TY - CHAP

T1 - Influence of processing route on the properties of magnesium alloys

AU - Frank, Hagen

AU - Hort, Norbert

AU - Dieringa, Hajo

AU - Kainer, Karl Ulrich

N1 - Conference code: 10

PY - 2008

Y1 - 2008

N2 - Magnesium alloys had gained an increasing interest in recent years due to their promising property profile for light weight constructions. They offer drastic advantages in weight reductions in automotive industries compared to steel or even aluminium. Therefore they can be used to decrease the emission of green house gases as requested by the EU directive for the reduction of CO 2 emissions and moreover due to their recyclability they also help to fulfill the requirements from the EU directive regarding the end of life of vehicles. But still there are some limitations with regard to strength, mostly at elevated temperatures above 130°C. To overcome these limitations alloy development as well as process optimization has to be done for further enhancement of the range of magnesium applications. This paper will show and discuss the property profiles of the standard magnesium alloy AZ91D compared to the recently developed, heat resistant magnesium alloy MRI153. The alloys have been processed using normal high pressure die casting (HPDC), New Rheocasting (NRC) and Thixomolding® (TM). As methods of investigation tensile and creep tests have been applied. The creep properties have been determined in the temperature range of 135-150°C and loads of 50-85 MPa. All these trials have been accompanied by metallographic observations (light optical metallography, SEM) and density measurements to investigate the influence of the processing routes on microstructure and the porosity of the materials. It will be shown that the differences in the property profile of the chosen alloys are dependent on their different chemical compositions as well as on different microstructures that are obtained by the different processing routes. While in the case of AZ91D, TM is showing advantages compared to HPDC for room temperature applications, the NRC in combination with the heat resistant alloy leads to an improvement of creep rates by two orders of magnitudes.

AB - Magnesium alloys had gained an increasing interest in recent years due to their promising property profile for light weight constructions. They offer drastic advantages in weight reductions in automotive industries compared to steel or even aluminium. Therefore they can be used to decrease the emission of green house gases as requested by the EU directive for the reduction of CO 2 emissions and moreover due to their recyclability they also help to fulfill the requirements from the EU directive regarding the end of life of vehicles. But still there are some limitations with regard to strength, mostly at elevated temperatures above 130°C. To overcome these limitations alloy development as well as process optimization has to be done for further enhancement of the range of magnesium applications. This paper will show and discuss the property profiles of the standard magnesium alloy AZ91D compared to the recently developed, heat resistant magnesium alloy MRI153. The alloys have been processed using normal high pressure die casting (HPDC), New Rheocasting (NRC) and Thixomolding® (TM). As methods of investigation tensile and creep tests have been applied. The creep properties have been determined in the temperature range of 135-150°C and loads of 50-85 MPa. All these trials have been accompanied by metallographic observations (light optical metallography, SEM) and density measurements to investigate the influence of the processing routes on microstructure and the porosity of the materials. It will be shown that the differences in the property profile of the chosen alloys are dependent on their different chemical compositions as well as on different microstructures that are obtained by the different processing routes. While in the case of AZ91D, TM is showing advantages compared to HPDC for room temperature applications, the NRC in combination with the heat resistant alloy leads to an improvement of creep rates by two orders of magnitudes.

KW - Creep behavior

KW - High pressure die casting

KW - Magnesium alloys

KW - Microstructure

KW - New rheocasting

KW - Porosity

KW - Tensile properties

KW - Thixomolding®

UR - http://www.scopus.com/inward/record.url?scp=58049216754&partnerID=8YFLogxK

M3 - Article in conference proceedings

AN - SCOPUS:58049216754

SN - 9771012039401

T3 - Solid State Phenomena

SP - 43

EP - 48

BT - Semi-Solid Processing of Alloys and Composites X - Selected

PB - Trans Tech Publications Ltd

T2 - 10th International Conference on Semi-Solid Processing of Alloy and Composites - S2P 2008

Y2 - 16 September 2008 through 18 September 2008

ER -