Three-dimensional numerical analysis and experimental investigation of grain refinement in multi-pass equal channel angular pressing for round-workpieces

2007 ◽  
Vol 1 (2) ◽  
pp. 187-196
Author(s):  
Shubo Xu ◽  
Guoqun Zhao ◽  
Xin Wu ◽  
Xinwu Ma ◽  
Yanjin Guan
Keyword(s):  
Experimental Investigation ◽  
Numerical Analysis ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
Three Dimensional ◽  
Angular Pressing

scholarly journals Increase in Total Elongation Caused by Pure Shear Deformation in Ultra-Fine-Grained Cu Processed by Equal-Channel Angular Pressing

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 654
Author(s):  
Ryosuke Matsutani ◽  
Nobuo Nakada ◽  
Susumu Onaka
Keyword(s):  
Shear Deformation ◽  
Equal Channel Angular Pressing ◽  
Pure Shear ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Total Elongation ◽  
Local Deformation ◽  
Image Correlation ◽  
Fine Grained ◽  
Angular Pressing

Ultra-fine-grained (UFG) Cu shows little total elongation in tensile tests because simple shear deformation is concentrated in narrow regions during the initial stage of plastic deformation. Here, we attempted to improve the total elongation of UFG Cu obtained by equal-channel angular pressing. By making shallow dents on the side surfaces of the plate-like specimens, this induced pure shear deformation and increased their total elongation. During the tensile tests, we observed the overall and local deformation of the dented and undented UFG Cu specimens. Using three-dimensional digital image correlation, we found that the dented specimens showed suppression of thickness reduction and delay in fracture by enhancement of pure shear deformation. However, the dented and undented specimens had the same ultimate tensile strength. These results provide us a new concept to increase total elongation of UFG materials.

An Investigation of Cavitation and Suction Vortices Behavior in Pump Sump

2011 ◽  
Author(s):  
Won-Tae Kang ◽  
Ki Han Yu ◽  
Seung Yeob Lee ◽  
Byeong Rog Shin
Keyword(s):  
Experimental Investigation ◽  
Numerical Analysis ◽  
Test Procedure ◽  
Three Dimensional ◽  
Water Levels ◽  
National Standard ◽  
Piping System ◽  
Test Model ◽  
Grid Systems ◽  
Volume Method

A numerical and an experimental investigation on a suction vortices including cavitation, free vortices and subsurface vortices behavior in the model sump system with multi-intakes is performed at several flow rates and water levels. A test model sump and piping system were designed based on Froude similitude for the prototype of the recommended structure layout by HI-9.8 American National Standard for Pump Intake Design of the Hydraulic Institute. An experiment is performed according to the sump model test procedure of Hyosung Goodsprings, Inc. A numerical analysis of three dimensional multiphase flows through the model sump is performed by using the finite volume method of the CFX code with multi-block structured grid systems. A k-ω Shear Stress Transport turbulence model and the Rayleigh-Plesset cavitation model are used for solving turbulence cavitating flow. Several types of free surface and submerged vortex which occurs with each different water level are identified through the experimental investigation. From the numerical analysis, the vortices are reproduced and their formation, growing, shedding and detailed vortex structures are investigated. To reduce abnormal vortices, an anti-vortex device is considered and its effect is investigated and discussed.

Influence of Stacking Fault Energy on the Microstructures and Grain Refinement in the Cu-Al Alloys during Equal-Channel Angular Pressing

2010 ◽  
Vol 667-669 ◽  
pp. 379-384 ◽  
Author(s):  
X.H. An ◽  
Shi Ding Wu ◽  
Z.F. Zhang
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
Al Alloys ◽  
Stacking Fault ◽  
High Recovery ◽  
Angular Pressing ◽  
High Recovery Rate ◽  
Refinement Mechanism ◽  
Stacking Fault Energies

The microstructural evolution and grain refinement of Cu-Al alloys with different stacking fault energies (SFEs) processed by equal-channel angular pressing (ECAP) were investigated. The grain refinement mechanism was gradually transformed from dislocation subdivision to twin fragmentation with tailoring the SFE of Cu-Al alloys. Concurrent with the transition of grain refinement mechanism, the grain size can be refined into from ultrafine region (1 m~100 nm) to the nanoscale (<100 nm) and then it is found that the minimum equilibrium grain size decreases in a roughly linear way with lowering the SFE. Moreover, in combination with the previous results, it is proposed that the formation of a uniform ultrafine microstructure can be formed more readily in the materials with high SFE due to their high recovery rate of dislocations and in the materials with low SFE due to the easy formation of a homogeneously-twinned microstructure.

scholarly journals Simulation and Experimental Investigation for the Homogeneity of Ti49.2Ni50.8 Alloy Processed by Equal Channel Angular Pressing

Metals ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 45 ◽  
Author(s):  
Diantao Zhang ◽  
Mohamed Osman ◽  
Li Li ◽  
Yufeng Zheng ◽  
Yunxiang Tong
Keyword(s):  
Experimental Investigation ◽  
Equal Channel Angular Pressing ◽  
Angular Pressing

Significance of Microdefects Induced by ECAP in Aluminium, Al-0.2%Sc Alloy and Copper

2007 ◽  
Vol 567-568 ◽  
pp. 93-96 ◽  
Author(s):  
Vladimir I. Betekhtin ◽  
Andrey G. Kadomtsev ◽  
Petr Král ◽  
Jiří Dvořák ◽  
Milan Svoboda ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Equal Channel Angular Pressing ◽  
Pure Aluminium ◽  
Creep Properties ◽  
Angular Pressing

This paper deals with an experimental investigation of the effect of various microdefects induced by equal-channel angular pressing (ECAP) on mechanical and creep properties of ultrafinegrained pure aluminium, an Al-0.2%Sc alloy and copper.

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