中文摘要：

以Al-K2Ti F6为反应体系,采用电磁搅拌法制备了原位Al3Ti/ADC12复合材料半固态浆料,研究了不同搅拌参数对该复合材料半固态组织的影响,揭示了半固态组织在电磁场作用下的演变机理。结果表明在本实验降温搅拌过程中,随着搅拌时间的逐渐增加,该复合材料半固态组织中的初生α-Al相形貌发生了多样性变化,经历了树枝状、蔷薇状、近球状的演变,其中在585℃时水淬取样的组织较佳,初生α-Al相主要呈近球状,弥散悬浮于液相中,平均尺寸约为35.2μm。在一定范围内,若固定相同的搅拌频率和搅拌时间,在降温搅拌过程中,随着搅拌电压的增大,晶粒形貌趋于圆整,尺寸逐渐变小;若固定相同的搅拌电压和搅拌时间,在降温搅拌过程中,随着搅拌频率的增大,晶粒逐渐细化而后又逐渐增大。

英文摘要：

Semi-soli d slurry of in-situ Al3Ti/ADC12 aluminum matrix composite was synthesized by electromagnetic stirring in the system Al-K2 Ti F6. The effects of stirring parameters on the semi-solid structure of the composite were investigated. The evolution mechanism of semi-solid microstructure in the electromagnetic field was revealed. The results show that the morphology of primary α-Al phases in semi-solid microstructure of the composite has multifarious transformation with the increase of stirring time during hypothermia stirring. The morphology of α-Al particles is confirmed to evolution into dendrite, rosette or near sphere. When the temperature of water quenching is 585℃, the semi-solid microstructure of the sample is better, the primary α-Al phases become mainly near-spherical shape, which is well-suspended in the liquid phase, then, the average diameter is 35.2 μm. In an appropriate range, crystal grains are tended to be round and fine with the accumulation of stirring voltage if stirring frequency and stirring time are fixed during hypothermia stirring. The average diameter of particles reduces first and then begins to increase with the accumulatation of stirring frequency if stirring voltage and stirring time are fixed during hypothermia stirring.