孪晶对CVD金刚石薄膜宏观织构组分的影响

采用X射线研究了CVD金刚石薄膜的织构,并采用扫描电镜观察了金刚石薄膜的表面组织形貌,探讨了孪晶对金刚石薄膜织构的影响.结果表明,高频率的孪晶会影响薄膜的织构,高频率孪晶导致没有形成{100}织构,而形成{122}织构.     

磁控溅射Pt薄膜织构的X射线衍射分析

本文利用X射线衍射技术表征了磁控溅射Pt薄膜的纤维织构.并给出了一种表征薄膜纤维织构的一般性方法.研究结果表明,利用X射线衍射的特殊扫描方式可以实现薄膜纤维织构的定量和定性表征.对于制备态Pt薄膜而言,织构漫散 400℃退火后,薄膜{111}型纤维织构变强,表明Pt薄膜的强{111}织构系退火时薄膜的再结晶所致.     

不同轧制方式对铌箔微观组织和织构的影响

采用取向分布函数(ODF),并通过光学金相(OM)显微组织观察,研究分析经4种不同轧制方式变形及其在1 050℃退火1h过程中微观组织和织构的演变.研究结果表明:对于顺轧变形方式的铌箔,经1 050℃退火1h后较其他3种轧制方式晶粒细小均匀,晶粒的平均尺寸约为40μm;交叉轧制变形方式能形成较强的{001}＜110＞形变织构,并且经退火后能强化{111}＜uvw＞再结晶织构,有利于提高铌材的深冲性能,同时减少{001}＜100＞立方织构,而其他3种轧制方式对{001}＜l00＞织构具有强化作用;4种不同轧制方式变形不能强化{111}＜110＞形变织构.     

不同取向条件下Al-Mg-Sc合金薄板的组织与性能

采用室温拉伸性能测试、金相组织观察、透射电子显微分析以及取向分布函数(ODF)测定研究冷轧态、冷轧-退火态Al-Mg-Sc合金(俄罗斯牌号01570)薄板在不同取向条件下的显微组织和力学性能.研究结果表明:合金薄板在横向、纵向和与纵向成30°方向的强度比45°和60°方向上的强度高,横向力学性能优于纵向力学性能,在45°方向的屈服强度最低,伸长率最高;冷轧态铝合金薄板具有明显的Brass织构{110}<112>,Copper织构{112}<111>和S织构{123} <634>,经350℃退火1h后板材的织构组态变化不大.合金板材中弥散析出的Al3(Sc,Zr)粒子会促进{011}<112>变形织构的形成与稳定,阻止立方织构{100}<001>的形成;不同取向条件下Al-Mg-Mn-Sc-Zr合金薄板的平面各向异性与合金的晶粒结构及晶体学织构密切相关.     

退火时间对高强细晶IF钢再结晶织构的影响

以含铌高强细晶IF钢为研究对象,在不同保温时间下进行了连续退火实验。通过采用OM显微分析及EBSD测试技术对实验钢进行显微组织和微观织构观察分析,得到含铌高强细晶IF钢在退火过程中织构的演变规律。实验结果揭示:高强细晶IF钢在连续退火过程中形成较强的111//ND再结晶织构。当退火温度为850℃,保温时间为120 s时,钢板具有最强的111//ND织构;随着保温时间的增加,111//ND织构逐渐增强,110//RD先减弱后增强。再结晶织构在{111}面与{112}面之间转化并发生漫散现象。     

异速比对异步轧制AZ31镁合金板材组织和织构的影响

采用不同异速比对AZ31镁合金板材进行异步轧制,并将轧后样品进行显微组织和X射线衍射分析,研究异速比对镁合金板材组织和织构转变的影响. 结果表明:异速比的变化对晶粒形貌影响较大但晶粒细化效果不明显;当异速比为2.800时,板材内出现了长条晶粒;快速辊侧{0002}基面织构强度高于慢速辊侧,且板材两侧表面{0002}晶面的偏转方向相反;异速比对基面织构的强度影响显著,随着异速比的增大,基面织构的强度先增加后下降. 这种特殊的织构变化与异步轧制过程中沿厚度方向引入的剪切变形有关.     

含铌Hi-B钢织构的演变

以两种含Nb量不同的Hi-B钢为研究对象,借助OM、SEM及XRD研究了试验钢在常化、冷轧及脱碳退火过程中织构的演变规律。结果表明,两组试验钢常化板沿板厚方向存在织构差异,表层及次表层主要为{110}112、{112}111及Goss织构组分,中心层以{001}110、{111}112及{112}110织构组分为主,除次表层Goss织构外,低Nb钢中各织构组分含量均高于高Nb钢;冷轧过程中,{112}111和{110}001织构转变为{111}面织构,{112}110织构转向{001}110织构,高Nb钢中各织构组分含量均高于低Nb钢;脱碳退火过程中,两组试验钢中均形成了较强的{111}面织构,高Nb钢中含有更强的{111}面织构和更弱的Goss织构组分,并且Goss晶粒与{111}112晶粒之间的取向差更接近Σ9晶界。     

退火时间对高强细晶IF钢再结晶织构的影响

以含铌高强细晶IF钢为研究对象,在不同保温时间下进行了连续退火实验.通过采用OM显微分析及EBSD测试技术对实验钢进行显微组织和微观织构观察分析,得到含铌高强细晶IF钢在退火过程中织构的演变规律.实验结果揭示：高强细晶IF钢在连续退火过程中形成较强的〈111〉//ND再结晶织构.当退火温度为850℃,保温时间为120 s时,钢板具有最强的〈111〉//ND织构;随着保温时间的增加,〈111 〉//ND织构逐渐增强,〈 110〉//RD先减弱后增强.再结晶织构在{111}面与{112}面之间转化并发生漫散现象.     

半工艺无取向硅钢加临界变形的织构演变

测定了半工艺无取向电工钢热轧(终轧温度在Ar1以下)到成品各工序的织构,以取向分布函数(ODF)的形式对加临界变形的半工艺无取向硅钢的织构演变作了分析.发现其热轧板表层织构基本是典型的铁素体再结晶{111}组分,心部和1/4厚度处以铁素体剪切织构和轧制变形织构为主.冷轧变形后,心部和表层织构组分比较接近,{111}、{112}和{100}面织构都增加,但{111}组分增加最明显.软化退火后,{001}<110>与{112}<110>组分迅速降低,织构组分以γ纤维织构为主.通过增加临界变形,在最终去应力退火后,{111}不利面织构大量减少,高斯组分增加明显.Taylor因子可以表征不同取向晶粒对变形能的储存能力,从轧制变形时Taylor因子的分布可以解释该实验结果.     

退火温度对Ti-IF钢性能及织构的影响

对冷轧压下率为80%、厚1mm的Ti-IF钢经不同温度退火处理后进行拉伸试验,测量其塑性应变比r值.观察退火试样的显微组织,并利用电子背散射衍射技术(EBSD)对其性能和再结晶织构进行分析.结果表明,冷轧试验钢分别在780、810、840℃退火3min后,均发生了再结晶;随着退火温度的升高,大多数晶粒尺寸由5～6μm增大到9～10μm;试验钢的r值随退火温度升高而增大;退火钢再结晶织构表现为强烈的{111}织构,主要由{111}〈110〉和{111}〈112〉两类取向晶粒组成.     

CVD金刚石薄膜的织构分析

采用极图和取向分布函数法分析ＣＶＤ金刚石江膜的不同织构,分析表明,高的多重性因子使得｛１１０｝面织构有更高的出现概率,具体分析了｛２２１｝面织构出现的孪生机制,强调了织构与性能关系研究的重要性,并推荐使用先进织构分析手段。     

CVD金刚石膜{100}取向生长的原子尺度仿真

运用动力学蒙特卡洛(KMC)方法从原子尺度对CVD金刚石膜{100}取向在3种不同化学反应模型下的生长进行了仿真.结果表明:(1)以CH3为主要生长组元的生长机制比较适合于{100}取向金刚石膜的生长;(2) 对金刚石{100}取向而言,含有双碳基团的模型沉积速度并不比含有单碳基团的模型沉积速度大;(3)在高的生长速率下仍有可能获得表面粗糙度较小的金刚石膜;(4)对Harris模型的仿真结果与其本人的预测结果一致,并与实验结果符合良好.     

Atomic scale KMC simulation of {100} oriented CVD diamond film growth under low substrate temperature—Part Ⅰ Simulation of CVD diamond film growth under Joe-Badgwell-Hauge model

The growth of {100} oriented CVD (Chemical Vapor Deposition)diamond film under Joe-Badgwell-Hauge (J-B-H) model is simulated at atomic scale by using revised KMC (Kinetic Monte Carlo) method. The results show that: (1) under Joe's model, the growth mechanism from single carbon species is suitable for the growth of {100} oriented CVD diamond film in low temperature; (2) the deposition rate and surface roughness () under Joe's model are influenced intensively by temperature ()and not evident bymass fraction of atom chlorine; (3)the surface roughness increases with the deposition rate, i.e. the film quality becomes worse with elevated temperature, in agreement with Grujicic's prediction; (4) the simulation results cannot make sure the role of single carbon insertion.     

Atomic scale KMC simulation of {100} oriented CVD diamond film growth under low substrate temperature-Part II Simulation of CVD diamond film growth in C-H system and in Cl-containing systems

The growth of {100}-oriented CVD diamond film under two modifications of J-B-H model at low substrate temperatures was simulated by using a revised KMC method at atomic scale. The results were compared both in Cl-containing systems and in C-H system as follows: (1) Substrate temperature can produce an important effect both on film deposition rate and on surface roughness; (2) Aomic Cl takes an active role for the growth of diamond film at low temperatures; (3) {100}-oriented diamond film cannot deposit under single carbon insertion mechanism, which disagrees with the predictions before; (4) The explanation of the exact role of atomic Cl is not provided in the simulation results.     

Mechanical performance and texture characteristic of an IF steel containing Nb and Ti by double cold rolling

Single cold rolling and double cold rolling were applied to hot rolled strips with different reduction ratios. The evolutions of { 100}, { 111} and Goss face texture during double rolling were investigated by comparing the orientation distribution function (ODF) of the double rolled sample with that of the single rolled one. The double cold rolling texture is characterized by a higher γ-texture and a lower α-texture, and the { 111}〈112〉 component is improved remarkably. Based on the TEM observation and mechanical properties test, it is found that the reduction ratio assignment significantly affects the texture variation, as-annealing microstructures, and properties of the double cold rolled samples. These results may provide a theoretical guide for the industrial production of double cold rolled IF steel.     

Ta-7.5％W在退火过程中的组织和织构演变

通过金相组织观察、透射电子显微镜(TEM)及显微硬度测试,研究冷轧变形量为95％的Ta-7.5％W合金箔材在1 050,1 200和1 360℃退火时的组织和性能变化,并采用取向密度函数(ODF)分析在此过程中其织构演变规律.对其实验结果进行研究发现:冷轧态Ta-7.5％W合金硬度为HV 300,经1 360℃退火后硬度迅速减小,说明此时合金已发生回复再结晶.轧制后的Ta-7.5％W合金箔材具有各向异性,在轧面∥{111}取向上形成位错胞亚结构,在轧面∥{100}取向上形成了形变带,冷轧态的主要织构为{001}〈110〉,{112} 〈110〉和{110}〈110〉织构;在1 200℃退火时,在轧面∥{111}取向上,再结晶通过亚晶界迁移、亚晶长大形核,而在轧面∥{100}取向上,主要是通过亚晶转动、聚合形核;{001}〈110〉织构增强,{112}〈110〉织构减弱;在1 360℃退火时,{001}〈110〉织构急剧减弱,{111}〈112〉织构增强.     

Microstructure and texture evolution of cold-rolled deep-drawing steel sheet during annealing

In accordance with experimental results about the annealing microstructure and texture of cold-rolled deepdrawing sheet based on the compact strip production (CSP) process, a two-dimensional cellular automation simulation model, considering real space and time scale, was established to simulate recrystallization and grain growth during the actual batch annealing process. The simulation results show that pancaked grains form during recrystallization. {111} advantageous texture components become the main parts of the recrystallization texture. After grain growth, the pancaked grains coarsen gradually. The content of {111} advantageous texture components in the annealing texture increases from 55vol% to 65vol%; meanwhile, the contents of {112}〈110〉 and {100}〈110〉 texture components decrease by 4% and 8%, respectively, compared with the recrystallization texture. The simulation results of microstructure and texture evolution are also consistent with the experimental ones, proving the accuracy and usefulness of the model.     

Deposition of crackless freestanding diamond films on Mo substrates with Zr interlayer

The Mo substrate with Zr interlayer, namely composite substrate, was employed to solve the problem of crack formation in the freestanding diamond film deposition. Freestanding diamond films deposited on the composite substrates by the direct current arc plasma jet chemical vapor deposition (CVD) method were investigated with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. In addition, the stress distribution during the large area freestanding diamond film deposition on the composite substrate was analyzed based on the finite element model ANSYS. The results reveal that Zr interlayer can be easily destroyed during the post-deposition cooling process, which is helpful for stress release and crack avoiding in diamond films.     

大面积金刚石膜生长环境气氛的计算机模拟

建立了直流电弧等离子体喷射ＣＶＤ大面积金刚石沉积数学模型．对衬底上方等离子 体中的化学环境进行了模拟计算,并与在相同条件下对等离子体的光谱结果进行对比,发现计 算结果与实验结果基本上吻合．在模拟条件下ＣＨ基团可能是促使金刚石生长的主要活化基 因．模拟结果显示ＣＨ基因沿径向的均匀分布对大面积金刚石膜生长有较大的意义．     

3%Si无取向硅钢异步轧制织构的演变

对无取向硅钢常化态板材经过异步轧制,轧制速比为1.06,经过一次冷轧到0.5 mm厚,压下率为77.3%,并在保护气氛下进行再结晶退火,考察了异步冷轧织构和再结晶织构形成及演变.常化态板材的初始织构组分以{110}和{113}织构为主,异步冷轧织构主要是由α织构和γ织构组成,快慢辊侧的织构类型没有变化,但慢辊侧α织构和γ织构的取向密度明显高于快辊侧;再结晶退火后α织构取向密度明显减弱,而γ织构的变化主要是{111}〈110〉织构组分的取向密度减弱,{111}〈112〉织构组分的取向密度加强.