• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Materials Science and Engineering >Observation of low temperature superplasticity in an ultrafine grained AA6063 alloy
【24h】

Observation of low temperature superplasticity in an ultrafine grained AA6063 alloy

机译：超细晶粒AA6063合金中低温超塑性的观察

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

In the present work, mechanical properties and low temperature superplasticity behavior of a nano/ultrafine grained AA6063 alloy fabricated by accumulative roll bonding (ARB) was investigated. To that end, superplasticity was evaluated at various deformation temperatures and for different strain rates in an AA6063 alloy ARBed up to seven cycles. Results showed that the nano/ultrafine grained AA6063 alloy exhibited an excellent low temperature superplasticity (low peak stress of 40 MPa and maximum elongation up to 270%) at 300 °C & 350 °C and under the nominal strain rates of 5 × 10~(-3)s~(-1), 5 × 10~(-2)s~(-1) 5 × 10~(-1)s~(-1). The best condition of superplasticity, together with a stable microstructure, was obtained at 300 °C. Results also showed that at the deformation temperature of 250 °C, and under all strain rates, the elongation does not exceed 95%, hence for the absence of proper superplasticity at this temperature. It was found that although high amount of total elongation can be obtained at 350 °C and under low strain rates of 5 × 10~(-2)s~(-1), 5 × 10~(-3)s~(-1), the microstructural instability of these cases made them unsuitable for industrial applications. During superplastic deformation, low angle grain boundaries (LAGBs) gradually transformed into high angle grain boundaries (HAGBs) to sustain grain boundary sliding and to accommodate dynamic recovery. Constitutive equations were built, and strain rate sensitivity, as well as apparent activation energy variation were calculated. Using Zener-Hollomon parameter, the dominant hot deformation mechanism(s) in each deformation temperature was explained in conjunction with work hardening, dynamic recovery, dynamic recrystallization (DRX) and grain boundary sliding. As well, results indicated that the grain boundary sliding was the predominant deformation mechanism at 350 °C. Finally, a truly superplastic regime was achieved at the temperature of 300 °C and for the strain rate of 5 × 10~(-2) s~(-1).
机译：研究了通过累积辊粘合（arb）制造的纳米/超细颗粒AA6063合金的机械性能和低温超塑性性能。为此，在各种变形温度下评估超塑性，并且在AA6063合金中的不同应变速率均达到七个循环。结果表明，纳米/超细颗粒AA6063合金在300℃和350℃下表现出优异的低温超塑性（低峰值应力，最大伸长量为270％），并在5×10的标称应变率下（-3）S〜（-1），5×10〜（-2）S〜（-1）5×10〜（-1）S〜（-1）。在300℃下获得超复制性的最佳超塑性条件，以及稳定的微观结构。结果还表明，在250℃的变形温度下，在所有应变速率下，伸长率不超过95％，因此在这种温度下没有适当的超塑性。发现尽管在350℃并在5×10〜（-2）S〜（-1）的低应变率下可以获得大量的总伸长率，但是在5×10〜（-2），5×10〜（-3）s〜（ - 1），这些情况的微观结构不稳定使它们不适合工业应用。在超塑性变形期间，低角度晶界（LAGBS）逐渐转变为高角度晶界（HAGBS）以维持晶界滑动并适应动态恢复。构成结构剖面方程，并计算了应变速率灵敏度，以及表观激活能量变化。使用ZENER-HOLLOMON参数，结合工作硬化，动态回收，动态再结晶（DRX）和晶界滑动，解释每个变形温度中的主导热变形机制。同样，结果表明，晶界滑动是350℃的主要变形机制。最后，在300°C的温度和5×10〜（-2）S〜（-1）的应变速率下实现了真正的超塑性。

著录项

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