Extrusion Die Design for Tubes with Hardness Gradient

• Main Authors: Yu Chen, 陳昱
• Other Authors: Yeong-Maw Hwang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/465d3a

碩士 === 國立中山大學 === 機械與機電工程學系研究所 === 102 === This study is focused on the analysis and experiment of hot extrusion of magnesium alloy. Porthole dies with an inclination angle leads to non-uniform velocity distributions. This kind of design can make a gradient hardness tube that grain sizes at the material surface are smaller and harder than those at the center zone. Then it can have superior hardness on surface and good toughness in internal structure. This study aims to design porthole dies and mandrel with different inclination angles and use magnesium alloy AZ31 to conduct hot extrusion. Mainly in analyze extrusion load, normal plane and bonding plane’s effective strain distributions and material flow by the finite element method. Choose best parameter to manufacture a porthole die to conduct magnesium hot extrusion experiments. Microstructures of the materials are observed to understand the effects of the die inclination angles.