中文摘要：

为提高等温挤压成形件的尺寸精度和减少试模次数,利用弹性力学厚壁圆筒理论拉美（Lame）方程、塑性力学应力-应变本构方程,针对轴对称结构的整体凹模和二层组合凹模,建立了等温挤压成形过程中模具变形、热膨胀和材料回弹等各因素对成形件尺寸偏差影响的数学模型,确定了对等温挤压成形模具型腔尺寸修正的总偏差。对具体零件的等温挤压成形进行实验验证,采用所提出的模具型腔尺寸修正方法设计出的等温挤压成形凹模获得的成形件的尺寸相对偏差小于0.2%,为等温成形模具型腔尺寸的设计提供了参考和一种较为实用的修正方法。

英文摘要：

To improve the dimensional accuracy of isothermal extrusion part and reduce the mold trial times,by using the Lames equation of thick walled cylinder theory and stress-strain plastic constitutive equation,the mathematical models of dimensional deviation caused by the factors such as die deformation,thermal expansion and springback of forming parts during isothermal extrusion were established for axial symmetrical integral die and two layers combined die.The total dimensional deviations of the isothermal extrusion die cavity were derived.Via the experimental verification,it is found that the relative dimensional deviations of the formed parts can be controlled within 0.2% by isothermal extrusion die designed according to the proposed die cavity dimensional modified method.The dimensional correction method provides reference and practical method for cavity dimensional design of isothermal extrusion die.