ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Cyclic extrusion compression (CEC) is an effective severe plastic deformation (SPD)process which can be used for fabricating ultrafine grained light materials such as magnesium alloys.This method introduces three-dimensional compression and shear stresses and the process can berepeated for a certain number of passes until the desired accumulated strain has been introduced. Inorder to reveal the effect of second phases on the microstructure developed in magnesium alloysduring CEC, three different alloys (AZ31, AZ31-1wt.%Si and AZ91) were investigated after CEC 7passes performed at 225°C. The experimental results show that the CEC process can effectivelyrefine the microstructures of these alloys and the mean grain size achieved is 1.3µm, 1.5µm and1.4µm, respectively. It is revealed that the grain size, grain shape and grain boundary structures arelittle affected by coarse phase Mg2Si but strongly affected by the fine phase Mg17Al12. The finephase Mg17Al12 seems to increase the relative grain misorientations, hence enhancing the formationof high angle grain boundaries (HAGBs). It is expected that such changes are improvingmechanical properties, subsequent forming behavior and surface quality
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.584-586.523.pdf
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