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采用华铸CAE软件,对客车的球墨铸铁轮毂铸件的凝固过程进行了数值模拟,根据对铸造工艺方案的凝固模拟和实验结果分析,获得了1种合适的铸造工艺用于轮毂铸件生产,有效地消除了轮毂生产过程的缩孔、缩松缺陷。 相似文献
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利用华铸CAE软件对球墨铸铁过桥箱铸造工艺的充型及凝固过程进行了模拟,分析了铸件可能产生的缺陷。根据模拟结果,对铸造工艺方案进行了优化。通过放置冷铁和改善浇注系统,使铸件实现顺序凝固,消除了缩孔缺陷,提高了铸造过桥箱的质量和工艺出品率。 相似文献
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在分析了铸件凝固过程结晶潜热释放和缩孔、缩松形成条件后,应用数值模拟软件模拟了砂芯铸造汽轮机阀体的凝固过程,得到阀体铸件凝固的温度梯度分布,并预测了铸件出现缩松、缩孔缺陷的部位。在此基础上,对铸件凝固过程进行了阐述。数值模拟结果可供阀体铸造工艺设计参考。 相似文献
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H. B. Wu Z. T. Fan N. Y. Huang X. P. Dong X. F. Tian 《Journal of Materials Engineering and Performance》2005,14(1):132-135
The magnesium (Mg) alloy low-pressure expendable pattern casting (EPC) process is a newly developed casting technique combining
the advantages of both EPC and low-pressure casting. In this article, metal filling and the effect of the flow quantity of
inert gas on the filling rate in the low-pressure EPC process are investigated. The results showed that the molten Mg alloy
filled the mold cavity with a convex front laminar flow and the metal-filling rate increased significantly with increasing
flow quantity when flow quantity was below a critical value. However, once the flow quantity exceeded a critical value, the
filling rate increased slightly. The influence of the flow quantity of inert gas on melt-filling rate reveals that the mold
fill is controlled by flow quantity for a lower filling rate, and, subsequently, controlled by the evaporation of polystyrene
and the evaporation products for higher metal velocity. Meanwhile, the experimental results showed that the melt-filling rate
significantly affected the flow profile, and the filling procedure for the Mg alloy in the low-pressure EPC process. A slower
melt-filling rate could lead to misrun defects, whereas a higher filling rate results in folds, blisters, and porosity. The
optimized filling rate with Mg alloy casting is 140 to 170 mm/s in low-pressure EPC. 相似文献
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运用Procast软件对某铝合金筒体的差压铸造方案进行模拟优化。通过分析充型和凝固过程的温度场,发现在筒体的厚壁部位易出现缩孔、缩松缺陷。经过优化计算,通过提高模具预热温度和厚大部位刷导热涂料,实现了铸件的顺序凝固,提高了成品率,获得了理想铸件。 相似文献
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应用两相流模型模拟压铸充型过程的卷气现象 总被引:1,自引:0,他引:1
通过对压铸充型过程中卷气缺陷形成机理的分析,认为型腔中空气的流动以及与金属液之间的相互作用是形成卷气现象的主要原因.为了考虑型腔中空气的流动,采用了一种不可压缩两相流数学模型来模拟压铸充型过程的卷气现象.通过计算流体力学中的两个基准算例,较为全面地验证了该模型的准确性和可靠性.在此基础上,设计了专门针对压铸充型过程的高速水模拟实验,通过对可视化实验结果与两相流模拟结果的比较,证实二者吻合较好,说明了该模型能够较好地模拟液体的充填行为和卷入其中的气泡. 相似文献
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Mensuration and simulation of mold filling process in semi-solid die-cast of aluminum alloy 总被引:1,自引:0,他引:1
To understand the flow trace of semi-solid slurry in mold cavity, some thermocouples were inserted in mold cavity, and the reaction timing of thermocouples showed the arrival of fluid. The filling time and rate were estimated by comparison between the experiment and calculation. The introduction of computer simulation technique based on ADSTEFAN was to predict injectionforming process and to prevent defects during trial manufacture of various parts. By comparing the formed appearance of parts in experiment and in simulation, and observing the relationship between internal defects inspected by X-ray or microscope and the flow field obtained in simulation, it was indicated that both have quite good agreement in simulation and experiment. Right predictions for cast defects resulted from mold filling can be carried out and proper direction was also proposed. The realization of numerical visualization for filling process during semi-solid die-cast process will play an important role in optimizing technology plan. 相似文献
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《中国铸造》2019,(3)
Die casting process is widely applied in making Al parts. However,due to high speed of liquid metal flow in the die cavity,gases are prone to be entrapped in the filling,resulting in porosity defects. The X-ray computed tomography scanning technique was used to detect the pores in die-cast ADC12 alloys with different intensification pressures. The three-dimensional features of pores including pore size,number,sphericity have been obtained. The effect of different intensification pressures on two different kinds of pores,namely gas-pores and shrinkage pores,was analyzed. The results show that with increasing the pressure,the pore fractions and quantity gradually decrease. When the pressure increased to 85 MPa,the pores from gas entrapment during the mold filling were compressed,leading to a lower porosity fraction. The pressure cannot affect the pores in the samples with a thin wall(2 mm) due to a great solidification rate. 相似文献
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Ti-6-4合金熔体离心铸造过程中流态分析 总被引:4,自引:2,他引:2
针对金属型离心浇铸Ti6Al-4V(Ti-6-4)合金人工骨关节,对其充型过程进行了理论分析,得出了熔体离心充型过程中的层流判据以及熔体自由面仍的变化规律,结果表明,离心力场下,熔体充型时可保持的层流长度随转台转这的提高而减小;熔体自由表面将发生倾斜,最终趋于竖直,此外,讨论了离心力场下铸件内部卷入性气孔和偏中心线缩松的产生原因及分布规律。 相似文献
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在试制铝合金半固态压铸汽车零件过程中,引入计算机模拟技术用于充型过程的预测与缺陷的预防,实现了充型工艺系统的优化设计。通过实样压铸的成形外观和模拟结果以及内部缺陷的无损探伤和模拟的流场相比较,均表明模拟与实际结果符合良好。计算机模拟,对于充型过程所可能伴随的铸造缺陷可作出较为准确的预测,并提出改进的方向。通过实现半固态压铸的高速压射过程的数值可视化,对工艺方案和工艺过程的优化将有很好的参考作用。 相似文献