旋转磁场对铜银合金凝固组织影响研究
时间:2019-10-17 21:02 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：本文主要研究了旋转磁场对铜银合金凝固组织的影响。在铜银合金的凝固过程中，通过旋转磁场的作用，可以显著的使合金组织的晶粒细化，抑制初生相的生长，并且对消除宏观偏析、减小柱状晶的相对体积也有非常好的效果。选取的工艺参数有浇注温度、磁场强度、磁场搅拌时间。实验结果表明：旋转磁场对铜银合金组织晶粒细化效果明显， 使凝固组织原来的粗大的柱状晶变为细小的柱状晶或等轴晶，晶间距离明显减小。更高的浇注温度使金属液体的流动性更强，抑制原子的团聚，使熔体形成更多的形核质心，晶粒更细小。随着磁场强度的增大，旋转磁场产生的洛伦磁力更容易打碎树枝状晶，组织明显细化。磁场搅拌时间越长，增大了热扩散率，使晶核增多，分布均匀，从而细化晶粒，推动柱晶—等轴晶转变。最佳的磁场搅拌工艺参数为：浇注温度 1250℃、磁场强度 180V、磁场搅拌时间 20 秒。 41103 毕业论文关键词：旋转磁场；浇注温度；磁场强度；磁场搅拌时间 Effect of rotating magnetic field on solidification structure of copper and silver alloy Abstract: In this paper, the effect of rotating magnetic field on the solidification structure of Cu Ag alloy was studied. In the solidification process of Cu Ag alloy, through the action of rotating magnetic field can significantly the grain refinement of microstructure, inhibition of primary phase of growth, and to eliminate macro segregation, reducing the relative volume of small columnar crystal also have very good effect. The selected process parameters are pouring temperature, magnetic field strength and magnetic stirring time. The results show that the effect of rotating magnetic field on the grain refinement of Cu Ag alloy is obvious, which makes the original coarse columnar crystals become smaller, and the distance between the grains decreases obviously. The higher pouring temperature makes the metal liquid stronger, inhibits the aggregation of atoms, so that the melt forms more core and the grain is smaller. With the increasing of magnetic field intensity, Lorenz force rotating magnetic field produces more easily broken dendrites, the organization is obviously refined. The longer the stirring time of the magnetic field increases the thermal diffusion rate, makes the crystal nucleus increase, the distribution is even, and the grain size is refined, and the transformation of crystal grain. The best magnetic stirring process parameters are as follows: pouring temperature 1250℃, magnetic field strength 180V, magnetic stirring time 20 seconds. Key words: rotating magnetic field; pouring temperature; magnetic field intensity; Stirring time of magnetic field 目录 1前言 1 11 高速电气化铁路接触线介绍 1 12 高铁用铜合金接触线 1 121 铜银合金接触线 1 122 铜锡合金接触线 1 123 铜镁合金接触线 1 124 新型铜合金接触线 1 13 铜合金接触线生产工艺 2 131 铜锭轧制法 2 132 上引连铸法 2 133 连铸连轧法 2 133 上引连挤法 3 14 旋转磁场对合金凝固组织的影响 3 141 旋转磁场对金属液凝固组织作用机理 3 142 旋转磁场对金属凝固组织细化晶粒的影响 4 15 影响铜合金凝固组织的因素 4 151 浇注温度 4 152 磁场强度 5 153 磁场搅拌时间 5 16 高速铁路接触线的研究进展 5 17 选题的目的和意义 6 18 课题研究的内容和目标 7 181 研究内容 7 182 研究目标 7 2实验 8 21 实验材料 8 22 实验方案 8 221 设计制造一套旋转磁场发生装置 8 (责任编辑：qin) |