TY - CHAP

T1 - Microstructure and creep properties of MEZ magnesium alloy processed by thixocasting

AU - Morales Garza, Emma D.

AU - Dieringa, Hajo

AU - Hort, Norbert

AU - Kainer, Karl U.

N1 - Conference code: 141

PY - 2012

Y1 - 2012

N2 - Whereas in most magnesium applications die casting is the dominant manufacturing process, thixocasting recently came into focus of producers. This is mainly due to the improved microstructure, reduced porosity and better mechanical properties. An important issue for the introduction and use of magnesium alloys in automotive industry is their creep resistance. Aluminum free magnesium alloys are known to show improved creep strength compared to conventional aluminum containing alloys due to the absence of beta phase (Mg 17Al 12). MEZ alloy (Mg-RE-Zn-Zr) shows better creep resistance even compared to AE42 in die casting. In this paper, the mechanical and creep properties from thixocast MEZ alloy are evaluated from creep tensile tests at temperatures of 135°C, 150°C and 175°C and at stresses between 60 and 100 MPa. The creep activation energy and the stress exponent are calculated and discussed. Optical, scanning and transmission electron microscopy of the microstructural features developed after the mechanical tests helps to understand the deformation mechanisms occurring during creep and to explain the creep properties after thixocasting.

AB - Whereas in most magnesium applications die casting is the dominant manufacturing process, thixocasting recently came into focus of producers. This is mainly due to the improved microstructure, reduced porosity and better mechanical properties. An important issue for the introduction and use of magnesium alloys in automotive industry is their creep resistance. Aluminum free magnesium alloys are known to show improved creep strength compared to conventional aluminum containing alloys due to the absence of beta phase (Mg 17Al 12). MEZ alloy (Mg-RE-Zn-Zr) shows better creep resistance even compared to AE42 in die casting. In this paper, the mechanical and creep properties from thixocast MEZ alloy are evaluated from creep tensile tests at temperatures of 135°C, 150°C and 175°C and at stresses between 60 and 100 MPa. The creep activation energy and the stress exponent are calculated and discussed. Optical, scanning and transmission electron microscopy of the microstructural features developed after the mechanical tests helps to understand the deformation mechanisms occurring during creep and to explain the creep properties after thixocasting.

KW - Creep

KW - MEZ magnesium alloy

KW - Microstructure

KW - Semi-solid processing

KW - Thixocasting

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84860802813&partnerID=8YFLogxK

M3 - Article in conference proceedings

AN - SCOPUS:84860802813

SN - 9781118291214

SN - 978-3-319-48202-6

T3 - Magnesium Technology

SP - 385

EP - 389

BT - Magnesium Technology 2012 - Held During TMS 2012 Annual Meeting and Exhibition

A2 - Mathaudhu, Suveen N.

A2 - Sillekens, Wim H.

A2 - Neelameggham, Neale R.

A2 - Hort, Nobert

PB - Springer Schweiz

CY - Cham

T2 - 141st Annual Meeting and Exhibition of the Magnesium Technology - TMS 2012

Y2 - 11 March 2012 through 15 March 2012

ER -