Ductile grains, deformation

Mechanical compaction resulted in the rearrangement and fracturing of brittle grains, and deformation of ductile grains such as mica and mud intraclasts to form pseudomatrix. Intraclastic pseudomatrix is common in some medium- to... 

A series of events can take place in response to the thermal stresses (/) plastic deformation of the ductile metal matrix (sHp, twinning, cavitation, grain boundary sliding, and/or migration) (2) cracking and failure of the brittle fiber (5) an adverse reaction at the interface and (4) failure of the fiber—matrix interface (17—20). 

When GBS is accommodated by some of the mechanisms involving dislocation movement or diffusion of point defects, the grains retain almost the original size and shape even after large deformations. This GBS, as the primary mechanism for deformation, is the basis for the high ductility exhibited... 

Fig. 12. Schematic deformation properties of nanophase ceramics. For ceramics, decreasing the grain size into the nanometer regime corresponds to an increase in grain boundary sliding, resulting in increased ductility of these materials. (Adapted and redrawn from Siegel, 1994.)...

Single-crystal and poly crystalline transition metal carbides have been investigated with respect to creep, microhardness, plasticity, and shp systems. The fee carbides show slip upon mechanical load within the (111)plane in the 110 direction. The ductile-to-brittle transformation temperature of TiC is about 800 °C and is dependent on the grain size. The yield stress of TiC obeys a Hall Petch type relation, that is, the yield stress is inversely proportional to the square root of the grain size. TiC and ZrC show plastic deformation at surprisingly low temperatures around 1000 °C. 

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