解决J-整体概念的基本原理,通过多种方法在纳米尺度的现场压力-应变图谱绘制
Michael Meindlhumer1, Markus Alfreider1, Noel Sheshi2
1Department of Materials Science, Montanuniversität Leoben, Leoben, Austria.
概括
研究人员使用纳米级应力和应变映射量化了裂纹传播的J-整数. 这项研究揭示了小规模传统模型的局限性,影响了耐损材料的开发.
科学领域:
- 材料科学 材料科学 材料科学
- 机械工程 机械工程
- 纳米技术 纳米技术
背景情况:
- 材料完整性通常通过在裂纹尖端通过塑料工艺对故障的抵抗来评估.
- J-整数是量化这种阻力的一个关键概念,但在裂尖端的实验验证是具有挑战性的.
研究的目的:
- 通过在传播裂周围使用纳米级应力和应变场来实验量化J整数.
- 在微和纳米尺度上研究传统骨折模型的适用性.
主要方法:
- 使用扫描电子显微镜和同步射线X射线纳米衍射在位纳米级应变和应力映射.
- 测试由纳米晶体FeCrMnNiCo高合金制成的微型骨折样本.
- 通过弹性-塑料有限元素建模进行验证.
主要成果:
- 通过使用实验纳米尺度数据,成功量化了沿着各种路径的J-积分.
- 线性-弹性和弹性-塑料模型在扩散裂附近的应用性有限.
- 在纳米尺度上确定了J-积分的路径独立性的限制.
结论:
- 传统的断裂力学模型将其有效性限制在微米到纳米尺度的裂纹尖端距离.
- 这一发现对先进的耐损坏材料的设计和评估有重大影响.
- 这项研究强调了纳米尺度表征的必要性,以了解材料故障机制.
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