【作者】 王赟；

【导师】 刘昌明；

【作者基本信息】 重庆大学 ， 材料加工工程， 2005， 硕士

【摘要】 本论文是研究ZL112Y 铝合金的半固态连续触变成形料坯制备工艺,设计一套合适的半固态连续触变重熔装置,以及找到一套合理的连续触变重熔工艺的工艺参数。根据半固态连续触变成形的原理,自行设计了一套实验装置。装置主要包括原始坯料的制备装置以及二次重熔装置。原始坯料是采用低过热法制备,因此坯料制备装置包括熔炼铝合金的电阻炉以及浇注料坯的金属模具。坯料的二次重熔选用感应加热方式,因此二次重熔装置包括用以二次加热的三台感应加热设备及与之匹配的感应线圈、重熔用坩埚、支撑坩埚用的支架以及控制半固态浆料出料的底座。在实验过程中不断的进行了实验装置的改进,包括坩埚的加固、坩埚材料的重新选择以及底座结构的改进。装置设计完后,进行了装置的可行性性验证。经实验证明:1)支架的结构合理,能够实现对感应加热设备及坩埚有序的组装,满足连续式生产的要求;2)感应线圈稳定性好,与感应加热设备能很好的匹配,发挥感应加热设备较大的加热功率;3)控制半固态浆料出料的端座的结构比较合理,能够有效的操控半固态浆料的流出,在端座中采用升热装置后,浆料在流出过程不会发生凝固现象而保持半固态状态。4)整套装置的关键问题在于重熔用的坩锅的选用,经过实验证明,选用的几种坩埚的强度均达不到实验的要求,在高温下出现了裂纹而发生铝液的泄漏,因此坩埚问题还有待改进。为找到一套合理的连续重熔工艺,采用了ANSYS 数值模拟软件进行了坯料在连续触变重熔过程中的温度场分布的模拟。在进行连续触变重熔的模拟前,为了验证模拟的正确性,进行了对原有的最大振荡功率加热、缓慢加热、以及采用优化工艺加热实验的模拟。通过模拟结果与实测结果的对比,证明模拟能够正确的反映坯料在实际加热过程中温度变化的规律,而且模拟得到的坯料温度数据与实测数据基本吻合,误差不大。在进行了细微的材料物理参数修正以及感应加热模型的改进后,进行了半固态连续触变重熔的模拟。通过对在三台感应加热设备不同加热功率匹配下的模拟,找到了坯料由室温加热到半固态过程中各台感应加热设备合理的加热功率以及加热时间。大、中、小功率三台设备的振荡电流值分别为:1350A、800A、600A,加热时间总共为9 分钟,各台感应加热设备的加热时更多还原

【Abstract】 The task of the research is to study the processings of manufacturing thixotropic slurry of the ZL112Y aluminum alloy in continuous semi-solid thixoforming , design a set of logical continuous remelting equipment and look for a set of reasonable heating parameters in continuous remelting processing. According to the principle of the continuous semi-solid thixoforming,a set of experiment equipment was designed. The experiment equipment consists of equipment for preparing the billet and equipment for remelting the billet. As for preparing the billet by the method of low super heat, so the equipment for preparing the billet consists of resistance furnace for melting the aluminum alloy and metallic mould for casting the billet. As for the remelting of billet by the way of induce heating,so the equipment for remelting the billet included three induce heating equipment for remelting billet , the crucible ,the bracket for supporting the crucible, and the pedestal for preventing the outflow of the slurry. The experiment equipment was improved through continuously test. The taken measure was reinforcing the crucible, alterring the material of the crucible and changing the structure of the pedestal. After the experiment equipment was designed, the feasibility of the experiment equipment was studied. Results of the experiment proved that ,1)the structure of the bracket was reasonable as it can well assemble the induce heating equipment and the induce coil and can cater to the need of the continuous production. 2) the stability of the induce coil was fine and the induce coil can well match the induce heating equipment so that the induce heating equipment can work under a condition of a higher power. 3) the structure of pedestal was reasonable as it can effectively control the outflow of the slurry and after a calorific element was used in pedestal,the surry should not freeze and can maintain the temperature of semi-solid during outflow. 4) the main problem occurred in the whole experiment equipment was the selection of the crucible. Results of all experiments shows that all the crucibles choosed cracked under the condition of high temperature and a small quantity of slurry leaked along the crackle. The crucible for remelting needs to be improved. In oder to find a set of reasonable continuous remelting processing, the distributing of the temperature in the billet was simulated by the application of the ANSYS software. In oder to validate the correctness of the simulation ,the induce heating experiment under the condition of greatest vibrant power,slow heating power and opitimized heating parameters was simulated before the simulation of the continuous remelting of the billet .The comparision between the simulated results and the real measured results show well coincidence and the simulated results can correctly reflect the rule of the transformation of temperature in the billet during remelting. After the modification of the physical parameters of ZL112Y aluminum alloy and the mend of the simulation model , the process of continuous remelting of the billet was simulated under different matching mode of three sorts of induce heating power. The reasonable value of power and heating time of each induce heating equipment was achieved and the value of the vibrant current and heating time of each induce heating equipment respectively was 1350A,800A and 600A.The total induce heating time was 9 minutes and the heating time of each induce heating equipment was 3minutes. The comparision between the simulated results and the real measured results show well coincidence. It was tested that the computer simulation was successful and it can be applied to process of the experiment directting the regulation of the power of induce heating experiment and the design of the experiment equipment for semi-solid remelting.更多还原