Cold Rolling Texture in Ordered CuZn Alloy

The texture of 80% cold rolling CuZn ordered alloy was investigated. The development of rolling texturein 50%Cu-50%Zn(at.) alloy has been characterized by a inhomogenous {111} fiber texture with strong {111} <112>component, which is significantly different from the conventional Cu-Zn alloys. The main characters of cold rollingtextures in ordered CuZn alloy are obviously similar to that in IF steel with bcc structure or ordered Fe3A1-basedalloys with imperfect B2 structure. From the rolling texture obtained by experiments and simulations,it can be estimated that main deformation mechanism are characterized by the activation of slip systems with <111> Burgersvector in CuZn ordered alloy.

Strength enhancement of Mg-3Gd-1Zn alloy by cold rolling

The severe cold rolling was employed to enhance strength of Mg-3Gd-lZn （mass fraction, %） alloy sheet. The 0.2% yield stress of the Mg-3Gd-1Zn hot-rolled sheet can be increased by 150% through the single-pass cold rolling with the reduction of 23%, due to the high intensity of dislocation and basal texture established during cold rolling. Compared with the Mg-3Gd-lZn hot-rolled sheet, the cold-rolled sheet annealed at 350 for 30 min may get an enhancement in strength without a great loss of ductility. The sheet processed by multi-pass cold rolling does not show a higher strength as expected, due to the softening effect of shear bands. However, the thin slab with the thickness less than 1 mm can be produced by the multi-pass cold rolling with the annealing treatment as few as possible.

Investigation of Cold Rolling Texture and Recrystallization Texture in NiW Substrates

NiW alloys were fabricated by cold isostatic pressing, the W content being 5, 7 and 9.3 at%, respectively. The NiW substrates were obtained by rolling assisted biaxially texturing. The cold rolling and recrystallization textures of NiW substrates were systematically studied by X-ray and EBSD, which revealed a variation of rolling texture in NiW substrates with increasing W content, which also influenced the copper (C) type and brass (B) type texture, as well as the transition between them. In addition, the recrystallization texture was influenced by the cold rolling texture. The main observations are: (1) Deformation twinning and orientation banding attributed to the cross slip and it is strongly related to the stacking fault energy which has a decisive effect on the texture transition from C to B type texture in NiW substrates with the W content increase. (2) The recrystallization cube texture is strongly related to the rolling texture. The C type texture was obtained in Ni5W substrates with 99% reduction, and was beneficial for the formation of the cube texture after recrystallization. The B type texture was obtained in Ni9W substrates with 99% reduction, and it was hard to obtain the cube texture, where a large number of annealing twins were formed during recrystallization process, leading to the formation of rotating cube texture, and thereby affecting the formation of sharp cube texture in Ni9W substrate.

Effects of initial texture on deformation behavior during cold rolling and static recrystallization during subsequent annealing of AZ31 alloy

This study demonstrates that the initial texture of Mg alloy significantly affects the microstructure developed during cold rolling and the recrystallization behavior during subsequent annealing. In a sample with a texture oriented toward the normal direction(ND sample), thick and large-sized shear bands are intensively formed during cold rolling and the deformation is strongly localized along these bands. In contrast,in a sample with a texture oriented toward the transverse direction(TD sample), many {10-12} twins are formed at the early stage of cold rolling, and then, numerous small-sized shear bands are formed in these twins. Results of nanoindentation tests reveal that the cold-rolled ND sample has internal strain energy that is substantially concentrated along the shear bands, whereas the cold-rolled TD sample has a large amount of internal strain energy that is homogeneously distributed throughout the material;this latter behavior is strongly related to the extensive {10-12} twinning and the resultant microstructural variations in the TD sample. During subsequent annealing, recrystallization occurs locally along the shear bands in the ND sample, which leads to the formation of a bimodal grain structure comprising fine recrystallized grains and coarse unrecrystallized grains. In contrast, during subsequent annealing of the TD sample, static recrystallization occurs homogeneously throughout the material, which results in the formation of a uniform grain structure that mostly comprises equiaxed recrystallized grains.

Relating Initial Texture to Deformation Behavior During Cold Rolling and Static Recrystallization Upon Subsequent Annealing of an Extruded WE43 Alloy

Deformation behaviors during cold rolling and static recrystallization behaviors upon subsequent annealing of an extruded WE43 alloys with different initial textures were investigated in this study.Three types of differently textured WE43 initial alloys were labeled as samplesⅠ,ⅡandⅢ.The results showed that multiple twinning modes and basal slip dominated the deformation of samples during cold rolling.Cold-rolled sampleⅠactivated the larger number of double twins with high strain energy,accompanied by the more uniform strain distribution,than cold-rolled samplesⅡandⅢ.During subsequent annealing,recrystallized grains preferentially occurred in double twins,twin-twin intersections and grain boundaries,thereby making cold-rolled sampleⅠhave the more rapid recrystallization rate.Similar recrystallization textures formed in three types of cold-rolled samples at the recrystallization nucleation stage,and they never largely changed with the annealing time due to the uniform grain growth induced by the solute drag and the precipitation pinning at grain boundaries.After full recrystallization,the grain growth was controlled by the solute drag,instead of precipitates which were re-dissolved into the matrix.Finally,the nucleation and growth kinetics of static recrystallization were calculated,and the effects of initial texture on activation energies of recrystallization nucleation and growth were discussed.

Textures variation of 3104 aluminum alloy sheetsunder different rolling conditions

The textures variation of 3104 aluminum alloy sheets during hot rolling, cold rolling, transverse cold rolling and cross shear rolling were investigated by means of X ray ODF analysis. The results show that the main texture component {100}<011> becomes stronger with the increase of hot rolling reduction. The cold rolling textures are composed of typical "copper type" texture components C {112}<111>, S {123}<634>, R/S {124}<211>, B {110}<112> and G {110}<001>, the orientation intensities increase with increasing cold rolling reduction. Compared to the conventional cold rolling with the same amount reduction, the transverse rolling reduces the orientation intensities of each cold rolling textures components, and strengthens the {001}<110> and {110}<uvw> texture components. During cross shear rolling process, notable difference of intensity of cold rolling textures components were observed from the slow roller side to the fast roller.

Texture Development of a Cold-rolled CuZnAl Alloy

In this paper, the textures of a CuZnAl alloy, produced d by cold rolling in the dual phase state, were studied. The alloy was heat-treated to obtain a microstructure of dual phases, then, cold-rolled with intermediate annealings. The pole figures of a and 3 phases were measured separately by the texture goniometer at the surface and center of rolled sheets. The orientation distribution function analysis showed that the a phase possessed a weak texture, and the 3 phase possessed a strong a-fiber texture. Compared the textures between the center and surface it was indicated that the textures were as a whole homogeneous. The formation of such two phase textures depended mainly on the volume percents of both phases as well as the recrystallization annealing.

Effects of stress state on texture and microstructure in cold drawing-bulging of CP-Ti sheet

Three different stress states of the combination of tensile（t） stress and compressive（c） stress,t t,t c and t c c,exist in the deformed commercially pure titanium（CP-Ti） sheet during cold drawing-bulging.The textures and microstructures in the different stress state regions were investigated by means of XRD and TEM analysis.Similar development of texture and microstructure is achieved with less thickness strain under multiaxial stresses in drawing-bulging than in cold rolling.The results show that texture and microstructure are much sensitive to multiaxial stresses.Twinning is more easily activated under compressive stress than tensile stress.Prism a slip is heavily affected by tensile stress,resulting in a remarkable change of the intensity of（0°,35°,0°） texture,while pyramidal c＋a slip,forming（20°,35°,30°） texture,weakens with the increase of thickness strain in spite of stress state.

Nucleation of Cold Rolled FeCo Alloy during Annealing and Its Influence on the Formation of Recrystallization Texture

The orientation distribution of recrystallization grains formed during annealing, as well as their misorientation relationship to the deformation matrix in cold rolled FeCo alloy have been investigated. It was found that most of the recrystallization nuclei were located near the boundary area with rather random orientations, and their misorientation angles to the deformation matrix were generally very high. However a few nuclei were also observed inside the deformation grains, to which they had very similar orientations. Therefore the misorientation angles between the nuclei and the deformation matrix were generally very low. The orientation and the misorientation distributions of the nuclei have very strong influence on the recrystallization process which could result in a very weak recrystallization texture. The corresponding mechanism is discussed.

Deformation and recrystallization texture,microstructure and kinetics of Pb-Ca-Sn alloy

A Pb-0.08Ca-2Sn alloy was subjected to rolling at room temperature to different final thicknesses.Annealing treatments at temperature ranging from 80 to 120 °C led to recrystallization of the samples as shown by resistivity and micro-hardness measurements.The deformation texture determined through X-ray diffraction is qualitatively the Brass type.The measured Lankford anisotropy parameter R and its evolution are close to the determined one using a self consistent approach.The R value evolution with angle to rolling direction shows the presence of planar anisotropy and poor drawability.The recrystallization in annealing at 80-120 °C is achieved within time period up to 3×104 s.The recrystallization texture is a retained deformation texture with an emerging Cube component.

Effects of laser surface melting on crystallographic texture, microstructure, elastic modulus and hardness of Ti-30Nb-4Sn alloy

The biocompatibility of orthopedic implants is closely related to their elastic modulus and surface properties.The objective of this study was to determine the effects of cold rolling,recrystallization and laser surface melting(LSM)on the microstructure and mechanical properties of a biphase(α″+β)Ti-30Nb-4Sn alloy.X-ray diffraction(XRD)texture analysis of the cold-rolled substrate revealed the[302]α″//ND texture component,while analysis of the recrystallized substrate showed the[302]α″//ND and[110]α″//ND components.Theβ-phase texture could not be directly measured by XRD,but the presence of the[111]β//ND texture component was successfully predicted by considering the orientation relationship between theα″andβphases.Nanoindentation measurements showed that the elastic modulus of the cold-rolled substrate(63GPa)was lower than that of the recrystallized substrate(74GPa).Based on the available literature and the results presented here,it is suggested that this difference is caused by the introduction of crystal defects during cold deformation.The combined nanoindentation/EBSD analysis showed that the nanoindentation results are not affected by crystal orientation.LSM of the deformed alloy produced changes in hardness,elastic modulus and crystallographic texture similar to those produced by recrystallization heat treatment,creating a stiffness gradient between surface and substrate.

Microstructure,texture evolution and mechanical properties of cold rolled Ti-32.5Nb-6.8Zr-2.7Sn biomedical beta titanium alloy

Ti-32.5 Nb-6.8 Zr-2.7 Sn（TNZS,wt%） alloy was produced by using vacuum arc melting method,followed by solution treatment and cold rolling with the area reductions of 50% and 90%.The effects of cold rolling on the microstructure,texture evolution and mechanical properties of the experimental alloy were investigated by optical microscopy,X-ray diffraction,transmission electron microscopy and universal material testing machine.The results showed that the grains of the alloy were elongated along rolling direction and stress-induced α＇＇ martensite was not detected in the deformed samples.The plastic deformation mechanisms of the alloy were related to {112} 111 type deformation twinning and dislocation slipping.Meanwhile,the transition from γ-fiber texture to α-fiber texture took place during cold rolling and a dominant {001} 110α-fiber texture was obtained after 90% cold deformation.With the increase of cold deformation degree,the strength increased owing to the increase of microstrain,dislocation density and grain refinement,and the elastic modulus decreased owing to the increase of dislocation density as well as an enhanced intensity of {001} 110α-fiber texture and a weakened intensity of {111} 112γ-fiber texture.The 90% cold rolled alloy exhibited a great potential to become a new candidate for biomedical applications,since it possesses low elastic modulus（47.1 GPa）,moderate strength（883 MPa） and high elastic admissible strain（1.87%）,which are superior than those of Ti-6 Al-4 V alloy.

末道次冷轧变形量对Al-Mg-Si-Cu合金织构和力学性能的影响

通过X射线衍射、电子背散射衍射技术和拉伸测试等研究了末道次冷轧变形量对汽车车身板用Al-Mg-Si-Cu合金板材织构、晶粒形貌和力学性能的影响。结果表明:在成分和冷轧后固溶处理工艺相同的情况下,织构是决定Al-Mg-Si-Cu合金板材力学性能的主要因素。晶粒尺寸最大的33%试样反而获得了最高的抗拉强度和较低的屈强比。这是因为减小末道次冷轧变形量可以降低固溶及预时效处理状态下板材Cube和Cube+ND_(20)织构的含量,从而减少立方型织构对板材强度的损害。而末道次大变形量冷轧会促进再结晶时Copper、S和Brass织构向Cube和Cube+ND_(20)织构的转变,并抑制S织构转变成R织构,在实际生产中应当避免。

冷轧加工率对5182-O铝合金汽车板性能和织构的影响

目的研究冷轧变形量对5182铝合金汽车板力学性能、塑性应变比、金相及织构的影响,系统解释5182铝合金汽车板的强化机理和成形性变化机理。方法采用X射线衍射仪、金相显微镜和万能拉伸试验机研究不同冷轧加工率下5182-O铝合金的力学性能和显微组织变化规律。结果50%和75%冷轧加工率的样品强度无明显差异,25%冷轧加工率的样品偏低约3 MPa。塑性应变比加权平均值rm随冷轧加工率的增大而减小,几乎呈线性关系,塑性应变比各向异性度Δr则先减小后增大,延伸率和应变硬化指数则无明显差异。当冷轧加工率从25%增至50%时,平均晶粒尺寸减小了约24%,当冷轧加工率从50%增至75%时,平均晶粒尺寸仅减小了1~2μm。不同冷轧加工率下的5182铝合金连退再结晶后均表现出较弱的织构强度,Cube织构未占主导地位,仍保留了较多的轧制织构。S、Copper和Brass织构的体积分数随冷轧加工率的增大而有所减小,Goss和Q织构的占比有所增大,Cube织构的占比则变化不大。结论冷轧加工率影响了5182-O铝合金汽车板连退后的晶粒尺寸,进而改变了强度。晶粒尺寸和屈服强度的关系符合经典Hall-Petch以及新Hall-Petch关系式。受不同再结晶形核机制竞争关系的影响,轧制织构随冷轧加工率的增大而稍有减少,导致45°方向的塑性应变比和rm逐渐减小,Δr则先减小后增大。

3104铝合金再结晶织构的研究

应用取向分布函数(ODF)研究和分析了3104铝合金经不同工艺退火后的再结晶织构。结果表明:3104铝合金,形变织构由C{112}<111>,B{110}<112>,S{123}<634>织构组分组成;退火温度和保温时间对3104铝合金再结晶织构有重要影响,在低温短时退火时立方织构取向密度较弱,但随温度升高和保温时间的延长,立方织构取向密度逐渐增加,在经350℃60min,400℃60min和450℃15min等温退火后,再结晶基本完成,立方织构取向密度在400℃保温60min退火时达到最大,约为10级,但仍保留有少量冷轧织构;随着退火温度的升高,第二相粒子Al6(Fe,Mn)和Al(Fe,Mn)Si在再结晶过程中起到了粒子促进形核作用(PSN)。

预先热处理对6111铝合金冷轧及再结晶织构的影响

采用取向分布函数(ODF)法研究了预先热处理对6111铝合金的冷轧和再结晶织构组态的影响。结果表明:预先热处理因改变基体的成分和第二相的析出状态而显著影响6111铝合金的形变织构和再结晶织构;热轧板不经预处理而直接冷轧,其再结晶织构主要由绕法向旋转了15°的立方取向(Cube+ND15)和{011}〈111〉取向构成;冷轧前进行过时效处理,其再结晶织构主要由绕法向旋转了20°的立方取向(Cube+ND20)和{011}〈122〉取向构成;冷轧前进行固溶处理会显著提高冷轧织构中Brass和Goss组分的取向密度,再结晶织构明显弱化,而且Cube+ND20组分绕法方向(ND)产生很大的漫散,接近于{001}〈UVW〉纤维织构。

2E12铝合金在冷轧和退火过程中织构和显微组织的演变

采用取向分布函数(ODF)和背散射电子衍射技术(EBSD)研究冷轧和退火对2E12铝合金织构的影响,并采用透射电镜(TEM)分析亚结构在冷轧与退火过程的演变规律。结果表明:2E12合金热轧板在冷变形过程中,随着冷轧变形量从40%增加到80%,黄铜织构(Brass){011}?211?和S型织构{123}?634?逐渐增多,立方织构(Cube){001}?100?明显减少。在退火过程中残留的立方取向亚晶通过晶界迁移吞噬周围的S取向亚晶而优先长大。在470℃退火0.5h后,立方织构(Cube){001}?100?成为主要取向,其体积分数为36%。在相同的退火工艺条件下,随着冷变形量的增加,退火后2E12合金的立方织构体积分数增大。

6111铝合金在冷轧过程中织构的变化

采用取向分布函数(ODF)分析并研究了6111铝合金在冷轧过程中织构的演变及轧制工艺对冷轧织构的影响.结果表明,6111铝合金冷轧后,主要轧制织构组分均为Copper织构组分、S织构组分和Brass织构组分;冷轧过程中,在一定条件下会产生较强的旋转立方织构,而且继续轧制时,随着轧板的减薄,旋转立方织构会迅速减弱而Copper,Brass,S等正常轧制织构组分迅速增强.此外,在总轧制形变量相同的条件下,随着道次压下率的提高,轧制织构减弱.

轴向取向组织BFe10-1-1管材冷轧加工过程中组织、织构与力学性能的变化

采用热冷组合铸型（HCCM）水平连铸技术制备具有轴向取向组织的BFe10-1-1管材，对管材进行冷轧加工，研究管材的组织、织构与性能的变化。结果表明：HCCM水平连铸管材不需铣面便可直接冷轧加工；无中间退火的累积冷轧变形量可达80％以上；冷轧管表面质量好，轧制过程中无裂纹、裂口和飞边等缺陷；随着变形量的增加，取向组织晶粒内一次枝晶主干间距逐渐减小，由铸态的100-200μm减小到变形量60％时的10-20μm；当冷变形量为60％时，组织中可观察到剪切带，当冷变形量为80％时，组织呈波浪状，枝晶、晶界很难辨认；冷轧过程中管材由铸造织构（主要取向{012}（621））、经过渡型织构{012}（100）（变形量为20％）和{057}〈372〉（变形量为40％），转变为变形量为60％时的Cube织构，当变形量为80％时转变为G织构；随着变形量的增加，冷轧管的抗拉强度和硬度分别由铸态的234MPa和70HV增加至变形量80％时的372UPa和152HV，伸长率由铸态的46．5％降低至80％变形量时的13％。

拉伸与轧制预变形对2519A铝合金组织与力学性能的影响

通过硬度测试、拉伸测试、透射电镜分析以及织构测试等手段,研究拉伸和冷轧两种不同预变形方式对2519A铝合金165℃时效后组织与力学性能的影响。结果表明:适当的变形量均使θ′相尺寸细小、密度增加,而变形量过大使θ′相分布变得较不均匀,合金强度提高不大,而塑性降低;6%拉伸预变形和7%冷轧预变形使合金板材峰值时效抗拉强度、屈服强度和伸长率分别为472MPa、404MPa、15.6%和472MPa、417MPa、9.4%,二者的抗拉强度基本相同,但前者的屈服强度低、塑性高;两种预变形方式下板材织构类型相同,取向密度无明显差别;合金板材屈服强度和伸长率的差别由第二相θ′相的数量、尺寸和分布所确定。