超声振动对半固态铝合金浆料含气量的影响
Influence of Ultrasonic Vibration on Gas Content of Semi-solid Slurry of Al Alloy
马倩倩, 吴树森, 毛有武, 朱泽明
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作者单位:华中科技大学 材料成形与模具技术国家重点实验室,湖北 武汉 430074
中文关键字:超声振动; 半固态; 铝合金; 含氢量; 除气
英文关键字:ultrasonic vibration; semi-solid; aluminum alloy; hydrogen content; degassing
中文摘要: 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0.12 cm3/100 g Al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。
英文摘要: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.