论文部分内容阅读
鉴于液态补缩机制不能解决大高径比铸件中心缩孔疏松缺陷,提出了固态补缩机制.通过分析金属液静水拉力对内孔形核和固相屈服变形的作用,阐明了固态补缩机制的原理,并得出了影响铸件固态补缩能力的主要因素:液体破裂压力值、金属液气体含量以及固相屈服强度.在此基础上,提出了降低铸件在径向上的温度梯度是减少大高径比铸件缩孔疏松缺陷的有效方法.最后,设计了铸件在不同模具温度下凝固的验证实验,证实了固态补缩对于减少大高径比铸件缩孔疏松的作用.
In view of the fact that liquid-filled mechanism can not solve the defects of shrinkage porosity in the center of large diameter ratio castings, a solid-state packing mechanism is proposed.By analyzing the effect of hydrostatic tension on the nucleation and solid-state yielding deformation, The main factors influencing the ability of solid casting to shrink are obtained: the value of liquid rupture pressure, the content of liquid metal gas and the yield strength of solid phase.On this basis, it is proposed to reduce the temperature gradient in the radial direction of the casting to decrease greatly High diameter ratio castings shrinkage porosity loose defects effective method.Finally, the design of the casting in different mold temperature solidification validation experiments confirmed the solid state shrinkage for reducing the large height diameter than the shrinkage of the role of casting.