摘要
压铸工艺方案的合理性对标准压铸试样的力学性能具有重要影响。采用Flow-3D软件对现有推荐的标准试样压铸工艺方案进行了模拟分析和优化;同时设计和优化了适于高真空压铸的工艺方案。结果表明,现有的压铸工艺方案在低速充填阶段时,试样内浇道附近的横浇道中会出现金属液回流卷气现象。将直浇道与横浇道的过渡圆角加大到30mm时,该回流卷气现象明显减小。改用锥形横浇道并辅以缓冲包结构时,回流和卷气部位则移至两端的缓冲包附近,可避免卷气的金属液进入试样型腔中,有利于铸件品质的改善。采用在试样溢流槽侧面设置排气道时,能有效消除不同试样间排气道的封闭现象,从而保证后充填试样有足够的排气时间,有利于铸件内部品质的提高。
Rationality of gating system in the die casting process has great effects on the mechanical properties of the standard casting samples. The Flow-3D software was employed to analyze and optimize the existed gating system of standard samples. Meanwhile,design and optimization of high vacuum die casting for standard samples were conducted. The results show that gas entrapment and liquid alloy backflow occurred around the runner nearby the ingate during slow speed filling stage in the existing die casting process. And they could be significantly reduced with the transition angle between the sprue and the runner increasing to 30 mm,while tapered runner with buffer structure was adopted,the backflow and gas entrapment can be moved to the packet buffer,and the liquid metal with gas entrapment can be avoided before moving into cavity,which is beneficial for the improvement of die castings quality. Air vent located in the side of the overflow can effectively eliminate the blockage of exhaust passage among different samples,which ensures adequate exhausting time after the samples are filled completely. Therefore,the internal quality of the castings is improved.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2011年第10期939-942,共4页
Special Casting & Nonferrous Alloys
关键词
压铸
(高)真空压铸
标准试样
浇注系统
数值模拟
Die Casting
High Vacuum Die Casting
Standard Samples
Gating System
Numerical Simulation
