深冲汽车簿钢板织构的表述方法

利用晶体学性质,将深冲汽车薄板的两种主要特征织构表述于反极图之中,再利用织构定量技术便能简捷地分析深冲钢板的织构与深冲性能的关系。经验证,此法与ODF定量分析所得的结果一致。     

现代织构分析的进展

本文系统阐述了材料现代织构分析的进展。     

论OA系统的文档类型

本文论述了在开发OA系统过程中,如何选择合适的文档类型。文中给出了具体方案,并对文档类型的标准化及未来的发展趋势进行了分析。     

板材冲压成形的晶体塑性有限元模拟

将率相关晶体塑性本构理论引入Mindlin曲壳单元模型与动力显式有限元法,采用切线系数法计算剪切应变率,根据晶体取向正态分布规律在单元积分点处分配晶体取向,按各晶体取向体积分数的加权平均计算多晶体应力,开发晶体塑性动力显式有限元程序,实现板材冲压成形过程模拟和晶体取向演化预示.以主要初始织构为铜织构和S织构的轧制铝板为对象,对方盒件冲压成形过程及织构演化进行数值模拟,计算结果与试验结果呈现出较好的一致性.通过晶体弹塑性有限元法不仅可以预示板材宏观成形构形变化,而且能够预测板材织构的演化情况.模拟结果显示在方盒件冲压成形过程中,铜织构和S织构为不稳定取向,变形后逐渐转到其他取向.     

High Angular Resolution Diffusion MRI Segmentation Using Region-Based Statistical Surface Evolution

In this article we develop a new method to segment high angular resolution diffusion imaging (HARDI) data. We first estimate the orientation distribution function (ODF) using a fast and robust spherical harmonic (SH) method. Then, we use a region-based statistical surface evolution on this image of ODFs to efficiently find coherent white matter fiber bundles. We show that our method is appropriate to propagate through regions of fiber crossings and we show that our results outperform state-of-the-art diffusion tensor (DT) imaging segmentation methods, inherently limited by the DT model. Results obtained on synthetic data, on a biological phantom, on real datasets and on all 13 subjects of a public NMR database show that our method is reproducible, automatic and brings a strong added value to diffusion MRI segmentation.

蚀坑法测定铝合金板材织构

介绍了蚀坑法的原理和计算方法,并用蚀坑法和X射线衍射ODF(取向分布函数)图分别测定了HL01铝合金板退火后的再结晶织构.结果表明,再结晶织构主要有戈斯织构、立方织构、S织构、R织构及少量铜型和黄铜R织构.用蚀坑法可以定性测定材料的织构.     

表征非晶聚合物分子取向分布的ODF分析法

本文对单轴取向非晶聚合物的分子分布状态进行了物理描述和数学表征，详细论证了广角Ｘ射线方法测定和计算全取向分布函数ＯＤＦ（Ａｌｌ ｏｒｉｅｎｔａｔｉｏｎ ｄｉｓｔｒｉｂｕｔｉｏｎ ｆｕｎｃｔｉｏｎ）。在此基础上，用Ｆｏｒｔｒａｎ语言编写计算ＯＤＦ的ＯＤＦ９２型程序，并用于单轴取向蜚 晶态聚脂（ＰＥＴ）的取向分布分析，获得 了令人满意的结果。     

Influence of Rolling Reductions on Recrystallization Texture in Commercially Pure Al

The recrystallization texture in commerciallypure Al is investigated after the samples are rolleddifferently and annealed.The samples with low rol-ling reductions could be generally recovered orrecrystallized in situ and characterized by the re-tained G{110}<001>component.This recoveryprocess decreases during annealing with the increaseof reduction.The appearance of the B/R{359}.<132>and R{123}<634>components de-pending on the rolling reduction is investigated andthe less developed Cube{100}<001>componentin commercially pure ahninium is also discussed.     

Mechanism of strengthening of cube texture for high purity aluminum foils by additional-annealing

1　INTRODUCTIONHighpurityaluminumfoilsareusedastheanodematerialofhighvoltageelectrolyticcapacitorswhichneedstrongcubetexture { 0 0 1}〈10 0〉forlargeeffec tivesurfacefromchanneletching[1] .Becauseofitstechnicalimportance ,alotofeffortshavebeenmadetodevelopstrongcubetextureinhigh purityalu minumfoils[2 8] .Itwasfoundthatthecubetextureinthefoilscanbestrengthenedviaanannealingpro cessfollowedbyalowcoldrolling[7,8] ,andsuchanannealingiscalledadditional annealinginthispaper .Buttherewerefewinv…     

ODF工艺中边框胶穿刺的影响因素研究

根据ODF(OneDropFilling)工艺的实际生产情况,探讨了液晶量、边框胶涂布效果、关键工艺生产节拍(TactTime)和外围边框胶(DummySeal)设计方式对边框胶穿刺情况的影响,发现ODF工艺中液晶与未固化的边框胶接触是发生边框胶穿刺的根本原因。液晶量越大边框胶穿刺情况越严重;边框胶涂布效果的直线性越好,其穿刺情况越轻微;液晶与未固化边框胶的接触时间越长,其穿刺情况越严重,甚至出现大量漏液晶;外围边框胶开口式设计有利于改善边框胶穿刺情况。