弛豫铁电单晶炉的设计与模拟
发布时间：2018-09-15 18:57
【摘要】：近年来随着铁电单晶在超声医学、传感器、水声换能器的广泛应用,生长尺寸大,性能稳定的铁电单晶成为研究的重点领域。目前生长铁电单晶的方法主要有高温溶液法,降温法和布里奇曼法,其中又以布里奇曼法生长出的铁电单晶尺寸较大,性能较稳定。但是,在铁电单晶生长过程中存在着组分偏析、熔体对流等因素以至于生长出的铁电单晶无法达到预期。因此,开展铁电单晶生长设备温度场的模拟和分析以及磁场对铁电单晶生长作用的影响,对生长更大尺寸,更好性能的铁电材料研究具有重大的意义。本文的工作分为三部分：第一是对铁电单晶生长炉炉体结构的设计,第二是基于设计的炉体结构对炉体温度场的模拟,其中温度场模拟又分为横向温度场的模拟和纵向温度场的模拟。第三是设计合理磁场结构以达到在炉体内部引入一定强度的磁场的目的,并对引入磁场的强度进行有限元模拟和分析。上述工作得出如下结果：设计了三段式的铁电单晶炉。炉体高度为1082mm,炉体直径402mm,保温层厚度为280mm。高温段高度为300mm,加热组件是硅钼棒。中温段高度为200mm,加热组件是电阻丝。低温段为300mm,加热组件是电阻丝。用ANSYS有限元模拟软件对铁电单晶生长炉的横向温度场进行了模拟,得出温度在径向的分布曲线,发现该曲线是非线性的；有限元模拟得出在炉体外壳处的温度为108.65℃,此温度是后续磁场结构设计及磁铁材料选择的主要考虑因素。用ANSYS有限元模拟软件,在降温法生长铁电单晶的条件下对单晶生长炉纵向温度场进行了模拟,得出轴向温度分布曲线,通过对模拟数据的提取,得出炉体以一定速率降温时1032℃等温面和1265℃等温面的位置-时间关系曲线都是非线性的。针对本文设计的炉体结构设计了两种磁场结构,利用Femm有限元分析软件对两种磁场结构进行了模拟。一种结构是无铁厄的磁环,模拟结果显示在中心处可以产生约420mT的均匀磁场。另一种结构是有铁厄的磁环,模拟结果显示在中心处可产生160mT的均匀磁场。
[Abstract]:In recent years, with the wide application of ferroelectric single crystals in ultrasonic medicine, sensors and underwater acoustic transducers, ferroelectric single crystals with large growth size and stable performance have become the focus of research. At present, the main methods of growth of ferroelectric single crystals are high temperature solution method, cooling method and Bridgman method. Among them, the size of ferroelectric single crystals grown by Bridgman method is large and the properties are stable. However, in the growth process of ferroelectric single crystals, there are some factors, such as component segregation, melt convection and so on, so that the growth of ferroelectric single crystals can not meet the expectations. Therefore, the simulation and analysis of the temperature field of ferroelectric single crystal growth equipment and the effect of magnetic field on the growth of ferroelectric single crystal are of great significance to the study of ferroelectric materials with larger size and better performance. The work of this paper is divided into three parts: the first is the design of the furnace structure of ferroelectric single crystal growth furnace, and the second is the simulation of the furnace body temperature field based on the designed furnace structure. The simulation of temperature field is divided into the simulation of transverse temperature field and the simulation of longitudinal temperature field. The third is to design a reasonable magnetic field structure to achieve the purpose of introducing a certain intensity of magnetic field in the furnace body and to simulate and analyze the intensity of the magnetic field by finite element method. The results are as follows: a three-stage ferroelectric single crystal furnace is designed. The height of furnace is 1082 mm, the diameter of furnace is 402 mm and the thickness of insulation layer is 280 mm. The high temperature section height is 300 mm, the heating module is silicon molybdenum rod. The height of the middle temperature section is 200 mm, and the heating module is a resistance wire. The low temperature section is 300 mm and the heating module is resistance wire. The transverse temperature field of ferroelectric monocrystalline growth furnace was simulated by ANSYS finite element simulation software. The temperature distribution curve in radial direction was found to be nonlinear, and the temperature at the furnace shell was 108.65 鈩，
本文编号：2244189
[Abstract]:In recent years, with the wide application of ferroelectric single crystals in ultrasonic medicine, sensors and underwater acoustic transducers, ferroelectric single crystals with large growth size and stable performance have become the focus of research. At present, the main methods of growth of ferroelectric single crystals are high temperature solution method, cooling method and Bridgman method. Among them, the size of ferroelectric single crystals grown by Bridgman method is large and the properties are stable. However, in the growth process of ferroelectric single crystals, there are some factors, such as component segregation, melt convection and so on, so that the growth of ferroelectric single crystals can not meet the expectations. Therefore, the simulation and analysis of the temperature field of ferroelectric single crystal growth equipment and the effect of magnetic field on the growth of ferroelectric single crystal are of great significance to the study of ferroelectric materials with larger size and better performance. The work of this paper is divided into three parts: the first is the design of the furnace structure of ferroelectric single crystal growth furnace, and the second is the simulation of the furnace body temperature field based on the designed furnace structure. The simulation of temperature field is divided into the simulation of transverse temperature field and the simulation of longitudinal temperature field. The third is to design a reasonable magnetic field structure to achieve the purpose of introducing a certain intensity of magnetic field in the furnace body and to simulate and analyze the intensity of the magnetic field by finite element method. The results are as follows: a three-stage ferroelectric single crystal furnace is designed. The height of furnace is 1082 mm, the diameter of furnace is 402 mm and the thickness of insulation layer is 280 mm. The high temperature section height is 300 mm, the heating module is silicon molybdenum rod. The height of the middle temperature section is 200 mm, and the heating module is a resistance wire. The low temperature section is 300 mm and the heating module is resistance wire. The transverse temperature field of ferroelectric monocrystalline growth furnace was simulated by ANSYS finite element simulation software. The temperature distribution curve in radial direction was found to be nonlinear, and the temperature at the furnace shell was 108.65 鈩，
本文编号：2244189
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