Warm forming of magnesium tubes is a promising method for forming complex-structural lightweight automotive parts. The method is limited by material formability on one hand but also by the quality of the extrusion seam when tubes are produced by porthole-die extrusion. To produce low cost tubes, bridge-die extrusion can be an attractive method provided an acceptable seam quality for forming applications could be produced. This paper presents the results of a forming study carried out on AM30 and AZ31 tubes produced by bridge-die extrusion. The tubes were formed using hot gas to determine the forming limit in plane-strain conditions and to study the fracture mode. It was shown that formability was limited due to the propensity for the tube to fail at the seam. A detailed analysis of the microstructure of the tubes along the transverse and longitudinal welds has revealed the importance of the microstructure at the weld seam interfaces when old billet material and new billet material co-exists along the tube. Failure at the seam was attributed to the presence of microstructure inhomogeneities at the seam.
Hot gas forming of magnesium tubes produced by bridge-die extrusion
MS&T, Materials Science and Technology, 2009 ; 2333-2344
2009
12 Seiten, 9 Quellen
Aufsatz (Konferenz)
Englisch
Automobilbau , Bruchmodul , Extrudieren (Metall) , Formbarkeit , Grenzwert , Halbwarmumformen , Heißgasstrahl , Inhomogenität , Knüppel (Halbzeug) , komplizierte Form , Kosteneinsparung , Kristallisation , Längsnaht , Leichtbauweise , Matrize (Umformwerkzeug) , MgAlZn-Legierung , Mikrostruktur , niedrige Kosten , Rohrextrusion , Rohrpressanlage (Metall) , Schweißnaht
Direct extrusion of magnesium alloy:a quick study method
Kraftfahrwesen | 1995
|Production of magnesium alloy tubes for superlight bicycles
Tema Archiv | 2000
|Engineering Index Backfile | 1954
|SAE Technical Papers | 1954
|Direct Extrusion of Magnesium Alloy: A Quick Study Method
SAE Technical Papers | 1995
|