Grain boundary contributions to deformation and solid-state flow in severe plastic deformation

2005 ◽  
Vol 409 (1-2) ◽  
pp. 13-23 ◽  
Author(s):  
E.V. Esquivel ◽  
L.E. Murr
2011 ◽  
Vol 683 ◽  
pp. 69-79 ◽  
Author(s):  
Evgeny V. Naydenkin ◽  
Galina P. Grabovetskaya ◽  
Konstantin Ivanov

In this review the investigations of deformation process development are discussed which were carried out by tension and creep in the temperature range Т<0.4Tm (here Тm is the absolute melting point of material) for nanostructured metals produced by the methods of severe plastic deformation. The contribution of grain boundary sliding to the total deformation in the above temperature interval is also considered. An analysis is made of the effect of grain size and grain boundary state on the evolution of grain boundary sliding and cooperative grain boundary sliding in nanostructured metals.


2012 ◽  
Vol 14 (11) ◽  
pp. 968-974 ◽  
Author(s):  
Xavier Sauvage ◽  
Artur Ganeev ◽  
Yulia Ivanisenko ◽  
Nariman Enikeev ◽  
Maxim Murashkin ◽  
...  

2011 ◽  
Vol 312-315 ◽  
pp. 1116-1125
Author(s):  
Vladimir V. Popov

Recent models of grain-boundary diffusion are briefly reviewed. Models of diffusion along equilibrium boundaries of recrystallization origin in coarse-grained materials and along non-equilibrium boundaries in nanocrystalline materials obtained by gas condensation and compacting or by severe plastic deformation are considered separately.


2015 ◽  
Vol 5 ◽  
pp. 111-126
Author(s):  
Evgeny V. Naydenkin ◽  
Galina P. Grabovetskaya ◽  
I.P. Mishin

Experimental studies on the grain boundary diffusion and processes controlled by it in the ultrafine-grained metallic materials produced by various methods of severe plastic deformation are reviewed. Correlation between the increased diffusion permeability of grain boundaries and features of recrystallization and deformation development in these materials possessing the non-equilibrium state of grain boundaries formed during severe plastic deformation in the temperature range of T < 0.35Tm is demonstrated and analyzed.


2016 ◽  
Vol 367 ◽  
pp. 130-139 ◽  
Author(s):  
Vladimir V. Popov ◽  
A.V. Sergeev

The grain-boundary diffusion of Co in ultra-fine grained Mo processed by high-pressure torsion has been studied by emission Mössbauer spectroscopy and radio-tracer analysis. It is demonstrated that under the severe plastic deformation by high-pressure torsion the non-equilibrium grain boundaries are formed which are the ultra-fast diffusion paths. At annealing in the temperature range of 623-823 K the relaxation of the non-equilibrium boundaries proceeds and their properties approach to those of equilibrium boundaries of recrystallization origin.


2015 ◽  
Vol 5 ◽  
pp. 43-54 ◽  
Author(s):  
Ruslan Z. Valiev

Nanostructuring of metals and alloys by severe plastic deformation techniques is an effective way of enhancing their mechanical and functional properties. The features of the nanostructured materials produced by severe plastic deformation (SPD) are stipulated by forming of ultrafine-sized grains as well as by the state of grain boundaries. The concept of grain boundary (GB) design of ultrafine-grained metals and alloys is developed for enhancement of their properties by tailoring grain boundaries of different types (low-angle and high-angle ones, special and random, equilibrium and nonequilibrium) and formation of grain boundary segregations and precipitations by SPD processing. The paper presents experimental data demonstrating the super-strength and “positive” slope of the Hall-Petch relation when passing from micro-to nanostructured state in a number of metallic materials subjected to severe plastic deformation. The nature of the superior strength is associated with new strengthening mechanisms and the difficulty of generation of dislocations from grain boundaries with segregations. This new approach is used for achieving the enhanced strength in several commercial Al and Ti alloys as well as steels subjected to SPD processing.


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