Nanopore Evolution Kinetics during Annealing of Submicrocrystalline Materials

2018 ◽  
Vol 63 (10) ◽  
pp. 1492-1496 ◽  
Author(s):  
V. N. Perevezentsev ◽  
A. S. Pupynin ◽  
A. E. Ogorodnikov
2011 ◽  
Vol 674 ◽  
pp. 97-103 ◽  
Author(s):  
Henryk Dybiec ◽  
Maciej Motyka

Light weight nano/submicrocrystalline materials are promising group of constructional materials combining low density with high mechanical properties. However, their potential application requires extensive testing of functional properties, e.g. tribological ones, which may be significant and determine their practical use. Available information on abrasive wear and friction coefficients in nano/submicrocrystalline materials is rather poor. Therefore the aim of this paper is to fill the gap in the literature in this field. The AlSi12Fe5Cu3Mg alloy (RS422) produced by rapid solidification and plastic consolidation with grain size of basic phase components in the range from 50 nm to 300 nm was examined. Microstructure and mechanical properties of the materials were determined. Abrasive wear tests, static and kinematics friction coefficients measurement were carried out under the surface condition including dry, wet and oil lubricant. The results have been compared to the values of similar quantities determined in the same conditions for conventionally produced alloy AlSi11FeCuMn (AK11). Substantial increase of friction coefficients for RS442 comparing to AlSi11FeCuMn material was found, however, abrasive wear for nano/submicron grained materials were low in comparison to conventional one. Considerable increase of abrasive wear at water presence and very weak attrition at oil lubrication was observed. Relationship between structure and mechanical properties of tested materials was analyzed.


Author(s):  
В.Н. Перевезенцев ◽  
А.C. Пупынин

A model decribed the nucleation of grain boundary nanopores in submicrocrystalline materials in the process of intensive plastic deformation is proposed. The effect of internal stress fields from planar mesodefects, external hydrostatic pressure and level of supersaturation of the material by nonequilibrium deformation-induced vacancies on the nucleation rate of nanopores is analyzed.


2004 ◽  
Vol 443-444 ◽  
pp. 111-114
Author(s):  
Radomír Kužel ◽  
D. Šimek ◽  
J. Kub ◽  
Rinat K. Islamgaliev

Two methods were used for the analysis of submicro-crystalline copper prepared by high-pressure (6 GPa) severe plastic deformation. Conventional powder XRD study was carried in terms of the modified Williamson-Hall (WH) plots and shown large line-broadening anisotropy. A new high-resolution small-angle transmission diffuse scattering method was applied for determination of crystallite size. Two methods were used for the evaluation of the diffuse scattering - calculation of the autocorrelation function of the crystalline shape by the transformation of the measured signal and by the direct fitting. Bimodal block size distribution has to be assumed for annealed samples. This was also confirmed by classical back-reflection film method as well as by the long tails of conventional diffraction profiles.


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