Effect of fibril arrangement on crack trapping in a film-terminated fibrillar interface

2009 ◽  
Vol 47 (23) ◽  
pp. 2368-2384 ◽  
Author(s):  
Jingzhou Liu ◽  
Chung-Yuen Hui ◽  
Anand Jagota
Keyword(s):  
Crack Trapping

scholarly journals The Role of Hydrogen on the Behavior of Intergranular Cracks in Bicrystalline α-Fe Nanowires

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 294
Author(s):  
Jiaqing Li ◽  
Cheng Lu ◽  
Long Wang ◽  
Linqing Pei ◽  
Ajit Godbole ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Nanocrystalline Materials ◽  
Fracture Mechanisms ◽  
Bulk Materials ◽  
Cleavage Process ◽  
Deformation And Fracture ◽  
Dynamics Simulations ◽  
Crack Trapping ◽  
Cleavage Failure

Hydrogen embrittlement (HE) has been extensively studied in bulk materials. However, little is known about the role of H on the plastic deformation and fracture mechanisms of nanoscale materials such as nanowires. In this study, molecular dynamics simulations are employed to study the influence of H segregation on the behavior of intergranular cracks in bicrystalline α-Fe nanowires. The results demonstrate that segregated H atoms have weak embrittling effects on the predicted ductile cracks along the GBs, but favor the cleavage process of intergranular cracks in the theoretically brittle directions. Furthermore, it is revealed that cyclic loading can promote the H accumulation into the GB region ahead of the crack tip and overcome crack trapping, thus inducing a ductile-to-brittle transformation. This information will deepen our understanding on the experimentally-observed H-assisted brittle cleavage failure and have implications for designing new nanocrystalline materials with high resistance to HE.

Multiple Toughening Mechanisms of Laminated Ti-TiBw/Ti Composites Fabricated by Diffusion Welding

2016 ◽  
Vol 848 ◽  
pp. 196-201 ◽  
Author(s):  
Bao Xi Liu ◽  
Lin Geng ◽  
Xiang Lin Dai ◽  
Fu Xing Yin ◽  
Lu Jun Huang
Keyword(s):  
Composite Layer ◽  
Bending Test ◽  
Diffusion Welding ◽  
High Fracture ◽  
Toughening Mechanisms ◽  
Fracture Characteristics ◽  
Three Point Bending ◽  
Interfacial Delamination ◽  
Fracture Ductility ◽  
Crack Trapping

Laminated Ti-TiBw/Ti composites behave a moderate loading capacity and high fracture ductility with non-castropic failure stage under three-point bending test. Fracture characteristics of laminated composites reveal many extrinsic toughening behaviors, such as, interfacial delamination, bucking and crack deflection, and the interfacial delamination is attributed to the weak bonding strength. Many strengthening and toughening mechanisms are presented in the TiBw/Ti composite layer, such as de-bonding effects of TiB whiskers, multi-fracture of TiB whiskers, crack trapping effect and crack bridging effect.

Effects Of Externally Generated Dislocations On Brittleness/Ductility Of Crystals

1995 ◽  
Vol 409 ◽  
Author(s):  
Sinisa DJ. Mesarovic
Keyword(s):  
Dislocation Density ◽  
Slip Plane ◽  
Crack Velocity ◽  
Crack Tip ◽  
Atomic Scale ◽  
Burgers Vector ◽  
Density Dependent ◽  
Crack Trapping ◽  
Trapping Process ◽  
Temperature Crack

AbstractDirect interactions of externally generated dislocations with a moving, non-emitting crack tip, have been investigated. Dislocations of the appropriate Burgers vector, initially residing in a strip ahead of the incoming crack tip, are funneled toward the tip, with their motion restricted to the slip plane. Once drawn into the vicinity of the tip, these dislocations inevitably cause local, atomic scale blunting of the tip. The resulting crack trapping process is modelled, resulting in the temperature, crack velocity, and dislocation density dependent, tip toughness.

Enhanced fracture resistance of thermoset/thermoplastic interfaces through crack trapping in a morphology gradient

Polymer ◽  
2021 ◽  
Vol 218 ◽  
pp. 123497
Author(s):  
Quentin Voleppe ◽  
Wael Ballout ◽  
Pascal Van Velthem ◽  
Christian Bailly ◽  
Thomas Pardoen
Keyword(s):  
Fracture Resistance ◽  
Crack Trapping

Microfibres Containing Laminates Prepared by EPD: Microstructure and Fracture Behaviour

2015 ◽  
Vol 654 ◽  
pp. 53-57 ◽  
Author(s):  
Zdeněk Chlup ◽  
Hynek Hadraba ◽  
Daniel Drdlík ◽  
Ivo Dlouhý
Keyword(s):  
Mechanical Properties ◽  
Small Volume ◽  
Volume Fraction ◽  
Fracture Behaviour ◽  
Thin Layers ◽  
Internal Stresses ◽  
Alumina Matrix ◽  
Fracture Properties ◽  
Small Volume Fraction ◽  
Crack Trapping

Recently it was possible to prepare tailored laminates with perfect and strong interface of layers with precise thickness management. Tailoring of ceramic laminates to obtain optimal mechanical properties with enhanced fracture resistance is possible when predictions based on numerical calculations are employed. Extraordinary mechanical properties were achieved via high internal stresses development during material processing. The aim of this investigation can be seen in two directions. The enhanced crack free green bodies through incorporating small volume fraction of micro-fibres to the powders were prepared. Additionally, control of the crack propagation by incorporated directionally oriented micro-fibres both in the volume and in individual layers. In this contribution both alumina and zirconia micro-fibres were used to help eliminate drying defects in the green body stage before sintering. The co-deposition of ceramic micro-fibres and powder led to the preparation of microstructures having unique orthogonal fracture properties. Developed laminate with thin layers created by zirconia micro-fibres in the alumina matrix seems to be the most promising. This type of material exhibited potential of the crack trapping and deflection even when very small amount of micro-fibres was used.

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