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.     

工业纯钛板材冷轧及退火微观组织和织构演变规律

采用先进电子背散射衍射（EBSD）技术,深入研究了冷轧工艺变化和道次间退火处理对工业纯钛板材微观组织和织构演变的影响规律。通过对比不同一次冷轧变形量样品经退火和二次冷轧加工后的EBSD取向分布图、取向差角分布图和极图得知,一次冷轧产生的孪晶对退火再结晶晶粒尺寸及晶粒取向（织构）产生重要的影响,进而又影响二次冷轧的变形组织和织构特征,使二次冷轧变形孪晶的生成受到一定程度的抑制,孪晶分数随着轧制变形量的提高呈现先升高后降低的规律,同时会降低二次冷轧组织中{0001}基面织构组分。     

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.     

CP 276铝锂合金的高温拉伸性能

研究了ＣＰ２７６合金薄板材料在１００～２５０℃时的高温拉伸性能和高温变形组织特征。实验结果表明：ＣＰ２７６合金在２００℃拉伸时的屈服强度可达室温屈服强度的７０％以上，显示良好的高温性能；高温变形时的强化与被切割的δ＇粒子重新恢复有序结构以及热激活形成的交滑移障碍有关；随着变形温度提高，时效前的预变形引起的强化作用减弱；高温变形时，由于位错交滑移和动态回复的结果，形成了以位错网络和胞状亚结构为特征的变形组织。     

快速加热时含微量砷冷轧电工钢的织构变化

采用取向分布函数（ＯＤＦ）方法，对含微量砷无取向电工钢冷轧后再加热过程中织构的变化进行研究。将含０．０３５％和０．０７２％砷的冷轧电工钢板快速加热，｛１１１｝∥ＮＤ纤维织构组分等在６３０～７２０℃范围内显减弱，表明该材料在此温度范围内已发生再结晶转变。含砷量从０．０３５％增加到０．０７２％，促进了无取向电工钢的再结晶转变。     

SPCE冷轧带钢的力学性能分析

对ＳＰＣＥ冷轧带钢的性能各向异性及其抗拉强度与压下率的相关关系进行了研究。通过采用合理的热处理及平衡工艺得到了有利于改善钢带各向异性及深冲件表面质量的织构及组织类型，又运用线性回归方法，建立了冷轧带钢抗拉强度与压下率的相关关系。以上两种研究结果，对冷轧带钢的实践生产有着指导意义。     

时效热处理对波纹管Inconel718材料性能的影响

通过金相显微镜,透射电镜对厚度为０．１２ｍｍＩｎｃｏｎｅｌ７１８材料相组织、位错、二次相析出进行分析和力学性能实验,结果表明,固溶冷轧薄板位错密度高,为奥氏体组织,经时效热处理后在奥氏体基体上析出了弥散的强化相（γ′相Ｎｉ３Ａｌ）和γ″相（Ｎｉ３Ｎｂ）,分布密度与时效时间有关,γ′相,γ″相的析出优先在位错区产生,时效处理后,冷轧变形的位错密度有所下降,析出的弥散的强化相γ′和γ″相使材料的显微硬     

异步轧制取向硅钢织构的模拟研究

本文系统地阐述了异步轧制剪切变形条件下板材冷轧织构的模拟计算理论；采用矢量法根据实测的ＯＤＦ构造板材的原始组织、在假设临界滑移系开动几率均等的条件下，运用Ｔａｙｌｏｒ模型对取向硅钢的亚表层和中心层的冷轧织构进行电算模拟；在此基础上，对剪切变形条件一些轧制因素的影响进行了讨论。     

2091铝锂合金织构

铝锂合金材料性能的各向异性主要是由于织构存在而形成的．因此，根据作者于１９９４年提出的从一张完整极图计算ＯＤＦ的最大熵技术，测算了２０９１铝锂合金，在冷轧和退火过程中织构变化．该技术的极图测算量小，精度较高，准确可靠．样品采用组合试样．实验研究结果表明：该合金冷轧时形成较强的（１２１）［２３４］织构；退火过程中，再结晶织构类型和漫散范围没有明显改变，只是随着退火温度的升高，织构的强度明显降低     

不同取向条件下Al-Cu-Mg-Sc-Zr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T3态Al-Cu-Mg-Sc-Zr合金(2524SZ-T3)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:合金薄板在与轧制方向呈30°,60°和90°方向上的强度较0°和45°方向上的强度稍低,伸长率则在60°方向上最高,薄板的抗拉强度、屈服强度和伸长率平面各向异性指数分别为0 9％,3 3％和6.6％; 2524SZ-T3态铝合金薄板具有明显的再结晶织构｛110}〈111〉和CubeND旋转立方织构{001}〈310〉,同时还保留较弱的轧制织构即Goss织构{011} <000〉;不同取向条件下2524SZ-T3合金薄板的平面各向异性与合金的晶粒结构以及晶体学织构密切相关.     

Influence of different rolling processes on microstructure and strength of the Al–Cu–Li alloy AA2195

The influence of different rolling processes on precipitation behaviour, crystallography texture, grain morphology, and their consequent effects on tensile properties for Al–Cu–Li alloy AA2195 was investigated in the present work. The H-T8 samples (hot rolled ?+ ?T8) presented better tensile strength and ductility (with serious strength anisotropy) than the HC-T8 samples (hot rolled ?+ ?cold rolled ?+ ?T8), due to their different microstructures and textures. The higher dislocation density was found in the H-T8 samples, which promoted the nucleation of main strengthening phase T₁ in the matrix and suppressed the grain boundary precipitation, resulted in better strength and ductility. The increase of the dynamic recovery (DRV) during hot rolling enhanced the generation of Brass texture, and brought serious strength anisotropy. The cold rolling was performed after the hot-rolling process for the HC-T8 samples which increased deformation energy and resulted in full recrystallization of the deformed microstructure during the following solution treatment. The formation of recrystallized microstructure reduced the dislocation density and the heterogeneous precipitate nucleation positions which limited the strengthening phase precipitation in matrix and accelerated the precipitation along grain boundaries, resulted in fewer T₁ precipitates, coarse grain-boundary precipitates (GBPs), and wider precipitate-free zones (PFZs). The localized strain may be concentrated on the grain boundary to induce the dislocation pile-up, breaking of the GBPs, and intergranular fracture during stretching.     

深拉筒形制品用冷轧钼板的力学性能与显微结构分析

冷轧钼板各向异性是造成深拉筒形制品成材率低的基本原因.本文研究的两次交又轧制工艺制取的钼板明显减少了力学性能的各向异性,并且呈现形变软化现象,研究表明是由于{111}面织构增多及显微结构、位错组态变化的结果.生产证明该工艺已取得较好的经济效益.     

Phase formation,texture evolutions,and mechanical behaviors of Al0.5CoCr0.8FeNi2.5V0.2 high-entropy alloys upon cold rolling

The cold rolling (CR) reduction dependence of microstructure evolutions and mechanical properties for Al_0.5CoCr_0.8FeNi_2.5V_0.2 high-entropy alloy (HEA) were investigated. The HEA remains FCC structures consisting of nanoscale ordered L1₂ phase, confirming the phase formation prediction. With increasing CR reduction, the textures transform from random ones to FCC rolling ones accompanied by dense slip bands and deformation twins. Under a 50% CR reduction, the deformation textures started to become evident and were governed by typical {111}<112>F, {110}<100>Goss and {112}<111>Cu texture components. When the CR reduction approached 90%, the deformation textures mainly contained the {110}<111>A, {114}<110>X, and {112}<111>Cu texture components. As a result, both Vickers hardness and ultimate strength increased, but the ductility decreased roughly. The enhanced strength should be attributed to the anisotropy and work hardening behavior from textures. The plastic deformation for the samples under low CR reductions was dominated by deformation twins and slip bands. However, under high CR reductions, the textures severely impeded the further propagation of pre-existing slip bands, leading to the rapid decrease of ductility. Therefore, the CR reduction should be carefully designed before optimal heat treatments to enhance the strength and ductility synergy.     

Effect of cold rolling process on microstructure and mechanical properties of high strength β titanium alloy thin sheets

The microstructure and mechanical properties of Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe high strength titanium alloy sheets prepared by unidirectional cold rolling and two-step cross cold rolling were investigated. Results showed that the β phase grains were refined significantly by cold rolling followed by solution treatment for a short time.Compared to unidirectional cold rolling, the short time solution treatment after two-step cross rolling could significantly reduce the non-uniformity of the microstructure of the alloy sheets. After aging treatment at 550 ℃,the anisotropy of the mechanical properties still existed in the unidirectional rolled sheets, and the tensile strength was highest along the rolling direction. After solution and aging treatment, the anisotropy of the mechanical properties of the two-step cross rolling process sheet was not obvious than unidirectional cold rolling,and alloy had good strength and plasticity matching.     

Impact of asymmetry deformation on microstructure and mechanical properties of AZ31B alloy sheets deformed by on-line heating rolling

The effect of asymmetry deformation on microstructure and mechanical properties of AZ31 sheet was investigated in the present paper. Two AZ31 sheets were rolled together with an on-line heating rolling mill and separated from each other afterwards. For each sheet, the strain on both surface during rolling was asymmetry and this rolling method is called asymmetry rolling (AR) in present work. For comparison, symmetry rolling (SR) was also carried out on the same rolling mill that only one sheet was rolled in one pass. The sheets deformed by AR showed more homogeneous microstructure with higher recrystallization level and symmetry distributional basal texture. Moreover, SR sheets showed many narrow shear bands which distributed as “V” shape along rolling direction, while less shear bands with wider size are observed in AR sheet. The shear bands in AR sheet distributed as a line and across the entire thickness of the sheet, resulting in layered bimodal structure. Based on the unique microstructure and texture characteristics, AR sheet has lowest mechanical property anisotropy and a good balance of strength and elongation.     

织构对NiTi合金相变伪弹性的影响及其计算机模拟

近等原子比热轧态NiTi合金板材有较显著的择优取向,使该合金的相变伪弹性呈现明显的各向异性.拉伸实验表明拉伸轴沿与轧向成45°夹角的方向,相变伪弹性最好;沿轧向,次之;沿横向,最差.文中对NiTi织构进行了取向分布函数定量分析,并改进了NiTi单晶相变应变的晶格变形矩阵理论,以取向分布密度为加权因子,对该合金多晶的相变伪弹性进行了计算机模拟,所得结果与实测值吻合得较好.     

汽车用TWIP钢的力学性能与微观组织

采用热轧、冷轧及退火处理等工艺,对成分为25Mn-3Si-3Al的TWIP钢进行了试制,研究了钢板的力学性能、微观组织及其断裂机制,并采用X射线测定了钢板的晶体学织构.实验结果表明:钢板拉伸时发生典型的延性断裂;拉伸前的组织为伴有大量退火孪晶的奥氏体;在拉伸过程中退火孪晶转变成形变孪晶,使产品的强度和塑性提高;退火过程中形成的织构组分有利于塑性变形.     

Microtextural evolution of different TRC AA8006 alloy sections with homogenization

Grain microtexture evolution in twin-roll cast AA8006 alloy sheets subjected to different treatments was investigated using electron backscatter diffraction. The textures of rolling-transverse and normal-transverse sections were characterized in original as-cast twin-roll casting and cold-rolled samples as well as samples homogenized at 500℃ for 8 h and at 580℃ for 4 h. It is found that grains on both the rolling-transverse and normal-transverse sections of cold-rolled samples are made finer by rolling deformation and coarsened after homogenization. Annealing temperature has a stronger effect on the microstructural evolution than annealing time. The grain growth direction is parallel to the normal-transverse section, while grain deformation is more stable on the rolling direction than on the normal direction. The rolling orientations display more obvious anisotropy on the normal-transverse sections than on the rolling-transverse sections. Grain recrystallization and growth occur much easier on the normal-transverse section than on the rolling-transverse section for samples homogenized at 500℃ for 8 h. A special misorientation relationship between cold deformation texture, such as S orientation {123}<634> and cube orientation <110>‖X_axis[cubic], and recrystallization texture after homogenization, such as R orientation {124}<211> and P orientation {011}<122>, is observed.     

薄带连铸Cr17铁素体不锈钢的织构演变

以具有不同初始组织的Cr17铁素体不锈钢双辊连铸薄带为实验材料,分别进行相同的冷轧及退火处理,对织构演变进行了对比研究.结果表明:织构演变与薄带的初始组织、织构密切相关.柱状晶薄带具有显著的(001)//ND织构,等轴晶薄带则具有微弱的随机织构;两者经冷轧后都形成了较温和的α纤维织构及较均匀的γ纤维织构,但是,后者的α...     

Effect of particle size distribution on the microstructure,texture, and mechanical properties of Al–Mg–Si–Cu alloy

The effect of particle size distribution on the microstructure, texture, and mechanical properties of Al–Mg–Si–Cu alloy was investigated on the basis of the mechanical properties, microstructure, and texture of the alloy. The results show that the particle size distribution influences the microstructure and the final mechanical properties but only slightly influences the recrystallization texture. After the pre-aging treatment and natural aging treatment (T4P treatment), in contrast to the sheet with a uniform particle size distribution, the sheet with a bimodal particle size distribution of large constituent particles and small dispersoids exhibits higher strength and a somewhat lower plastic strain ratio (r) and strain hardening exponent (n). After solution treatment, the sheet with a bimodal particle size distribution of large constituent particles and small dispersoids possesses a finer and slightly elongated grain structure compared with the sheet with a uniform particle size distribution. Additionally, they possess almost identical weak recrystallization textures, and their textures are dominated by CubeND {001}<310> and P {011}<122> orientations.