功率超声对7050铝合金除气净化作用的试验研究  

Experimental Research on the Effect of Power Ultrasonic on the Degassing Process of 7050 Aluminum Melts

作　　者：李晓谦[1] 陈铭[1] 赵世琏[1] 李开晔[1] 吴昊[1] 

机构地区：[1]中南大学机电工程学院,长沙410083

出　　处：《机械工程学报》2010年第18期41-45,共5页Journal of Mechanical Engineering

基　　金：国家重点基础研究发展计划资助项目(973计划;2005CB23707)

摘　　要：通过传振工具杆,分别在不同功率、不同频偏度、不同温度区间对铝合金熔体施加超声振动,利用基于减压原理的HYSCANⅡ测氢仪对每次试验后熔体中的氢气体积分数进行测量,进而探讨超声振动对7050铝熔体除气的影响规律及其作用机制。试验结果表明,经超声处理的铸锭,凝固组织气孔显著减少,铝合金气体体积分数随着超声功率的增加而逐渐减少,共振状态下的超声除气效果明显好于非共振状态,在700～720℃温度范围内的超声除气效率大大高于640～660℃温度范围内的除气效率。超声空化效应对产生大量的空化泡起着关键作用,空化气泡的'表面效应'和'壳层效应'在超声除气过程中起着决定作用。By utilizing the HYSCANⅡhydrogen analyzer to measure the hydrogen content of every experimented melt based on the theory of pressure reduced test,the effect and functionary mechanism of ultrasonic vibration on the degassing process of 7050 aluminum melt are studied by introducing ultrasonic at different ultrasonic power,frequency offset,temperature range through the vibration-transfer tool rod.Experimental results show that the porosities of casting ingot treated by ultrasonic are reduced significantly.The hydrogen content of the melt is gradually reduced with the increase of ultrasonic power.The effect of degassing in the resonance condition is much better than that in the non-resonance condition.The efficiency of degassing between 700 ℃ and 720 ℃ is much greater than that between 640 ℃ and 660 ℃.The cavitation effect plays a key role in producing numerous cavity bubbles.At the same time,the ＂area＂ effect and the ＂shell＂ effect of the cavitation bubble play a decisive role in the degassing process.

关 键 词：除气 HYSCANⅡ测氢仪 空化效应 超声功率 超声频偏度 

分 类 号：TG249.9[金属学及工艺—铸造] TB559[理学—物理]