Deformation of Transformation Toughened Zirconia

1986 ◽  
Vol 78 ◽  
Author(s):  
James Lankford
Keyword(s):  
Plastic Deformation ◽  
Flow Behavior ◽  
Deformation Mode ◽  
Grain Boundary Sliding ◽  
Shear Stresses ◽  
State Of Stress ◽  
Boundary Sliding ◽  
Recent Experimental Work ◽  
Temperature Strain

ABSTRACTRecent experimental work on the yield and flow behavior of both single crystal and polycrystalline transformation toughened zirconia is presented. In addition, related work by other researchers is reviewed. The resulting picture is used to assess the relative plastic deformation contributions of phase transformations, dislocation activity, and grain boundary sliding. Particular emphasis is placed on the effects of stabilizer chemistry, grain size, temperature, strain rate, and state of stress. The results are shown to reflect the strong role of shear stresses in selecting, and controlling the operation of, each deformation mode.

Two-Dimensional Molecular Dynamics Simulation for Studying of Grain Refinement

2016 ◽  
Vol 838-839 ◽  
pp. 361-366 ◽  
Author(s):  
Julia A. Baimova ◽  
Sergey V. Dmitriev
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Molecular Dynamics Simulation ◽  
Grain Refinement ◽  
Simulation Method ◽  
Grain Boundary Sliding ◽  
Dynamics Simulation ◽  
Shear Stresses ◽  
Two Dimensional ◽  
Boundary Sliding

The molecular dynamics simulation method in two-dimensional case is presented for the simulation of grain refinement and can be applied to the investigation of grain boundary sliding and defects movement under severe plastic deformation. Nanopolycrystalline system is shown as the example of the application of the method proposed. Atomistic details of structure formation and grain growth (refinement) are shown by the example of change of loading scheme. It was shown that elongated grains which appear under plastic deformation can grow up even larger or be destroyed, depending on the direction of the applied maximal shear stresses.

Monotonic and Cyclic Behavior of Ultrafine Grain Metals:Overview

2006 ◽  
Vol 503-504 ◽  
pp. 267-274 ◽  
Author(s):  
Alexei Vinogradov
Keyword(s):  
Plastic Deformation ◽  
Cyclic Stress ◽  
Grain Boundary Sliding ◽  
Cyclic Behavior ◽  
Ultrafine Grain ◽  
Strain Behavior ◽  
Fine Grain ◽  
Boundary Sliding ◽  
The Common

The available to date experimental results are reviewed with regard to the common aspects and features of monotonic and cyclic stress-strain behavior of various ultra-fine grain materials produced by severe plastic deformation (SPD). Some possible mechanisms of plastic flow and degradation during monotonic and cyclic testing are discussed from the standpoint of initial SPD structure and its evolution upon loading. The role of two strengthening mechanisms – dislocation accumulation and grain reduction - is highlighted. The key importance of grain boundaries for the mechanical behavior, strain localization and fracture of ultra-fine grain metals is argued and the experimental evidence is presented on the significance of grain boundary sliding in their plastic deformation. The results of phenomenological modeling of the monotonic and cyclic response of ultra-fine grain metals are presented in terms of dislocation kinetics and a satisfactory agreement with experimental data is demonstrated.

The Effect of Grain Boundary State on Deformation Process Development in Nanostructured Metals Produced by the Methods of Severe Plastic Deformation

2011 ◽  
Vol 683 ◽  
pp. 69-79 ◽  
Author(s):  
Evgeny V. Naydenkin ◽  
Galina P. Grabovetskaya ◽  
Konstantin Ivanov
Keyword(s):  
Plastic Deformation ◽  
Grain Boundary ◽  
Severe Plastic Deformation ◽  
Deformation Process ◽  
Process Development ◽  
Grain Boundary Sliding ◽  
Total Deformation ◽  
Nanostructured Metals ◽  
Boundary State ◽  
Boundary Sliding

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.

Role of Grain Boundary Sliding in Texture Evolution for Nanoplasticity

2017 ◽  
Vol 20 (4) ◽  
pp. 1700212 ◽  
Author(s):  
Yajun Zhao ◽  
Laszlo S. Toth ◽  
Roxane Massion ◽  
Werner Skrotzki
Keyword(s):  
Grain Boundary ◽  
Texture Evolution ◽  
Grain Boundary Sliding ◽  
Boundary Sliding

Superplasticity of Aerospace 7075 (Al-Zn-Mg-Cu) Aluminium Alloy Obtained by Severe Plastic Deformation

2018 ◽  
Vol 385 ◽  
pp. 39-44 ◽  
Author(s):  
Fernando Carreño ◽  
Oscar A. Ruano
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Aluminium Alloy ◽  
Room Temperature ◽  
Grain Boundary Sliding ◽  
Strain Rates ◽  
Aerospace Applications ◽  
Boundary Sliding ◽  
Processing Stress

The 7075 (Al-Zn-Mg-Cu) aluminium alloy is the reference alloy for aerospace applications due to its specific mechanical properties at room temperature, showing excellent tensile strength and sufficient ductility. Formability at high temperature can be improved by obtaining superplasticity as a result of fine, equiaxed and highly misoriented grains prone to deform by grain boundary sliding (GBS). Different severe plastic deformation (SPD) processing routes such as ECAP, ARB, HPT and FSP have been considered and their effect on mechanical properties, especially at intermediate to high temperatures, are studied. Refined grains as fine as 100 nm and average misorientations as high as 39o allow attainment of high strain rate superplasticity (HSRSP) at lower than usual temperatures (250-300oC). It is shown that increasing misorientations are obtained with increasing applied strain, and increasing grain refinement is obtained with increasing processing stress. Thus, increasing superplastic strains at higher strain rates, lower stresses and lower temperatures are obtained with increasing processing strain and, specially, processing stress.

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