A point defect model for fatigue crack initiation in Ni3Al+B single crystals

The Interaction of Point Defects with Stress Fields Generated by Persistent Slip Bands in Face‐Centered Cubic Nickel

“…In addition, the role of the interface between PSBs and the matrix as a preferential site for the initiation of stage-I shear cracks has been noted in numerous studies. [2][3][4][5]9,14,36,37] Comparing Figure 5a,b, the influence of vacancies on the resulting stress fields is apparent.…”

“…The material frame difference is ensured by formulating the laws governing vacancy diffusion in the undeformed material configuration. Using the finite difference approach, Equation 15and (14), which govern the evolution of the fundamental field variables, are solved explicitly by the forward marching Euler scheme. The mechanical equilibrium Equation 12is solved with an explicit finite difference scheme with a staggered grid.…”

“…The evolution of the surface relief due to a combination of dislocation motion and the transport of point defects at surface-connected PSBs is documented. [2][3][4]14] However, a fundamental understanding of the evolution, the micromechanical fields around PSBs, and the microstructural mechanisms influencing the evolution of the structure of PSBs is unresolved. It has been suggested that point defects play a major role on the character of the PSBs; however, the relative contributions from point defects are still subject to conjecture.…”

Micro-mechanism of rolling contact fatigue in Hadfield steel crossing

“…In recent years, a large volume of research has confirmed that a lot of vacancies can be generated in metals by cyclic plastic deformation [17][18][19][20], and the quantity of the vacancies increases with increasing cyclic number in the early fatigue stage [20,21]. So it has been suggested that fatigue cracks are induced by vacancies [22,23].…”

Generation and accumulation of atomic vacancies due to dislocation movement and pair annihilation

“…Vacancy concentration in Fe deformed 20% at room temperature was reported to be at the order of 10 −5 [1], which is obviously far beyond the thermal equilibrium concentration. There have been a wide variety of studies on the effect of excess vacancies on diffusion [2,3], nucleation of precipitate [4], recrystallisation [5], movement of grain boundaries [6,7], creep deformation [8], generation of nano-voids [9][10][11], fatigue crack initiation in persistent slip bands [12][13][14][15] and strain localisation and plastic instability [16][17][18]. Interactions between hydrogen and vacancy [19,20], or hydrogen-vacancy complex and dislocations [21] are other points of current discussion.…”