摘要
在不同的温度以及不同的初始含氢量下对A356铝合金熔体实施超声振动,通过定量测氢仪直接测定含氢量,研究了超声振动在制备半固态A356浆料时对熔体含气量的影响及除气效果。结果表明,对A356液相线温度(615℃)以下20℃以内的半固态浆料,超声振动具有除气作用,最大除气率达15%左右。初始含氢量低时,半固态熔体的超声除气效率降低。熔体氩气除气结合半固态超声振动除气效果最好,含氢量可降至0.12cm3/100gAl以下。对在常压下制备的液态及半固态浆料凝固试样,气缩孔率随熔体含氢量的降低而减小,试样密度随含氢量的降低而增大。
The melt of A356 alloy was treated by ultrasonic vibration under different temperature and different initial hydrogen content.Through direct measurement of hydrogen content in the melt,the influence of ultrasonic vibration on gas content in the melt and degassing efficiency was studied during the preparation of A356 semi-solid slurry.The results show that ultrasonic vibration has degassing effect when the temperature of the semi-solid slurry is lower than the liquidus temperature in less than 20 ℃,and the maximum degassing efficiency is around 15%.When the initial hydrogen content is low,the degassing efficiency of the semi-solid slurry decreases.Combining argon degassing with ultrasonic vibration under semi-solid temperature,the degassing effect is best,and the hydrogen content can decrease below 0.12 cm3/100 g Al.For samples made under atmosphere,with the decrease of hydrogen content in the melt,the pinhole and shrinkage porosity rate decreases,the density increases.
出处
《热加工工艺》
CSCD
北大核心
2010年第19期19-23,共5页
Hot Working Technology
基金
国家自然科学基金项目(50775086)
国家863计划项目(2007AA03Z557)
关键词
超声振动
半固态
铝合金
含氢量
除气
ultrasonic vibration
semi-solid
aluminum alloy
hydrogen content
degassing
