A discrimination model for crack propagation behavior at the interface of layered composite structures considering loading rate effect

Author(s):  
Runxu Zhang ◽  
Xiaoyu Zhang ◽  
Jianting Kang ◽  
Tianhe Kang ◽  
Bailin Zhang
2005 ◽  
Vol 488-489 ◽  
pp. 717-720 ◽  
Author(s):  
Gui Ying Sha ◽  
Yong Bo Xu ◽  
En Hou Han

The dynamic experiments for the Mg-Li alloys with single phase structure were carried out using the Hopkinson pressure bar. The dynamic crack propagation behavior and fracture mechanism of the alloys were investigated. The results show that the dynamic crack propagation is a deceleration process for the Mg-Li alloys under high loading rate. The fastest crack propagation velocity for Mg-3.3Li alloy is m/s 37 . 1253 , and 935.36m/s for Mg-14Li alloy. Observations of the fracture by SEM reveal that the dynamic fracture surface for Mg-3.3Li alloy mainly appears to be brittle fracture along grain boundaries. Whereas, the Mg-14Li alloy is ductile fracture mode under high loading rate. The main reason for these may be the transformation of hcp→bcc structure and the precipitation of the MgLi2Al and AlLi, as increase of Li in Mg-Li alloy.


Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1047
Author(s):  
Wenxiang Jiang ◽  
Xiaoyi Ren ◽  
Jinghao Zhao ◽  
Jianli Zhou ◽  
Jinyao Ma ◽  
...  

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.


2019 ◽  
Vol 29 (9) ◽  
pp. 1882-1888 ◽  
Author(s):  
Wen-juan CHENG ◽  
Yong LIU ◽  
Da-peng ZHAO ◽  
Bin LIU ◽  
Yan-ni TAN ◽  
...  

2004 ◽  
Vol 264-268 ◽  
pp. 793-796
Author(s):  
Hassan El Attaoui ◽  
Malika Saâdaoui ◽  
Jérôme Chevalier ◽  
Gilbert Fantozzi

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