Grain size dependent grain boundary defect structure: case of doped zirconia

A closed-form model was proposed to evaluate the elastic properties of nanocrystalline materials as a function of grain size. Grain-boundary sliding, present in nanocrystalline materials even at relatively low temperatures, was included in the formulation. The proposed analytical model agrees reasonably well with the experimental results for nanocrystalline copper and palladium.

Download Full-text

Hardening effects of grain boundary defect structure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010929x ◽

1978 ◽

Vol 36 (1) ◽

pp. 430-431

Author(s):

Eswarahalli S. Venkatesh ◽

L.E. Murr

Keyword(s):

Grain Boundary ◽

Defect Structure ◽

Structural Features ◽

Metals And Alloys ◽

Thermal Treatments ◽

Dislocation Source ◽

Boundary Defect ◽

Ledge Density ◽

Hot Rolled ◽

Boundary Ledge

The grain boundary defect structure can be changed to advantage by appropriate mechanical and thermal treatments. Researchers continue to show interest in understanding the effects of boundary defect structure on the mechanical properties of polycrystalline metals and alloys. Grain boundary structural features such as boundary ledges have been considered as a means of strengthening in metals and alloys. Considering the various models of Hall-Petch analyses, the grain boundary strength, σg can be expressed as σg = 8αGb(l-υ)m(L/ℓ); where m is the grain boundary ledge density, L is the grain size, ℓ is the distance of dislocation source in the adjacent grain matrix from the boundary, and G, b, and υ have the usual meaning. In particular, the influence of grain boundary ledge density on the strength (hardness) of grain boundaries is considered in the present paper.In the present investigation, pure (99.98%) nickel sheet mill (hot) rolled to 0.022 in. thick was used.

Download Full-text

Strain gradient plasticity analysis of the grain-size-dependent strength and ductility of polycrystals with evolving grain boundary confinement

Acta Materialia ◽

10.1016/j.actamat.2010.06.052 ◽

2010 ◽

Vol 58 (17) ◽

pp. 5768-5781 ◽

Cited By ~ 28

Author(s):

T.J. Massart ◽

T. Pardoen

Keyword(s):

Grain Size ◽

Grain Boundary ◽

Strain Gradient ◽

Strain Gradient Plasticity ◽

Gradient Plasticity ◽

Size Dependent ◽

Strength And Ductility

Download Full-text

Correlation of grain boundary defect structure with boundary orientation in Ba2YCu3O7−x

Applied Physics Letters ◽

10.1063/1.100502 ◽

1988 ◽

Vol 53 (21) ◽

pp. 2105-2107 ◽

Cited By ~ 21

Author(s):

S. Nakahara ◽

G. J. Fisanick ◽

M. F. Yan ◽

R. B. van Dover ◽

T. Boone

Keyword(s):

Grain Boundary ◽

Defect Structure ◽

Boundary Defect ◽

Boundary Orientation

Download Full-text

Grain Size Dependent Mechanical Properties in Nanophase Materials

MRS Proceedings ◽

10.1557/proc-362-219 ◽

1994 ◽

Vol 362 ◽

Cited By ~ 26

Author(s):

Richard W. Siegel ◽

Gretchen E. Fougere

Keyword(s):

Mechanical Properties ◽

Mechanical Property ◽

Grain Size ◽

Grain Boundary ◽

Present Knowledge ◽

New Materials ◽

Size Dependent ◽

Grain Structures ◽

Nanophase Materials ◽

Property Changes

AbstractIt has become possible in recent years to synthesize metals and ceramics under well controlled conditions with constituent grain structures on a nanometer size scale (below 100 nm). These new materials have mechanical properties that are strongly grain-size dependent and often significantly different than those of their coarser grained counterparts. Nanophase metals tend to become stronger and ceramics are more easily deformed as grain size is reduced. The observed mechanical property changes appear to be related primarily to grain size limitations and the large percentage of atoms in grain boundary environments. A brief overview of our present knowledge about the grain-size dependent mechanical properties of nanophase materials is presented.

Download Full-text