【作者】 王欢；

【导师】 周建新； 徐进桥；

【作者基本信息】 华中科技大学 ， 材料工程， 2015， 硕士

【摘要】 立式离心铸造作为一种高效的材料成形方法,广泛应用于军事、航空航天等领域。物理模拟可以实现对立式离心铸造充型过程科学定量地分析,摆脱目前工艺生产基于经验的困境,实现智能化的性能预测及工艺优化。本文基于立式离心铸造工艺特点及相似准则,设计开发了立式离心铸造充型过程物理模拟平台。首先本文分析了物理模拟平台开发的理论基础。根据立式离心铸造工艺特点,分析了浇注速度、转速及粘度等工艺参数的选取及影响,阐述了离心力场下流体自由表面形状;利用相似原理,推导出相似准则,确定雷诺数为决定性相似准数。其次本文设计开发了立式离心铸造充型过程物理模拟平台。包括立式离心铸造机、流量控制系统和图像采集系统三大部分。平台可以实现离心转台的无极调速及瞬时转速测定,实现浇注、调速、测速的一体化控制。同时可以实现任意流速的测定及调节,获取流体瞬间充型过程图,为后续流体三维流动分析提供数据支持。最后本文应用该物理模拟平台定性定量地研究了工艺参数对流体充型过程的影响。研究发现充型速度与浇注速度成正比,与转速及时间成反比;粘度越大,充型时间越长。根据相似准则,可以将个别现象推广到与模型相似的一系列实际现象中去,为实际生产提供指导。更多还原

【Abstract】 As a kind of special casting technology, the centrifugal casting is widely applied in fields of military, aviation and spaceflight due to its many advantages. The technique of physical simulation can be used to analyze the productive process of this casting method. It can predict shrinkage defects, optimize casting technology and control the centrifugal casting quality. Based on the vertical centrifugal casting process characteristic and similarity criterion, the vertical centrifugal casting physical simulation platform is designed and developed.Firstly, the theoretical basis of physical simulation platform development is analyzed. According to characteristics of vertical centrifugal casting process, the influence of pouring speed, rotational speed, viscosity and other parameters on the fluid filling process and the shape of free surface under vertical centrifugal field are analyzed. Through the similarity principle, the similarity criterion is derived, the Reynolds number is determined as the decisive similarity criterion.Then the physical simulation platform is designed and developed. The platform includes the vertical centrifugal casting machine, the flow control system and image acquisition system. The platform can enable stepless speed and instantaneous speed measurement. It also can realize integration control of casting, speed regulation and velocity measurement. At the same time, it can realize the arbitrary velocity determination and regulation, obtain the moment of the fluid filling process diagram, provide data support for the subsequent three-dimensional fluid flow analysis.Finally, we use physical simulation platform to study the influence of process parameters on the fluid filling process from qualitative and quantitative. It is found that the filling speed is proportional to the casting speed, and is inversely proportional to the rotational speed and time. The greater the viscosity, the longer the pouring time. According to the similarity criterion, individual phenomenon can be generalized to go with a similar model in a series of real-world phenomena, provide guidance for the actual production.更多还原