耦合攪拌制備7075鋁合金大鑄錠均勻性

耦合攪拌制備7075鋁合金大鑄錠均勻性Uniformity of 7075 aluminum alloy ingot with big size produced by coupled stirring technology

結(jié)合電磁攪拌和機械攪拌，提出一種新型耦合攪拌技術(shù)，并利用該技術(shù)制備直徑為300 mm的7075鋁合金鑄錠，研究該技術(shù)對半連續(xù)鑄造參數(shù)、熔體溫度波動、鑄造液穴、鑄錠組織和成分以及合金流變應(yīng)力的影響。結(jié)果表明:相比普通半連續(xù)鑄造，利用耦合攪拌技術(shù)后，半連續(xù)鑄造工藝參數(shù)范圍擴大，鑄造效率得到提高，鑄造過程中熔體溫度波動由40~50 ℃減小到1 ℃，液穴深度由128 mm減小到88 mm，鑄錠平均晶粒大小減小13%，且偏差由30%減小到9%，成分偏析也明顯減小。此外，合金流變應(yīng)力減小，且鑄錠不同部位的流變應(yīng)力大小差異也明顯減小。耦合攪拌技術(shù)顯著地改善熔體和鑄錠的均勻性。

Combined with the electromagnetic stirring and mechanical stirring, a coupled stirring technology was proposed and used to produce 7075 aluminum alloy ingot with diameter of 300 mm. The effect of the technology on the semi-continuous casting parameters, melt temperature fluctuation, sump, microstructures, compositions of the ingot, flow stresses was studied. The results show that, by the coupled stirring technique, the range of casting parameters expands, the casting efficiency raises, the melt temperature fluctuation decreases from 40-50 ℃ to 1 ℃, the sump depth decreases from 128 mm to 88 mm, the average grain size of ingots decreases by 13%. The deviation of grain size along radius direction decreases from 30% to 9%, and the composition segregation also decreases obviously. The stresses decrease and the differential stress of different parts in ingots decreases remarkably. The coupled stirring technology obviously improves the uniformity of melts and ingots.

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