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提出一种半固态制浆的新方法即局部强冷超声均匀法。以镁合金AZ91D为实验材料,采用正交实验法,结合凝固组织形成非枝晶及细晶组织的机理,研究在间隙式局部强冷和超声介入条件下半固态制浆的效果和相关因素对其的影响,结果表明,在局部强冷及超声介入条件下,熔体中能发生大量非自发形核,并且以球状方式生长;浇注温度为620℃、超声功率为600W时,分别在弱、中和强喷雾条件下,可获得5℃~25℃的过冷度,制备出初生相α晶粒等效圆直径为27μm~48μm、晶粒形状因子约为1.46的半固态浆料。其中中等喷雾条件下,实验结果最优。该方法为解决熔体均匀过冷形核和非枝晶生长提供了一种新的视角。
A new method of semi-solid pulping is proposed, that is, local strong cold ultrasonic homogenization. Taking magnesium alloy AZ91D as experimental material, the effect of semi-solid pulping under interstitial local strong cold and sonication conditions and the related factors were studied by orthogonal experiment combined with the mechanism of solidified tissue forming non-dendritic and fine-grained microstructure. The results show that a large amount of non-spontaneous nucleation occurs in the melt and grows in a spherical manner under local strong cold and ultrasonic conditions. When the pouring temperature is 620 ℃ and the ultrasonic power is 600W, Under the conditions of neutralization and strong spraying, the undercooling degree of 5 ℃ ~ 25 ℃ can be obtained, and the semisolid slurry with the equivalent circle diameter of primary crystal α of 27μm ~ 48μm and the grain shape factor of about 1.46 was prepared. Medium spray conditions, the experimental results of the best. This method provides a new perspective to solve the problem of uniform supercooled nucleation and non-dendritic growth.