Deformation microstructure characteristics of commercial pure titanium sheet induced by laser shock forming

被引：0

作者：

Luo, Xinmin ^{[1
]}

Zhao, Guangzhi ^{[1
]}

Yang, Kun ^{[1
]}

Chen, Kangmin ^{[1
,3
]}

Zhang, Xiaoning ^{[1
]}

Zhang, Yongkang ^{[2
]}

Luo, Kaiyu ^{[2
]}

Ren, Xudong ^{[2
]}

机构：

[1] School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China

[2] School of Mechanical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China

[3] Analysis and Test Center, Jiangsu University, Zhenjiang, Jiangsu 212013, China

来源：

Zhongguo Jiguang/Chinese Journal of Lasers | 2012年 / 39卷 / 06期

关键词：

Crystalline materials - Stacking faults - Microstructure - Strain rate;

D O I：

10.3788/CJL201239.0603001

中图分类号：

学科分类号：

摘要：

The commercial pure titanium sheet TA2 is continually mould-free laser shock deformed by means of a Nd:glass Q-switched laser setup with 1064 nm wavelength and 20 ns short pulse. The microstructure characteristics of the deformed sheet on whole section are analyzed with the thermo-field emission scanning electron microscope (SEM) and transmission electronic microscope (TEM) respectively. Three main microstructure characteristics are observed based on the stress state in deformed zone. The first is the near nanometer micro-twin gate in the compression strain region, which is thought to be a product composed of high density of stacking faults in the same direction. Due to the inter-actions between neonatal microstructures and the induced third type of internal stress, high density of dislocation networks and/or dislocation cells formed in laser shocked substrate. The second is the inverse-transformed martensite, which is induced by partial shear deformation in the compression zone of laser shock deformed sheet. The third is the local stratified cluster slips along the cleavage direction, induced by the ultra high energy and ultra-high strain rate of laser shock, in the tensile deformed region owing to the increasing of deformation resistance of highly constrained hcp crystalline material. The above-mentioned phenomena can be attributed to the confinement conditions and deformation mode of micro-zone upon laser shock forming, and will result in microscopically inhomogeneous of microstructures and hardness in the deformed section. Therefore, repeated shocking is not conductive to the uniformity of deformation of titanium sheet.

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