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1.
Microstructure,Textures and Deformation Behaviors of Fine-grained Magnesium Alloy AZ31 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Ping YANG Zude ZHAO Xueping REN Shaodong HUANG School of Materials Science Engineering University of Science Technology Beijing Beijing China The th Institute of Chongqing Chongqing China 《材料科学技术学报》2005,21(3):331-337
Channel die compression and initial textures are used to activate different deformation mechanisms in a fine-grained magnesium alloy AZ31. The σ-εcurves, microstructures and, particularly, textures are analyzed to reveal different deformation mechanisms and to compare with those of coarse grained samples. Dominant double-prismatic slip, {1012} twinning and basal slip are detected in three types of samples, respectively, which is similar to those of coarse grained samples. The detrimental effect of shear band formation or {1011} twinning is limited in fine grained microstructure. In addition to the higher flow stress at low temperature an early decrease in flow stress at higher temperature is also found in fine-grained samples in comparison with their coarse-grained counterparts. This softening is ascribed to the early dynamic recrystallization or grain boundary glide. 相似文献
2.
Yu-ichi Yoshizawa Motohiro Toriyama Shuzo Kanzaki 《Journal of the American Ceramic Society》2001,84(6):1392-1394
Texture formation via high-temperature deformation in sintered alumina was investigated. Fine-grained, normal-purity-alumina sintered bodies deformed under stresses up to 80 MPa in a temperature range of 1200°–1300°C. Fine, disklike grains formed in the equiaxial fine-grained matrix during high-temperature deformation and aligned unidirectionally via material flow during deformation. Highly textured sintered alumina bodies were obtained via high-temperature deformation and further annealing. 相似文献
3.
A.S. Argon 《Journal of Computer-Aided Materials Design》1997,4(2):75-98
The development of deformation-induced texture in high-density polyethylene is described from the point of view of a micromechanically based composite computer model of crystalline lamellae associated with attached amorphous layers. The predictions of the model are compared and contrasted with detailed recent experimental observations of this process by WAXS, SAXS, TEM, atomic force microscopy, light microscopy and a whole host of conventional and unconventional means of mechanical probing. A separate set of experiments probing the rate controlling process of chain slip in quasi-single-crystalline nylon-6 are also presented together with implications related to the kinetics of long-range dislocation motion in such highly textured solids. 相似文献
4.
研究浸锌时间对高强度钢丝性能影响。采用GB 8919—2006对19个不同浸锌时间的φ2.78 mm高强度钢丝的抗拉强度、扭转和弯曲进行测试,并对1#、2#、6#、10#、18#试样进行金相组织分析。结果显示:在浸锌时间4 s时试样的抗拉强度为1 946 MPa,17～21 s时抗拉强度降到1 850 MPa,且趋于稳定;在4～5 s时试样扭转值提高到24次,之后基本稳定;在5 s之前试样弯曲值未变化,6 s时弯曲值开始缓慢递减,21 s时试样弯曲值降到12次。金相组织中的回复组织随着浸锌时间增加有明显增多趋势,18#试样中回复组织已经达到80%。随着浸锌时间增加,φ2.78 mm钢丝白色回复组织增大增多,晶粒回复长大使部分加工硬化产生的畸变应力得以消除,内部能量得以释放,钢丝抗拉强度和弯曲逐渐降低,扭转值升高。 相似文献
5.
The formation and evolution of deformation texture in polycrystalline materials are studied by phase-field dynamic model. In addition, the driving force of texture evolution is also discussed. In this model, grains with different orientation are defined by a set of continuous non-conserved order parameter fields. Simulation results show that grains with preferred orientation grow at the expense of those with unfavorable orientations. It is more important that, elastic potentia evolution of texture whether the polycrystalline system rather than elastic energy plays a crucial role in the s subjected to uniaxial stress or shear stress. 相似文献
6.
研究室温下锰的质量分数分别为26%和30%的两种晶粒较粗大的TWIP钢拉断过程中织构的演变规律及孪生弱化〈111〉织构的作用。结果表明,TWIP钢拉伸时形成较强的〈111〉织构,也形成由〈111〉取向晶粒的不同孪晶产生的接近〈100〉的弱织构,从而孪生弱化了〈111〉拉伸织构。粗的奥氏体晶粒促进孪生,从而加速〈111〉织构的弱化。拉伸过程中〈111〉取向的晶粒有利于形变孪生,〈100〉取向的晶粒不利于孪生。锰含量较低的26Mn钢出现少量的形变诱发ε-M,由于ε-M主要从〈111〉取向的形变孪晶内形成,因此也出现择优取向,形成倾转的基面织构,弱化了〈111〉织构。 相似文献
7.
钛合金的突出特点包括比强度高，高温性能好，抗腐蚀性能优异，密度小等。因此，常常应用于其它金属不能满足的产品中。同其他金属一样，钛合金热加工过程中形成织构，进而影响材料的使用性能。由于钛合金存在两相特性，其织构问题尤其复杂。目前随着检测设备的不断发展，国内外钛合金织构的研究也得到了很大的进步。 相似文献
8.
纹理映射算法的改进研究 总被引：1，自引：0，他引：1
纹理映射是真实感图形绘制中的重要组成部分,文中提出的纹理映射算法是在传统映射算法的基础上做了两点改进,由于传统的映射算法在物体的两极易产生纹理汇聚现象,且有明显接缝,故真实感效果不理想。文中将纹理图案做适当的拉伸变换,再做映射的逆变换,利用三角网格对接缝处做匹配,实现了纹理的无缝拼接,并能保持表面的连续性,具有较小的变形 相似文献
9.
分析了双相钢冷变形过程中形变织构的演变规律以及合金元素对双相钢形变织构的影响规律。分析结果表明，虽然存在有少量珠光体，但双相钢冷变形织构与体心立方金属相近；非碳化物形成元素Si的加入对形变织构没有明显的影响；碳化物形成元素Cr和Nb导致形变织构在α取向线的{112}<110>取向位置上的取向密度增强。测试分析了双相退火过程中钢的织构演变规律。结果表明，退火时晶粒的取向将沿着α取向线向γ取向线位置转变，Si或Cr对晶粒取向改变的阻碍作用不明显，微合金元素Nb明显阻碍晶粒取向改变，退火织构仍保持很高的α取向线织构组分。对上述的实验结果进行了理论分析。 相似文献
10.
Analysis of the tensile behavior of a TWIP steel based on the texture and microstructure evolutions 总被引：1，自引：0，他引：1
D. Barbier N. Gey S. Allain N. Bozzolo M. Humbert 《Materials Science and Engineering: A》2009,500(1-2):196-206
The texture and microstructure evolutions of a fine-grained TWIP steel subjected to tensile tests at room temperature were investigated in relation to the mechanical behavior. This steel combines both high ductility and strength owing to the TWIP effect. Also the steel exhibits a high strain hardening rate that evolves according to five stages, which are related to the microstructure and texture evolutions and characteristics. The formation of nano-twins in the initial stage of deformation leads to an increase in strain hardening rate. The development of the pronounced <1 1 1> fiber in the tensile direction sustains mechanical twinning and maintains the strain hardening rate on a high level. The resulting microstructure exhibits several types of twin configurations and sub-boundaries with high misorientations due to intense activities of dislocation glide. The twin volume fraction was estimated to be 9% at the final stage of tensile deformation. The new orientations generated by mechanical twinning do not change considerably the final texture. 相似文献