Cleavage Fracture
Thus, cleavage fracture is characterized by low stress, low deformation, and low toughness. (2) Arising suddenly and catastrophically. Cleavage fracture develops at a very high speed (up to 1000-3000 m/s), which may cause a catastrophic accident in a very short time without perceptible omen.
A local approach to cleavage fracture modeling: An overview …
With cleavage fracture toughness conveniently described by a Weibull distribution (let us assume a two-parameter distribution for convenience), then a twofold mixed Weibull distribution describing cleavage fracture toughness, as characterized by J c, could be of the form (11) F X (J c) = p 1-exp J c β WM α WM + (1-p) 1-exp J c β BM α BM ...
Characteristics and mechanisms of hydrogen-induced quasi …
Ming and Wei [10] attributed their observation of {110}-type quasi-cleavage fracture in the presence of hydrogen to the fact that {110} is the dominant slip plane for martensite, i.e. slip structures, for example slip bands or dislocation cells, associated with the {110} plane can interact with hydrogen, causing glide plane decohesion or slip ...
Fracture surface microstructure and new fracture mechanism …
The cleavage fracture within a specific dimple propagates to adjacent dimples, causing cleavage fracture in adjacent regions. The scale of the cleavage fracture in this sample is different from the large-scale cleavage fracture shown in Fig. 2, which is simply because of the size of the pearlite colonies or blocks.
Failure of metals I: Brittle and ductile fracture
This is the first of three overviews on failure of metals. Here, brittle and ductile failure under monotonic loadings are addressed within the context of the local approach to fracture. In this approach, focus is on linking microstructure, physical mechanisms and overall fracture properties. The part on brittle fracture focuses on cleavage and ...
Bridging microstructure and crystallography with the …
In Charpy impact testing, due to the presence of large stress triaxiality near the notch-tip along with high applied strain rate (~1000 s − 1), the critical size of the nucleated crack before reaching the material K IC (plane-strain fracture toughness) can be of the order of few interlamellar spacings [24].
A forming limit framework accounting for various failure …
The critical strain loci of cleavage fracture under loading conditions of plane stress (σ 2 = 0, or σ 3 = 0) and generalized plane strain tension (θ ¯ = 0) are plotted as blue curves in the 2D figures, respectively. It should be noted that the cleavage fracture locus is only presented for the failure probability of 50% for visualization ...
Micromechanics of cleavage fracture and the associated …
The fracture surface (in Fig. 3 (a)) of the Charpy specimen broken at −120 °C in the lower shelf regime exhibits cleavage facets, which are characteristic of transgranular brittle failure. Within the facets there are typical features like river patterns and tongues [ 17, 27, 28 ], some of which are delineated by yellow and red dotted ...
A microdamage model for FCC single crystals considering a …
The two fracture modes usually coexist in nickel-based single crystal alloys, and the transition from cleavage fracture to ductile fracture attracts wide attention (Chen et al., 2020). Therefore, it is of great significance to study the damage mechanisms and establish a general damage model considering these two fracture modes for the failure ...
Elasto-viscoplastic phase field modelling of anisotropic …
A finite-strain anisotropic phase field method is developed to model the localisation of damage on a defined family of crystallographic planes, characteristic of cleavage fracture in metals. The approach is based on the introduction of an undamaged configuration, and the inelastic deformation gradient mapping this configuration to a damaged ...