Study on micro-crack propagation behavior of single-crystal α-Ti under shear stress based on molecular dynamics

2020 ◽  
Vol 25 ◽  
pp. 101622
Author(s):  
Junye Li ◽  
Liguang Dong ◽  
Xiang Zang ◽  
Xinming Zhang ◽  
Weihong Zhao ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Shear Stress ◽  
Crack Propagation ◽  
Single Crystal ◽  
Propagation Behavior ◽  
Crack Propagation Behavior

scholarly journals Crack Propagation Behavior of a Ni-Based Single-Crystal Superalloy during In Situ SEM Tensile Test at 1000 °C

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1047
Author(s):  
Wenxiang Jiang ◽  
Xiaoyi Ren ◽  
Jinghao Zhao ◽  
Jianli Zhou ◽  
Jinyao Ma ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Tensile Test ◽  
Single Crystal ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Single Crystal Superalloy ◽  
Propagation Path ◽  
Propagation Behavior ◽  
Crack Propagation Behavior

An in situ scanning electron microscope (SEM) tensile test for Ni-based single-crystal superalloy was carried out at 1000 °C. The stress displacement was obtained, and the yield strength and tensile strength of the superalloy were 699 MPa and 826 MPa, respectively. The crack propagation process, consisting of Model I crack and crystallographic shearing crack, was determined. More interestingly, the crack propagation path and rate affected by eutectics was directly observed and counted. Results show that the coalescence of the primary crack and second microcrack at the interface of a γ/γ′ matrix and eutectics would make the crack propagation rate increase from 0.3 μm/s to 0.4 μm/s. On the other hand, crack deflection decreased the rate to 0.05 μm/s. Moreover, movement of dislocations in front of the crack was also analyzed to explain the different crack propagation behavior in the superalloy.

scholarly journals Investigation of the Blast-Induced Crack Propagation Behavior in a Material Containing an Unfilled Joint

2020 ◽  
Vol 10 (13) ◽  
pp. 4419
Author(s):  
Peng Xu ◽  
Renshu Yang ◽  
Yang Guo ◽  
Zhicheng Guo
Keyword(s):  
Shear Stress ◽  
Stress Concentration ◽  
Crack Propagation ◽  
Wing Crack ◽  
Reflected Wave ◽  
Propagation Behavior ◽  
Dilatational Wave ◽  
Propagating Crack ◽  
Vertical Joint ◽  
Crack Propagation Behavior

This study uses a dynamic caustic technique to study the crack propagation in a medium containing an unfilled joint under blasting. The results show that for the medium containing a vertical unfilled joint, the reflected dilatational wave from the joint tends to suppress both the K I d and the velocity of the opposite propagating crack. However, for the medium containing an oblique joint, the reflected wave from the joint increases K II d , and induces the opposite propagating crack deflect from its original path. Compared with the medium with a vertical joint, the wing cracks are more easy to initiate at the oblique joint where a significant stress concentration is formed under the diffraction of the blast wave. Combined with numerical results, it is found that the wing crack deflects in the clockwise direction when the shear stress was negative, and it turns to counterclockwise when the shear stress was positive.

Sign in / Sign up

Export Citation Format

Share Document