Paper Title:
Microstructural Evolution and Creep of an Al-0.2wt.%Sc Alloy after Equal-Channel Angular Pressing
  Abstract

Experiments were conducted on an Al-0.2wt.%Sc alloy to evaluate the effect of equalchannel angular pressing (ECAP) on its creep behaviour. ECAP was conducted at room temperature with a die that had an internal angle of 90° between the two parts of the channel. The subsequent extrusion passes were performed by route BC up to 8 ECAP passes. Creep tests in tension were performed on the as-pressed samples at 473 K under an applied stress range between 10 to 50 MPa. For comparison purposes, some creep tests were performed also on the unpressed alloy. Following ECAP and creep testing, samples were prepared for examination by means of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) equipped with an electron back scattering diffraction (EBSD) unit. The observation of the surface of the ECAPed samples after creep exposure showed the occurrence of mesoscopic shear bands. The EBSD data reveal that these bands are separated by high angle grain boundaries. The creep resistance of an alloy is a little decreased after one ECAP pass. However, successive ECAP pressing lead to a noticeable decrease of the creep properties. Thus, the Al-0.2wt.%Sc alloy processed by 8 ECAP passes exhibited faster creep rate by about two and/or three orders of magnitude than the unpressed alloy when creep testing at 473 K and at the same applied stress. The detrimental effect of ECAP on the creep resistance is probably a consequence of a synergetic effect of mesoscopic sliding of groups of grains along shear bands, more intensive grain boundary sliding and creep cavitation in creep of the ultrafine-grained material.

  Info
Periodical
Materials Science Forum (Volumes 584-586)
Edited by
Yuri Estrin and Hans Jürgen Maier
Pages
846-851
DOI
10.4028/www.scientific.net/MSF.584-586.846
Citation
P. Král, J. Dvořák, V. Sklenička, "Microstructural Evolution and Creep of an Al-0.2wt.%Sc Alloy after Equal-Channel Angular Pressing ", Materials Science Forum, Vols. 584-586, pp. 846-851, 2008
Online since
June 2008
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Jeong Min Kim, Bong Koo Park, Joong Hwan Jun, Ki Tae Kim, Woon Jae Jung
Abstract:Small amounts of minor alloying elements such as RE and Sr were added to Mg- 8wt%Al-5wt%Zn (AZ91D+4%Zn), and their effects on the...
374
Authors: Zhi Min Zhang, Qiang Wang, B.C. Li, X. Zhang
Abstract:Warm compression tests of AZ31 Mg alloy were carried out at five temperatures in 30°C intervals from 210°C to 330°C. The samples of...
1813
Authors: Bao Hong Zhu, Bai Qing Xiong, Yon Gan Zhang, Udo Fritsching, Ji Shan Zhang, Feng Wang, Zhi Hui Li, Hong Wei Liu
Abstract:A high Zn content Al-Zn-Mg-Cu alloy was prepared by spray forming process and the precipitate behavior and microstructure of the extruded...
481
Authors: N.I. Vlasova, V.S. Gaviko, A.G. Popov, N.N. Shchegoleva, L.A. Stashkova, Dmitriy Gunderov, Xavier Sauvage
Abstract:Equiatomic FePd alloy in the ordered state has been processed by means of high-pressure torsion deformation (HPTD) and then annealed. X-ray...
392
Authors: De Liang Zhang, Hong Bao Yu, Yuong Chen
Abstract:Bulk nanostructured (grain sizes in the range of 50-200nm) and ultrafine structured (grain sizes in the range of 100-500nm) -TiAl based...
149