【作者】 格日乐；

【导师】 刘慧敏；

【作者基本信息】 内蒙古工业大学 ， 材料学， 2009， 硕士

【摘要】 原位反应近液相线铸造方法是原位反应与近液相线铸造方法相结合在一起,形成的一种制备半固态坯料的新方法,它将颗粒的生成置于合金熔体中完成,利用半固态坯料的合金相图,在近液相线温度浇铸,得到满足触变成形工艺要求的半固态坯料的一种新型制备方法,它的优点在于原位颗粒表面无污染、在基体中均匀分布、近液相线温度浇铸可以抑制形成枝状晶组织而形成细小的蔷薇状组织,且工艺简单、生产效率高,适用合金品种多。本文采用原位反应近液相线铸造方法,制备出Al₂O₃P/Al-Cu基及Al₂O₃P/Al-Cu-Si基半固态坯料,主要研究制备工艺参数的影响规律,同时利用光学显微镜、透射电镜、X射线衍射等对所制备的Al₂O₃P/Al-Cu基半固态坯料进行微观组织研究。通过试验观察和理论分析得出如下结论:反应的绝热温度从低稀释剂量、高预热温度的一边向高稀释剂量、低预热温度的一边降低;采用镁粉做引燃剂,随着镁粉量的减少,反应诱导时间延长。当原位Al₂O₃颗粒含量达到5.3wt%,熔体温度850℃,预制块的质量成分含量为Al:CuO=1:1,再加入预制块总质量的1/1200的Mg粉时反应进行顺利且不会产生爆炸现象。Al₂O₃P/Al-Cu-Si半固态坯料的反应物配比为Al:CuO:SiO₂=2:3:2,引发剂镁加入量为预制块总质量的1/300,铝熔体温度达到950℃时反应进行彻底。原位Al₂O₃颗粒细小,直径小于0.5μm,弥散分布于基体中,且界面干净,无污染;随着原位反应物加入量的增加,生成的Al₂O₃颗粒增多,但是同时生成的合金元素铜也明显增多,随着含量的增大,CuAl₂在晶粒周围呈网状分布。更多还原

【Abstract】 In-situ reactive Near-liquidus Technology is combined In-situ reactive and near-liquidus method. It is a new method to produce Semi-solid billet. The use of composite alloy phase diagram, Particles will be generated at the completion of alloy melt, then casting in the Near-liqudus temperature. to get the requirements of semi-solid billets of Thixoforming process. Its advantage lies in the surface of the particles in-situ non-polluting, uniformly distributed In the matrix, Dendritic structure is controlled at Near-liquidus casting temperature and some small rose-like organizations are formed,and process is simple, efficiency of the production is high, the multi-alloy of application is varieties.In this paper, in-situ reactive near liquidus casting method is used to prepared the Semi-solid billet of Al₂O₃P/Al-Cu matrix Al₂O₃P/Al-Cu-Si matrix. The influence of process parameters are studies, At the same time, the optical microscopy, transmission electron microscopy, X-ray diffraction is used to research the Semi-solid billet of Al₂O₃P/Al-Cu matrix microstructure. The conclusions can be received through experiments and theoretical analysis:Adiabatic temperature of reaction decreased from low volume, high pre-heating temperature side to the high diluent volume, low pre-heating temperature side; the use of magnesium ignition as the agents , with the reduction in the amount of magnesium, the reaction induction time Extended;When the particle content of in-situ Al₂O₃ come to 5.3wt%, melt temperature 850℃, the quality of block components Content of Al: CuO = 1:1 and then adding the total mass of the preform 1/1200（ Mg powder ）when the reaction was carried out smoothly and does’nt explode. The Semi-solid billets of Al₂O₃P/Al-Cu-Si reactant ratio for Al: CuO: SiO₂ = 2:3:2, initiator of adding Mg is 1/300 of preform, when the aluminum melt temperature reached 950℃, the reaction is exhaustive . The particle of in-situ Al₂O₃ is fine and diameter is less than 0.5μm, dispersing in the matrix and the interface is clean, pollution-free; the Al₂O₃ particles is increased with the in-situ reaction with the addition of materials to generate, but at the same time generate the alloy Elements of copper also increased significantly, with increased content, CuAl₂ was distributed like network around in the grain.更多还原