Cleavage cracking resistance of large-angle grain boundaries in Fe-3 wt% Si alloy

2002 ◽  
Vol 82 (17-18) ◽  
pp. 3333-3347 ◽  
Author(s):  
A. S. Argon ◽  
Y. Qiao
Keyword(s):  
Grain Boundaries ◽  
Large Angle ◽  
Cracking Resistance ◽  
Cleavage Cracking

On the problem of large angle grain boundaries

1959 ◽  
Vol 9 (6) ◽  
pp. 754-755
Author(s):  
E. F. Holländer
Keyword(s):  
Grain Boundaries ◽  
Large Angle

TEM and HREM Investigation of The Precipitation of Cobalt and Nickel In Polycrystalline Silicon

1991 ◽  
Vol 238 ◽  
Author(s):  
H. J. Möller ◽  
Juyong Chung ◽  
Lan Huang
Keyword(s):  
Grain Boundaries ◽  
Lattice Mismatch ◽  
Large Angle ◽  
Three Dimensional ◽  
Cobalt Disilicide ◽  
Surface Source ◽  
High Resolution Tem ◽  
Nickel Disilicide ◽  
Micrometer Size ◽  
Cobalt And Nickel

ABSTRACTThe precipitation behavior of cobalt and nickel at grain boundaries in multicrystalline silicon is investigated. The metals are diffused into the specimens from a surface source between 800 -1000 °C and the precipitation after cooling is studied by conventional and high resolution TEM. Cobalt and nickel disilicide precipitates nucleate both in the bulk and at grain boundaries. They form few large (micrometer size) plate-like or three-dimensional precipitates depending on the cooling rate. Cobalt disilicide with a slightly larger lattice mismatch has a higher tendency to nucleate at large angle grain boundaries. Both suicides nucleate preferentially at coherent twin boundaries forming a few atomic layers thick platelet parallel to the {111} twin plane. HREM and image simulations are performed to analyze the Si / MS12 / twin interface structure (M = Co, Ni).

Correlation between ZnSe Crystal Growth Conditions from Melt and Generation of Large-Angle Grain Boundaries and Twins

1994 ◽  
Vol 33 (Part 1, No. 4A) ◽  
pp. 1991-1994 ◽  
Author(s):  
Peter Rudolph ◽  
Kazuyuki Umetsu ◽  
Han Jun Koh ◽  
Tsuguo Fukuda
Keyword(s):  
Crystal Growth ◽  
Grain Boundaries ◽  
Large Angle ◽  
Growth Conditions ◽  
Znse Crystal

A dynamical model of a crystal structure - IV. Grain boundaries

1952 ◽  
Vol 212 (1111) ◽  
pp. 576-584 ◽  
Keyword(s):  
Crystal Structure ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Large Angle ◽  
Gradual Transition ◽  
Small Angle Boundary ◽  
Pure Metals ◽  
And Diffusion ◽  
Large Angle Boundary ◽  
Dislocation Walls

Four photographs of bubble rafts are used as a basis for discussion of the structure of grain boundaries in pure metals. In these photographs one can follow the gradual transition from a small-angle boundary made up of clearly separate dislocations to a large-angle boundary where the dislocation structure is hardly recognizable. As the angle is increased, a continuous shortening of the dislocations, accompanied by the widening of a crack on the tensile side, is seen, and the process culminates in a structure which is perhaps best described in terms of local fit and misfit. The fact is also illustrated that the dislocation content of the boundary depends on the angle of the boundary, as well as on the disorientation of the crystals that it separates. If a boundary turns it must therefore gain or lose dislocations. The bearing of this on the measurement of grain-boundary energies is discussed. Other points considered concern the range of validity of calculations of the energy of dislocation walls, and slip and diffusion along grain boundaries.

What types of grain boundaries can be passed through by persistent slip bands?

2003 ◽  
Vol 18 (5) ◽  
pp. 1031-1034 ◽  
Author(s):  
Z. F. Zhang ◽  
Z. G. Wang ◽  
J. Eckert
Keyword(s):  
Grain Boundaries ◽  
Large Angle ◽  
Fatigue Cracking ◽  
Stress Axis ◽  
Slip Systems ◽  
Slip Bands ◽  
Persistent Slip Bands ◽  
Different Types ◽  
The Difference ◽  
Intergranular Fatigue Cracking

Three typical interactions of persistent slip bands (PSBs) with different types of grain boundaries (GBs) were investigated and analyzed in fatigued copper crystals. The results show that PSBs cannot transfer through all types of large-angle GBs, regardless of their orientation with respect to the stress axis. Secondary slip was often observed near the GBs, leading to strain incompatibility. When the slip systems of the two adjacent crystals are coplanar, the transmission of a PSB across a GB strongly depends on the slip directions of the two adjacent crystals. It was found that only the low-angle GBs can be passed through by PSBs, and accordingly they are insensitive to intergranular fatigue cracking. For a special copper bicrystal with coplanar slip systems, the ladderlike dislocation arrangements within the adjacent PSBs become discontinuous and a dislocation-affected-zone appears near the GB due to the difference in the slip direction of the two adjacent crystals. Therefore, the necessary conditions for the transmission of a PSB across a GB are that the neighboring grains have a coplanar slip system and identical slip directions.

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