菜单
  
    摘要超细晶材料具有优异的性能,其制备方法通常包括高压扭转法、叠层轧合技术、反复折皱-压直法、等径角挤压变形法及多向锻压法等。其中 ECAP变形技术由于作为许多材料获取超细晶组织以来提高其力学性能的的方便手段,因而近年来受到了极大的关注。如今对纯铜 ECAP 加工变形领域的研究已经取得许多进步和成果。然而,尽管在该领域已有大量研究,与 ECAP 的其他方面相比,对纯铜ECAP 变形态热处理过程中织构的变化的了解却甚少。本毕业论文研究了无氧纯铜(纯度 99.98%)在采用 Bc 方式经过 8 道次 ECAP 加工变形及随后热处理后的显微组织和织构的变化。在 ECAP 变形后,试样分别置于不同温度下和不同时间变量条件退火处理。变形状态和退火后状态的试样经过 EBSD、TEM以及硬度测试。其织构的形成和显微组织的变化被记录下来并与冷轧材料中织构的形成和显微组织的变化进行了对比。我们对观察的现象进行了分析,认为这些现象与再结晶及晶粒生长机理有关。结果显示在随后的退火中,织构和显微组织的变化与非连续再结晶有关。该研究说明 ECAP加工后的纯铜具有非常低的热稳定性。19199
     关键词  超细晶  等径角挤压  织构  再结晶
    Title   The Preparation of Ultra-fine Grained Copper and the Study in its Thermal Stability
     Abstract
    Ultra-fine grain materials have excellent properties, and the methods of
    preparation  usually include  High Pressure Torsion、Accumulative Roll
    bonding、Repetitive Corrugation  and Straightening、Equal Channel Angular
    Pressing、Multi-directional Forging  etc. ECAP deformation  received great
    attention in recent years  since  it     provides  a  convenient way to  obtain
    ultra-fine grain for many materials to  improve the  
    mechanical properties. Recently much progress and achievements has been
    made in the field of ECAP deformation of pure copper. However, although
    a number of studies  have  been made  in the field, compared with other aspects
    of ECAP,  Comparatively little is known about the mechanisms of
    microstructural change during annealing. Microstructure and texture
    evolution of pure copper (99.98%) after equal-channel angular pressing
    (ECAP) with route Bc up to 8 passes and subsequent heat treatment were
    investigated.After ECAP  deformation, samples under different temperatures
    and different annealing-treatment time  are studied.  The deformed and
    annealed states were characterized by X-ray pole figures, electron back
    scatter diffraction (EBSD), TEM and microhardness tests. The formation of
    the texture and the change of microstructure were recorded and compared
    with texture of cold rolled material formation and the changes  of
    microstructure were compared. We  analyzed the phenomenon of
    observation  and think that these phenomenon  related to the
    recrystallization and grain growth mechanism. Results show that in the
    subsequent annealing, texture and microstructure changes related to the
    discontinuous recrystallization.  The study shows that after ECAP
    processing  pure copper has a very low thermal stability.  
    Keywords Ul tra-fine grain  ECAP  Texture  Recrystalization
    目录
    1  绪论    1
    1.1  引言  .  1
    1.2  剧烈塑性变形  .  1
    1.2.1 高压扭转法  .  2
    1.2.2 反复折皱-压直法    3
    1.2.3 ECAP 变形法.  3
    1.3  纯铜 ECAP 变形的组织与性能特点    5
    1.4  ECAP 超细晶铜的研究现状.  7
  1. 上一篇:利用相场法估算板条马氏体内部最大位错密度
  2. 下一篇:高能球磨装置设计与实验验证
  1. 溶胶—凝胶法制备多晶钇铝石榴石纤维制备

  2. 非晶MgZnO薄膜制备及其光电探测器研究

  3. 镁基非晶储氢合金的取代...

  4. 4H-SiC晶体中Shockley层错的TEM观察

  5. ECAP辅助304奥氏体不锈钢的晶界工程研究

  6. 大塑性变形对铝合金的晶间腐蚀性能的影响

  7. 超细晶AZ31镁合金低周疲劳性能研究

  8. 乳业同业并购式全产业链...

  9. 大众媒体对公共政策制定的影响

  10. 酸性水汽提装置总汽提塔设计+CAD图纸

  11. 河岸冲刷和泥沙淤积的监测国内外研究现状

  12. 十二层带中心支撑钢结构...

  13. 当代大学生慈善意识研究+文献综述

  14. java+mysql车辆管理系统的设计+源代码

  15. 电站锅炉暖风器设计任务书

  16. 杂拟谷盗体内共生菌沃尔...

  17. 中考体育项目与体育教学合理结合的研究

  

About

751论文网手机版...

主页:http://www.751com.cn

关闭返回