共查询到20条相似文献,搜索用时 109 毫秒
1.
CHEN Yang TIAN Ni ZHAO Gang LIU Chun-ming ZUO Liang . School of Materials Metallurgy Northeastern University Shenyang China . School of Materials Chemical Engineering Liaoning Institute of Technology Jinzhou China 《中国有色金属学会会刊》2007,(3)
The texture evolution and lattice rotation in Al alloy 6111 with an initial {001} <110> component during symmetrical and asymmetrical rolling were investigated by means of orientation distribution function(ODF). The results show that the as-rolled initial {001}<110 > entation evolves into not only the copper orientation but also all the other orientations along the β fiber, including the brass orientation, by lattice rotation around special directions. Compared with the symmetrical rolling, the {001}<110 > component in the surface layer on the slower roller side evolves more quickly into the orientations along the β fiber during asymmetrical rolling, while that in the surface layer on the faster roller side evolves more slowly. 相似文献
2.
The crystal plasticity finite element method(CPFEM), which incorporates the crystal plasticity constitutive law into the finite element method, was developed to investigate the rolling processes of the cubic oriented and Goss oriented Al single crystal. The simulation results show that after rolling the crystal predominantly rotates around the transverse direction(TD) for both orientations. The rotations around the rolling direction(RD) and the normal direction(ND) are negligible. The reduction plays a significant role in the texture evolution. The TD rotation angle increases with increasing reduction. The deformation bands exist in the rolled specimens with the cubic initial orientation. Compared with the cubic oriented specimens, the TD rotation angles in the Goss oriented specimens are very small. 相似文献
3.
This paper reports TiC–(Ni–Cr) metal ceramic alloy(ratio of components 50:50) with nanoscaled components formed in the surface layer and smoothly transformed into the initial inner structure throughout the material under pulsed electron irradiation of the alloy surface. Principal changes in the surface layer are ascribed to the formation of gradient structure leading to the increase in wear resistance of the surface layer, drop of friction coefficient and improvement of specimen bending resistance when stressing on the irradiated surface side. The above changes of tribological and strength properties in the surface layer under pulsed electron irradiation become more apparent with increasing atomic mass of a plasma-forming inert gas. 相似文献
4.
The influence of microstructure stability on the creep properties of single crystal nickel-based superalloys was investigated by means of the measurement of the creep curves and microstructure observation. Results show that the superalloy with 4%(mass fraction)W in Ni-AI-Cr-Ta-Co-5.5%Mo-x%W systems displays a better microstructure stability, but the β phase is precipitated in the superalloy with 6% W during aging. The strip-like μ phase is precipitated to be parallel or perpendicular to each other along the 〈110〉 orientation, and grown into the slice-like morphology along the { 111 } planes. The superalloy with 4%W displays a better creep rupture lifetime under the applied stress of 200 MPa at 982 ℃, but the creep lifetime of alloy is obviously decreased with the increase of the element W content up to 6%. The fact that the μ phase is precipitated in the superalloy with 6% W during applied stress and unstress aging results in the appearance of the poor regions for the refractory elements. This is one of the main reasons for reducing the creep rupture lifetime of the superalloy. 相似文献
5.
The effect of evolution of polycrystalline texture on normal anisotropy coefficient r-value of aluminum alloy sheet was investigated. For this purpose, the textures under different elongation of LF2 aluminum alloy were measured and analyzed. The result indicates that the initial texture of LF2 aluminum alloy has the typical rolling texture, and the main components include Brass {011 } (2H), Copper { 112}(111)and S{ 123}(634). These three main components exhibit different transformation tendencies when the material specimens are stretched along the different direction. Based on Taylor model and Minor Work principle, the normal anisotropy coefficient r-values ofpolycrystalline aluminum alloy under various strain states were calculated. The result indicates that the r-values of LF2 aluminum alloy vary with tensile direction and the amount of deformation. The deformability on rolling direction is superior to the other direction because an enhancement tendency of r0 appears in tension process along rolling direction. 相似文献
6.
Development and application of coupling model of aluminum thin-gauge high-speed casting 总被引:4,自引:0,他引:4
Based on the analyses of aluminum melt flow, solidification, heat transfer during the process of twin-roll casting, a coupling mathematical model of aluminum thin-gauge high-speed casting was developed, which included the casting roller shell. At the same time, Galerkin method was adopted to solve the coupling model. The fluid field and temperature field of aluminum melt in casting zone, the temperature field and thermal stress field of roller shells were simulated by the coupling model. When the casting velocity is 7 m/min, and the thickness of strip is 2 mm, the circumfluent area comes into being in the casting zone, and the mushy zone dominates the casting zone, while the temperature of melt decreases rapidly as it approaches the rollers. The temperature of the roller shell varies periodically with the rotation of roller, and reaches the highest temperature in the casting zone, while the temperature of roller shell decreases gradually as it leaves the casting zone. The difference of thermal stress between the inner surface and outer surface of the roller shell is very large, and the outer surface suffers tensile-compressive stress. 相似文献
7.
By rolling and nitriding processes, 0.23- to 0.3-mm-thick grain-oriented 6.5 wt% silicon steel sheets were produced. The core losses of grain-oriented 6.5 wt% silicon steel at frequencies ranging from 400 Hz to 20 k Hz were lower than that of the grain-oriented 3 wt% silicon steel with the same thickness by 16.6–35.8%. The secondary recrystallization behavior was investigated by scanning electron microscopy, energy-dispersive spectroscopy, and electron backscattered diffraction. The results show that the secondary recrystallization in high-silicon steel sheets develops more completely as the nitrogen content increases after nitriding, secondary recrystallized grain sizes become larger, and the sharpness of Goss texture increases. Because more {110}116 grains in the subsurface and the central layer of the sheets have a lot of 20°–45° high-energy boundaries in addition to Goss grains, {110}116 can be the main component through selective growth during secondary recrystallization when the inhibitor quantity is not enough and inhibitor intensity is weaker. The increases in nitrogen content can increase the inhibitor intensity and hinder abnormal growth of a mount of {110}116 grains and therefore enhance the sharpness of Goss texture. 相似文献
8.
The effect of surface state on the nodular corrosion resistance of Zircaloy-4 alloy was investigated in superheated steam at 500 °C/10.3 MPa by autoclave tests. The microstructures of oxide films on the corroded specimens were observed by TEM and SEM. The results indicate that surface strained layer delays the appearance of nodular spots on the specimen surfaces and improves the nodular corrosion resistance. The columnar grains orientation of the oxide films formed on the specimens with surface strained layer was more consistent than that on the specimens without surface strained layer when a comparison was made on the same orientation of the grain surfaces. Such a kind of oxide microstructure formed on the specimens with surface strained layer can hinder the diffusion of oxygen ions along the grain boundaries and delay the growth of oxide films, therefore retard the formation process of nodular spots. This indicates that the microstructure of the initial oxide films has an important influence on the subsequent growth of the oxide films. 相似文献
9.
Guang-Lei Wang Jin-Lai Liu Ji-De Liu Yi-Zhou Zhou Xu-Dong Sun Hai-Feng Zhang Xiao-Feng Sun 《金属学报(英文版)》2021,34(5):719-728
Stress-rupture properties of a Ni-base Re-containing single-crystal superalloy with three orientations have been tested under 900 ℃/445 MPa. An obvious anisotropy of stress-rupture property is attributed to orientation reliant deformation microstructure. The good strength in [001] orientation is attributed to the rapid multiplication of dislocations active in horizontal channels and later γ' cutting via dislocations pair coupled with anti-phase boundary. The microtwin formation largely limits the strength and plasticity as a result of the continuous shearing across γ/γ' microstructure by {111} 112 slip activated in [011] orientation. The property in [111] orientation results mainly from the lateral cross-slip movements of the screw dislocations within connected matrix channels as well as the precipitate shearing by coplanar dislocations. Microcracks all initially originate from the interdendritic micropores in three orientations. The critical temperature of stress-rupture anisotropy could be increased by a high level of refractory solutes especially Re. 相似文献
10.
The microstructure, texture evolution and spatial orientation distribution during cold rolling and the subsequent annealing as well as formability and ridging of a Sn-bearing ferritic stainless steel under different hot band annealing temperatures were investigated. The four hot bands with annealing temperatures of 900, 950, 1000 and 1050 °C were all cold-rolled to 80% reductions and then were annealed at the same temperature of 900 °C. The results show that optimizing hot band annealing process is benefi cial to reduce the amount of {001} 110 grains and weaken the texture intensity, and thus, to reduce ridging and improve formability. In the present study, the fi nal sheets with hot band annealing temperature of 900 °C possess small and inhomogeneous grains with a large amount of {001} 110 orientations, which deteriorates the formability and increases the ridging. In comparison, the fi nal sheets with hot band annealing temperature of 950 °C are comprised of uniform and equiaxed 111//ND(ND: normal direction) recrystallized grains with a high texture intensity favorable for the improvement in r value and surface quality. However, when hot band annealing temperature further increases to 1000 and 1050 °C, it shows a sharp decrease in r value and a remarkable increase in ridging as a result of a reduction in γ-fi ber texture intensity and an increase in grain size in the fi nal sheets. Suitable controlling and optimizing hot band annealing process is essential to improve the formability and reduce the ridging. 相似文献
11.
12.
柱状晶对Fe-3%Si电工钢冷轧织构演变规律的影响 总被引:1,自引:0,他引:1
Fe-3%Si电工钢铸锭中普遍存在柱状晶,其晶体学及形状各向异性对随后的热轧、冷轧及退火织构产生很大的影响.利用xRD与EBSD技术对长轴分别平行于轧面法向(ND),轧制方向(RD)和横向(TD)的柱状晶冷轧样品的织构及组织进行了研究,并对晶界的特殊作用进行了分析.结果表明,中等压下量下,3种柱状晶样品具有不同程度的{001}织构遗传性,即3种样品均不同程度的摆脱了{111}线织构的形成;柱状晶长轴平行于ND和TD时,{001}取向在冷轧时得到大的保留;柱状晶长轴平行于RD时,得到最强的{111}〈112〉织构;柱状晶长轴平行于TD时,冷轧组织中旋转立方织构及{111}〈110〉织构较强.此外,3种样品的织构均表现出由立方→{001}〈130〉→{113}〈251〉的过渡路径,与等轴多晶样品沿α线和γ线转动的路径不同.不同方向的柱状晶晶界对冷轧变形过程中晶粒转动的作用不同,但因晶粒尺寸大而作用有限,且与初始取向相关. 相似文献
13.
1 INTRODUCTIONLargequantityoftheAl Mn Mgalloy 310 4isusedinthemanufactureofaluminumbeverage .Muchattentionwaspaidtothecontroloftextureandearinginthedeepdrawingstagesofmanufacture .Thetex tureinthecanstockwasextensivelyinvestigated .Oneearingofaluminumalloyisverycloserelatedtothetexture ,agoodassociationofthetexturescompo nentsearingdropsobviously ,inthissituationthe 4 foldearingat 0°/90°andearingat± 4 5°occursto gether[15] .Theappearanceof 4 foldearingat 0°/90°isduetothecubetext… 相似文献
14.
横轧3105铝合金织构演变的定量分析 总被引:1,自引:0,他引:1
采用X射线衍射仪研究3105铝合金在横轧过程中织构的演变.结果表明:3105铝合金热轧板材具有强的β纤维轧制织构,在横轧过程中B'{110}<111>、S"{123}<17229>和C"{112}<110>取向是不稳定的,它们将逐渐向新的坐标系中β纤维的位置旋转;随横轧压下量增大,C(和S(取向强度快速降低,B(取向强度先增加后降低,而β纤维轧制织构的强度逐渐增加;β纤维和剩余组分织构体积分数的变化与轧制真应变的关系遵循Avrami方程,强的初始B'、S"和C"织构显著地提高了β纤维织构的形成速率. 相似文献
15.
In high purity aluminium two different types of hot band textures were produced by changing the final hot rolling temperatures. The texture of the hot bands was found to be inhnmogeneous through thickness. The strong preferred orientation of {001}<110> developed in the surface layer of the hot band which had been rolled at the higher finishing temperature. For the lower finishing temperature sample, the cold rolling type of texture was formed in the hot band. The cold rolling texture was dependent on the initial hot rolling texture. The hot band which had strong {001}<110> at the surface layer led to the maximum orientation density at {44 11}<11 11 8> after the subsequent cold rolling. Preferred orientations near {123}<634> in the hot band caused the maximum at {123}<634> in the cold rolling texture. The experimental results were discussed based on the simulation test of deformation texture in which the rotation of orientations was calculated from the Taylor model. In this calculation, the strain state of the deformation zone in the rolling gap is assumed to vary with shears induced from the geometry and the friction. 相似文献
16.
异步轧制高纯铝箔冷轧织构沿板厚的分布规律 总被引:6,自引:1,他引:6
通过异步轧制,研究了高纯铝箔冷轧织构沿板厚的分布规律。在异步轧制下,快、慢速辊侧之间的各中间层的织构类型不同。速比为1.28,形变量为99.2%时,随厚度的增加,呈现出极有规律的变化:(100)丝织构含量近线性减少,而(112),(102),(123)丝织构含量近线性增加。当形变量为99.2%时,在不同速比下(400)丝织构含量沿厚度变化趋势不同:速比1.28时,呈现出近线性递减;速比1.17和1.06时,总的趋势也是递减,且在厚度d=0.04mm处有最小值。 相似文献
17.
The shear textures developed in the surface layer by rolling procedures consist mainly of {001}<110> and {111}<uvw> orientations
in FCC metal sheets, but the orientation components of shear textures vary with the rolling conditions. That is, either a
single orientation component or a mixture of components can be developed depending on the rolling conditions. The purpose
of this study is to analyze the various shear deformation textures in rolled FCC metal sheets. 相似文献
18.
A. A. Redikul’tsev M. L. Lobanov G. M. Rusakov L. V. Lobanova 《The Physics of Metals and Metallography》2013,114(1):33-40
After the primary recrystallization of a preliminarily deformed (110)[001] single crystal, the texture also has the preferred (110)[001] orientation. Furthermore, the texture contains weak orientations, a major part of which is formed at the sample surface and can be described by a spectrum of scattered orientations {120}〈210〉…{351}〈103〉. A further heating leads to two concurrent processes taking place in the samples, i.e., the normal growth of Goss grains and secondary recrystallization. Abnormally grown crystals are represented by a quartet of orientations related with the initial Goss orientation by a rotation around [011], [01 $\bar 1$ ], [101], and [10 $\bar 1$ ] axes at an angle of ~30°. The crystallographic relationship between the initial and final grain orientations can be explained by their closeness to special misorientations as follows: Σ9, Σ19a, Σ27a, and Σ33a (rotation around 〈110〉 axes to close angles). 相似文献
19.
20.
采用光学显微镜、X射线衍射仪及扫描电镜对含稀土无取向硅钢整个生产流程中的显微组织及织构演变进行研究。结果表明,热轧板在厚度方向上有显著的分层,即表层的再结晶层、过渡层、中间层的变形组织层,其织构主要包含铜型、黄铜型织构;正火后晶粒发生了完全再结晶,织构类型相对热轧基本无变化,但强度减弱;两次冷轧后的组织均为纤维组织,形成了以α、γ线性织构为主的织构类型,还出现了强度较高的反高斯织构如{001}<110>、{112}<110>、{111}<110>;脱碳退火后发生部分再结晶,织构相对于冷轧态α、γ线性织构强度均减小;在高温退火阶段晶粒发生再结晶,存在以{111}<112>、{111}<110>为主的γ织构,以及{100}<001>织构。 相似文献