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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。
The rationality of the die-casting process has an important influence on the mechanical properties of the standard die-casting samples. Flow-3D software was used to simulate and optimize the existing recommended standard sample die-casting process scheme. At the same time, a process scheme suitable for high vacuum die-casting was designed and optimized. The results show that when the existing die-casting process is in the low-speed filling stage, the backflow of liquid metal occurs in the runner near the sample runner. When the transition fillet of the sprue and the runner is increased to 30 mm, the back-flow air-roll phenomenon is significantly reduced. The use of tapered runner and supplemented with buffer package structure, the return flow and the air volume is moved to near the buffer package at both ends, to avoid air metal liquid into the sample cavity, is conducive to improving the quality of the casting. When the exhaust channel is arranged on the side of the sample overflow slot, the sealing phenomenon of the exhaust channel between different samples can be effectively eliminated so as to ensure sufficient time of exhaust after filling the sample, which is favorable for improving the internal quality of the casting.