论文部分内容阅读
采用气泡搅拌法制备AZ91D镁合金半固态浆料,研究工艺参数变化,包括气体流量、冷却速率和搅拌结束温度,对AZ91D镁合金半固态浆料显微组织的影响规律。结果表明:随着气体流量从0升高至5L/min,α-Mg初生相平均颗粒尺寸从119.1μm降至77.2μm,而平均形状因子从0.1升高至0.596,气泡搅拌中非枝晶初生相来自于枝晶破碎和熔体形核;随着冷却速率从3.6℃/min升高至14.6℃/min,α-Mg初生相平均颗粒尺寸从105.0μm降至68.1μm,而平均形状因子在冷却速率为9.1℃/min时达到最高,过高或过低的冷却速率都会导致初生相的枝晶生长;搅拌结束温度从590℃升至595℃对最终的AZ91D镁合金半固态浆料显微组织无明显影响,这是因为半固态浆料中已经形成了足够数量的初生相。
AZ91D magnesium alloy semi-solid slurry was prepared by bubble mixing method, and the influence of process parameters on the microstructure of AZ91D magnesium alloy semi-solid slurry was studied, including gas flow rate, cooling rate and stirring end temperature. The results show that with the increase of gas flow rate from 0 to 5 L / min, the average particle size of α-Mg primary phase decreases from 119.1 μm to 77.2 μm and the average shape factor increases from 0.1 to 0.596. Phase comes from dendritic crushing and melt nucleation; as the cooling rate increases from 3.6 ° C / min to 14.6 ° C / min, the average particle size of the α-Mg primary phase decreases from 105.0 μm to 68.1 μm while the average shape factor is between The cooling rate reached the highest at 9.1 ℃ / min, too high or too low the cooling rate will lead to the dendritic growth of the primary phase; stirring termination temperature from 590 ℃ to 595 ℃ on the final AZ91D magnesium alloy semi-solid slurry microscopic Tissue has no significant effect because a sufficient amount of primary phase has been formed in the semi-solid slurry.