8Ebrahimi R,Reihanianb M, Kanaani M,et al. An upper-bound analysis of the tube extrusion process [ J ]. Journal of Materials Processing Technology,2008,199 : 214-220.
9Winany C D. Magnesium Die-Castings in Motor Vehicles An Smith D S. Magnesium the Lightweight Solution-Automotive Sou ring Special Report[ R]. London: Automotive Sourcing UK Ltd 1998:8-9.
10Ruminski, Luksza J, Kusizk J. Analysis of the die shape on the distribution of mechanical properties and strain field in the tube sinking process[J]. J M at Proc Tech, 1998, (80-81) : 683- 689.