Hot Extrusion Process of Magnesium Alloy Sheet Under Converging Die

• Main Author: 周村憲
• Other Authors: 向四海
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/61001003155159072097

碩士 === 國立臺灣科技大學 === 機械工程系 === 91 === Most parts of Mg Alloys are produced by die casting in industry. In general, products of die casting tend to have inferior mechanical properties compare with the forged parts. Furthermore, SF6, which has a strong global warming potential in environmental issues, is required as a protective gas in the die casting process. It is desirable to form the Mg alloys under hot extrusion having good mechanical properties and without any possible danger to the environment. During the hot extrusion of magnesium alloy, its structure is HCP, which has fewer slide surfaces than aluminum alloy. Experimental results show that if the hot extrusion of magnesium alloy sheets is performed under a die that has a high extrusion ratio of 35.9, and a fixed speed is adopted, all the final products carry defects. Further experiments are performed on the extrusion of magnesium alloy sheets by the multi-speed method , sound sheets can be obtained. In this study, using Taguchi experimental method , the experimental sequence is planned. Through ANOVA technique and from the test results of extruded material we can find the relationship between the process parameters and the mechanical properties of the products. Then the optimal combination of process parameters can be found.