The study on the Flow behavior of Magnesium alloy AZ91D in die casting of a thin-walled plane component

• Main Authors: Shun-Ta Yu, 余順達
• Other Authors: Ray-Quen Hsu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/04034660341173892911

碩士 === 國立交通大學 === 機械工程系 === 91 === ABSTRACT Magnesium alloys are metals which have high specific strength, low density and high thermal conductivity. They are non-magnetic materials with very good damping and EMI shielding capacities. These characteristics enable the magnesium alloys to be used in the communication, electronic devices and many other computer components. Among these applications, the chassis of notebook computer becomes one of the prominent usages in recent years. The chassis are usually thin-walled plate constructions, manufactured by die casting or semi-solid forming process which encounters many difficulties. In order to increase the yield of magnesium alloy in die casting, this study simulate the thin-walled plate in die casting process with a commercial code FLOW-3D, investigates the material flow in the die cavity, its solidification in the mold and their relations to defects of the products. The gate system effects on the results of the die casting products are also discussed. From the simulation, it is found that for AZ91D magnesium alloy, the best die casting parameter combination is: casting pressure 100 MPa, liquid flow speed 110 m/s, casting temperature 630℃ and mold temperature 240℃. This die casting condition promotes lower temperature variation in mold cavity, which in turn may lead to better yield.