Microhole Forming and Creep Behavior of Fe-Based Nanocrystalline Alloys under Laser Dynamic Impact
Microhole Forming and Creep Behavior of Fe-Based Nanocrystalline Alloys under Laser Dynamic Impact
复制标题
激光动态冲击下铁基纳米晶合金的微孔形成及蠕变行为
DOI：
10.1002/adem.201901361
复制
发表时间：
2020
影响因子：
3.6
通讯作者：
Wang Xiao
中科院分区：
文献类型：
--
作者：
Liu Huixia;Cui Jiankun;Wang Lei;Ma Youjuan;Wang Xiao
鉴于铁基纳米晶合金在室温下难以成形，本研究采用软膜作为柔性微冲头，实现了铁基纳米晶合金箔在激光冲击下的微孔成形。研究了激光能量和软膜厚度对工件成形精度的影响，重点研究了工件的断口特征和蠕变行为。结果表明，随着激光能量的增加，成形精度提高。断裂面包括滑移区和断裂区，断裂区表面分布有大量的熔滴和熔体区。这一特征表明，工件在宏观尺度上表现为脆性断裂，在微观尺度上表现为塑性断裂。工件的蠕变行为包括瞬态蠕变和稳态蠕变。随着蠕变时间的延长，应力指数达到一个稳定状态。随着载荷的增加，应力指数也随之增大，表现出明显的最大载荷依赖性。
Given the difficulty of forming Fe‐based nanocrystalline alloys at room temperature, this study uses soft film as a flexible micropunch to realize the formation of microholes in Fe‐based nanocrystalline alloy foil under laser impact. The effect of laser energy and soft film thickness on forming accuracy of the workpiece is studied, particularly fracture surface characteristic of the workpiece and the creep behavior of the workpiece. It is found that with increased laser energy, forming accuracy is improved. The fracture surface comprises sliding and fracture regions, and a large number of melt droplets and melt zone are distributed on the surface of the fracture region. This feature indicates that the workpiece exhibits brittle fracture in macroscopic scale and exhibits plastic fracture in the microscopic scale. The creep behavior of the workpiece comprises transient creep and steady state creep. With the extension of creep time, the stress exponent reaches a stable state. With the increase in load, the stress exponent also increases, which shows the obvious maximum load dependence.