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采用Procast铸造模拟软件,模拟了高Nb-Ti Al合金低压涡轮叶片离心铸造过程。在其他工艺参数一定的条件下,研究不同离心转速对叶片充型、凝固过程的影响。模拟结果显示,离心转速越大,叶片中缩孔缩松缺陷体积越小,所生产的铸件越致密。但是,当离心转速达到500 r/min时,金属熔体主要由上部横浇道注入,与两端同时注入方式相比,浇注效率低,而且气体不易排出,容易产生卷气缺陷。并且离心转速大会增加金属熔体对型腔壁的冲刷作用,容易产生夹砂缺陷。综合考虑,最终本模型的最佳离心转速确定为400 r/min。
Procast casting simulation software was used to simulate the centrifugal casting of high-pressure Nb-Ti Al alloy turbine blades. Under certain conditions of other process parameters, the effects of different centrifugal speeds on filling and solidification of leaves were studied. Simulation results show that the greater the centrifugal speed, the smaller the volume of shrinkage defects in the blade, the more dense the castings produced. However, when the centrifugal speed reaches 500 r / min, the molten metal is mainly injected through the upper runner. Compared with the simultaneous injection at both ends, the molten metal has low pouring efficiency and the gas is not easily discharged, so that the air-entanglement defect easily occurs. Centrifugal speed and the General Assembly to increase the metal melt on the cavity wall erosion, prone to nip defects. Taken together, the optimal centrifuge speed for this model was finally determined to be 400 r / min.