Comparative Analysis of Vaporization Rates of 5456 Aluminum Alloying Elements during CO_2 Laser Welding

摘要

In this paper, the vaporization rates of Mg~(2+) and Al~+ alloying elements of a 5456 aluminum plate were investigated using the CO_2 laser welding process. The models proposed and used by Block-Bolten and Eagar in 1984 and Zhao and DebRoy in 2003 were applied with experimental results generated from this study. The vaporization rate of Mg~(2+) ions and Al~+ ions using the equations proposed by Block-Bolten and Eagar gave 8.76 μgs~(-1)cm~(-2) and 0.0465 μgs~(-1)'cm~(-2) respectively, whereas the equation proposed by Zhao and DebRoy gave 6.7 μgs~(-1) cm~(-2) and 0.016 μgs~(-1) cm~(-2) respectively. These values are within the reported values obtained by Block-Bolten and Eagar (1984). The heat transfer coefficient for Mg~(2+) and Al~+ ions were also obtained. The vapor bubble radius including the surface tension and buoyancy forces were examined. The evaporative power and energy losses as a result of these bubbles' collapse were calculated. The paper clearly shows the comparative analysis of alloying elements' vaporization process in the aluminum metal heating process.