• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >DENSIFICATION OF SHOCK CONDITIONED CERAMIC POWDER BY RATE CONTROL SINTERING.
【24h】

DENSIFICATION OF SHOCK CONDITIONED CERAMIC POWDER BY RATE CONTROL SINTERING.

机译：通过速率控制烧结来增稠陶瓷粉末的增稠作用。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Shock-conditioning of ceramic particulates--first introduced in 1966 by Bergmann and Barrington--is known to introduce excess internal energy (plastic deformation), as evidenced by residual strain and crystallite size reduction, and subsequently to enhance sinterability. These effects have been reconfirmed in this study of a fine, pure alumina oxide powder. However, the main sequence experiment undertaken in this work, spanning the nominal shock pressure range 5.1-10.7 GPa, clearly shows, apparently for the first time, the adverse consequences of bimodal morphology resulting from overcompaction during shocking. In overcompacted powders, uncontrolled grain growth occurs during the late intermediate and early final stages of sintering, resulting in very coarse-grained microstructure. This research has been directed toward identification and optimization of the parameters affecting the process of (1) shock conditioning, and (2) intermediate (post-shock) processing of the powders. In a broader sense, it has also been directed toward identifying the mechanisms responsible for shock-induced enhancement of sinterability of ceramic materials.;In this paper, the experimental findings are reviewed; the adverse effects of excessive shock compaction on the densification kinetics and microstructural development are considered; shock-induced morphological alteration and/or aggregation of the powders is examined; competing thermally-activated, rate-sensitive, morphology-dependent processes (recrystallization, grain growth) which could impede sintering and alter final microstructures are identified; and based on controlled atmosphere precision-digital dilatometry, some examples of enhanced sinterability, due to shocking conditioning per se (reasonably free of confounding morphological effects) are presented.;A well-known and sinterable grade of alumina (CR-10 Al(,2)O(,3), from Baikowski International) was chosen as a high-purity research grade material ((TURN) 99.98% Al(,2)O(,3), (TURN) 10 m('2)/g, 0.13 (mu)m). It was subjected to nominal plane strain shock conditioning in precompacted, steel encapsulated disk form by an explosively-driven flyer plate. After removal from the recovery fixture, the shocked powders were comminuted and reconstituted as small (9.5 mm diameter) cylindrical compacts (D(,0) (TURN) 0.62). In supporting studies of statically-compacted powder, pressure was applied hydrostatically (to 5.5 GPa, static) using a modified belt type high pressure apparatus (courtesy of NIRIM, Japan).
机译：陶瓷颗粒的冲击调节-由Bergmann和Barrington于1966年首次提出-已知会引入过量的内部能量（塑性变形），这通过残余应变和微晶尺寸减小得以证明，并随后提高了烧结性。在这项研究中，已经证实了细粉，纯氧化铝粉末的这些作用。然而，这项工作所进行的主序列实验跨越了标称的冲击压力范围5.1-10.7 GPa，这显然是第一次清楚地表明了在冲击过程中由于过度压缩而导致的双峰形态的不利后果。在压实过度的粉末中，在烧结的中后期和早期最终阶段会发生不受控制的晶粒长大，从而导致晶粒非常粗大的微观结构。这项研究致力于确定和优化影响（1）冲击调节和（2）粉末的中间（冲击后）加工过程的参数。从更广泛的意义上讲，它还旨在确定引起冲击引起的陶瓷材料可烧结性增强的机理。考虑过大的冲击压实对致密化动力学和微观结构发展的不利影响；检查了冲击引起的粉末形态变化和/或聚集；确定了竞争性的热活化，速率敏感，依赖形态的过程（重结晶，晶粒生长），这些过程可能会阻碍烧结并改变最终的微观结构；并基于可控气氛精密数字膨胀法，给出了一些因本身具有震荡条件（合理地没有混杂的形态学效应）而提高了可烧结性的例子。;一种众所周知的可烧结等级的氧化铝（CR-10 Al（，来自Baikowski International的2）O（，3）被选作高纯度研究级材料（（TURN）99.98％Al（，2）O（，3），（TURN）10 m（'2）/ g ，0.13μm）。它由爆炸驱动的飞轮板以预压缩的钢封装圆盘形式进行名义平面应变冲击调节。从回收固定装置中取出后，将粉碎的粉末粉碎并重新制成小（9.5毫米直径）的圆柱状压块（D（，0）（转向）0.62）。在对静态压粉的研究中，使用改进的带式高压装置（由日本NIRIM提供）对流体施加静压（至5.5 GPa，静压）。

著录项

  • 作者

    KIM, KYUNG YONG.;

  • 作者单位

    North Carolina State University.;

  • 授予单位 North Carolina State University.;
  • 学科 Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 1983
  • 页码 117 p.
  • 总页数 117
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号