Research On Horizontal Continuous Casting Of Al-1%Si Alloy Treated With Power Ultrasound

As an important branch of ultrasound, power ultrasound studies energy effect of ultrasound. Power ultrasound is applied to change some properties of materials, or accelerate the changes by ultrasonic energy. It is a new high technology based on physics, mechanics, electronics, materials and so on, and applied widely, mainly including ultrasonic aid material product, ultrasonic cleaning, ultrasonic jointing, ultrasonic medicine and ultrasonic chemistry.The paper mainly researches on the effect of power ultrasound to Al-Si alloy solidification during horizontal continuous casting. Ultrasonic treatment is one of the most effective methods to improve solidification structures and mechanical properties of casts. Early in 1935, Sokolov studied pure metal's solidification with ultrasonic vibrating apparatus. With ultrasonic treatment, the homogenous and refining structures can be obtained.Al-l%Si alloy is the main bonding materials of integral circuit and semi-conduction apparatus. With the trend of downsizing and higher integrality of apparatus and the increasingly bonding speed and complexity, Al-1%Si alloy bonding wires of high-quality are needed. In conventional production, rupture often occurs due to the defects of cast ingots, which has become a bottleneck to enhance the production efficiency. Therefore, it is significant to develop a new process to produce high-quality Al-1%Si cast ingots.The paper betters the design of experimental apparatus and parameters of horizontal continuous casting of Al-l%Si alloy. The effects of power ultrasound on the surface quality, solidification structures and mechanical properties of Al-l%Si alloy are investigated. The results show the application of power ultrasound makes the distripution of melt temperature more homogenous and the surface quality of cast ingots better, increases the nucleation rate, refines alloy structures, suppresses boundary segregation of Si element, and improves the mechanical properties of Al-1%Si alloy.Ultrasonic cavitation can break down the primary crystal and the dendrite. With the stirring of acoustic streaming, particle crystal is dispersed in melt, increasing the number of external nucleus and refining grains.