【摘要】 针对镍基高温合金反重力铸造工艺中传统压力曲线设计方法的不足，充分考虑铸件沿充型方向的变截面结构特征，通过CAD软件的二次开发，实现铸件截面积的自动计算，以定量化描述铸件的截面变化特征。基于伯努利方程和流量守恒方程，推导出充型压力与金属液面上升速度之间的关系，提出基于铸件截面积自动计算的新型压力曲线设计方法。在此基础上，对镍基高温合金铸件的反重力铸造过程进行数值分析。充型模拟结果表明：与传统压力曲线设计方法相比，新型设计方法确定的压力曲线能使最小截面处充型速度峰值由0.611 m/s降至0.439 m/s，降幅达28.15%，有效避免金属液震荡和飞溅；同时可缩短充型时间，确保金属液快速平稳充型。水力学实验和浇注实验表明，新型压力曲线的充型液面更平稳，能有效抑制铸造缺陷，证明新型压力曲线设计方法的有效性，为合理设计反重力压力曲线提供依据。更多还原

【Abstract】 In view of the shortage of conventional design methods of pressure curve in the anti-gravity precision casting and taking the structural characteristics of the casting with variable cross-sections into account,automatic calculation of cross-sectional areas was implemented for the casting and gating system by the secondary development of CAD software,and quantitatively describing the variable feature of cross-sections of casting was realized.Based on Bernoulli and flow conservation equations,the relationship between the filling pressure and the rising speed of metal liquid level was deduced. A new design method of pressure curve based on the automatic calculation of cross-sectional areas of the casting was proposed.The simulation results of anti-gravity casting for nickel-based superalloy demonstrate that, compared with the pressure curve of the conventional design method,the new curve can reduce the peak value of filling speed from 0.611 m/s to 0.439 m/s at the minimum cross-sectional area,the falling range of which is28.15%. It meant that the new method can effectively avoid the shock and splash of liquid metal,meanwhile,shorten the filling time,then the filling process is fast and stable.The hydraulic experiment and pouring experiment show that the new pressure curve has a smoother filling liquid level and can effectively avoid casting defects.Therefore,it proves the effectiveness of the new pressure curve design method and provides a basis for rational design of anti-gravity pressure curve.更多还原