110〉织构组分的高取向差角度晶界频率均下降,而{100}〈001〉织构组分的高取向差角度晶界频率则上升,但当有拉应力作用后,{111}〈112〉和{111}〈110〉织构组分的高取向差角度晶界频率下降的速率变小,{100}〈001〉织构组分的高取向差角度晶界频率上升的速率稍有变小。通过对无取向硅钢在晶粒长大过程中织构转变及晶界变化规律的研究,分析了合金原子在晶界的偏聚行为。     

Microtexture of chloride treated CdTe thin films deposited by CSS technique

This work investigates the microstructural changes—especially in grain boundary structure and grain orientation distribution—in CdTe thin films deposited by close spaced sublimation at low (LT) and high temperatures (HT) and submitted to a CdCl₂ heat treatment. These changes are quantitatively described by microtexture analysis, a spatial distribution of the orientation of the grains. The analysis is performed in a scanning electron microscope by means of identification of the electron back-scattered diffraction patterns from individual grains. The texture of each grain, the misorientation between grains, and coincident site lattice boundary maps are obtained. The results show that the CdCl₂ treatment did not promote significant microstructural changes in HT-CdTe films, which grow with large and randomly oriented grains, and with a predominance of high-angle boundaries. On the other hand, for LT-CdTe films, this treatment promotes a substantial increase in grain size, a decreasing of preferential orientation, and an increase in the number of CSL and high-angle boundaries. These changes are considered to be a strong evidence for recrystallization.     

IF钢再结晶晶粒尺寸、显微织构和晶界特征分布的EBSD研究

对IF钢板的罩式退火工艺和连续退火工艺进行了模拟，并运用电子背散射衍射(EBSD)技术研究了两种退火工艺处理的IF钢板的再结晶晶粒尺寸、显微织构和晶界特征分布及其与二次加工脆性间的关系。试验结果表明，两种退火工艺的IF钢板在再结晶晶粒尺寸、显微织构和晶界特征分布上存在很大的差异，这种差异导致了两种退火工艺的实验钢板在深冲性能和韧脆转变温度上的差异。     

EBSD investigation of the microstructure and microtexture evolution of 1050 aluminum cross deformed from ECAP to plane strain compression

Electron backscattered diffraction (EBSD) was used to document the microstructure and texture developed due to cross deformation of commercial purity 1050 aluminum alloy. The materials are first deformed in equal channel angular pressing die (ECAP) to different number of passes; 1,4, 8, 12, and 16 passes, via route B_C and then deformed in plane strain compression (PSC) to two axial true plastic strain values of 0.5 and 1.0. Deformation path change was proven to be a very effective tool for manipulating the evolution of microstructure and microtexture. The study provides a documentation of the evolution of microstructure parameters namely cell size, misorientation angle, fraction of submicron grain size, and fraction of high angle grain boundaries. These microstructure parameters were investigated on two planes; the plane normal to the loading direction in PSC (RD–TD) and that plane normal to the transverse direction (RD–ND). These microstructure parameters are compared to those achieved due to the ECAP process only. The ideal rolling texture orientations are depicted and crystal orientation maps were generated. The spatial distribution of grains having these orientations is revealed through these maps. The fraction of the main texture components for a 10° spread around the specified orientations is experimentally calculated and a quantitative idea on the evolution of microtexture is also presented.     

薄膜生长基底对FeS2晶体取向的影响

用Fe膜硫化法制备了FeS2薄膜,分析了基底对FeS2薄膜晶体结构和位向分布的影响.结果表明,改变基底晶体的类型能够在一定程度上控制FeS2薄膜的晶体位向分布.FeS2薄膜在Si(100)、Si(111)和Al基底上可获得(200)方向的择优取向,在TiO2基底上可同时获得(200)及(220)择优取向,非晶玻璃基底对位向分布影响不明显.不同的基底与Fe薄膜的界面错配度不同,可改变薄膜晶体位向的分布,导致晶格畸变程度和晶粒尺寸的变化.当基底为非晶结构或界面的错配度较大时,FeS2晶体的取向分布主要受表面能和晶粒优先生长方向的控制,薄膜具有较小的晶格畸变和较细的晶粒;当基底为晶态并且界面错配度较小时,FeS2晶体取向的分布除受表面能及晶粒优先生长方向控制外,还受界面应变能的控制,此时薄膜易形成较大的晶格畸变和粗晶粒.     

负偏压对Be上磁控溅射离子镀Al膜结构影响的研究

以Be为基体，采用磁控溅射离子镀的在其上镀制Al膜，研究了负偏压对Al膜微结构的影响；研究表明，不加基体负偏压，Al膜在（111）面择优生长；随着基体负偏压升高Al膜在（111）面择优生长趋势减北，Al膜在（200）面生长趋势加强；当基体负偏压超过150V后，Al膜在（111）面择优生长的趋势又得到加强。晶粒在低负偏压时随负偏压增加而细化，当较高的负偏压引起基体温度升高时，此时晶粒又变大了。     

Modelling of continuous recrystallization in aluminium alloys

Microstructure and microtexture analyses have been made of three aluminium alloys after annealing alone and after concurrent straining and annealing, and simulative models of microstructure/microtexture evolution processes have been formulated. Both experimental and modelling results are presented as boundary misorientation distributions. For each alloy, the results show that annealing alone does not significantly alter the boundary misorientation distribution, while concurrent straining and annealing (up to a strain of 0.5) decreases the fraction of low-angle boundaries. To understand the mechanisms by which concurrent straining and annealing alter the boundary misorientation distribution, three simulative models of microstructure/microtexture evolution during concurrent straining and annealing have been formulated. Application of the models to experimentally determined initial microstructure/microtexture states shows that the boundary sliding (sub)grain rotation model decreases the fraction of low-angle boundaries, the dislocation glide (sub)grain rotation model increases the fraction of low-angle boundaries, and the (sub)grain neighbour switching model has a modest effect on the boundary misorientation distribution. A combination of the boundary sliding (sub)grain rotation model and the (sub)grain neighbour switching model most closely reproduces the boundary misorientation distributions found experimentally.     

A microstructural approach to flaw size dependence of strength in engineering ceramics

In this work, microstructural effects on the flaw size dependence of ceramic strength were investigated from aspects of stress analysis in the grain just ahead of the crack tip and also R-curve behaviour. In the analysis, it was assumed that the stress averaged in one grain just ahead of the crack tip, in ceramics, might control the fracture from a flaw. A microstructurally modified fracture criterion using the averaged stress was established by introducing the R-curve due to the grain bridging effect for longer cracks. A new R-curve of an exponential type was proposed for the fracture criterion. The criterion could adequately express the central trend in the dispersal of experimental results in the strength versus flaw size relation. To explain the scatter of results, the size distribution and the crystallographic anisotropy of the grain ahead of the crack tip were examined as dominant factors. The lower bound of strength scatter was estimated from the largest grain size, and the strength dispersion was reduced by decreasing the range of grain size variation. In FEM simulations, each element was regarded as one grain with a different crystallographic orientation, which was randomly selected by using a series of quasi-uniform random numbers. It was revealed that the scatter of strength due to crystallographic variations was smaller than the strength dispersion caused by a distributed grain size.     

冷轧纯铜微观组织及织构演变的特征

介绍了电子背散射技术（EBSD）在材料织构方面的研究应用状况,并采用EBSD研究了纯铜在冷轧过程中晶粒的变化、晶粒取向及晶界角度分布的特征。结果表明,纯铜在经过大变形量后出现轧制织构,其轧制织构主要是{112}〈111〉和{011}〈112〉织构;在中小变形量下,随着变形量的增加大角度晶界逐渐减少,而到高变形量时逐渐增加。     

The application of the etch-pit method to quantitative texture analysis

The etch-pit method is a useful technique for studying the grain orientation in polycrystalline materials. In this paper, the etch-pit method is extended to obtain a quantitative analysis of the texture of materials. From the experimental results, the orientation distribution function (ODF) and the misorientation distribution function (MODF) can be calculated. The computer program developed for this analysis returns the grain size distribution of different texture components and the frequency of coincidence site lattice (CSL) boundaries, as well as other data. This information is used to analyse the grain growth and texture development in transformer steel.     

尺寸效应对TiC/α-C∶H涂层织构行为的影响

利用磁控溅射法制备了TiC/α-C∶H纳米复合涂层尺寸效应,并对涂层择优取向的影响进行了研究。通过改变涂层中的C含量来调节晶粒尺寸,发现晶粒尺寸对晶粒的择优取向有着重要影响。随着晶粒尺寸减小,TiC的择优取向从面心立方(111)向(200)转变。这种择优取向的尺寸依赖效应可以用热力学来解释。通过计算与尺寸相关的吉布斯自由能解释了尺寸效应与涂层择优取向的关系。