基于传力特性的内高压成形工艺研究进展

Research progress of internal high pressure forming based on pressure-transfer characteristic

内高压成形的零件质量主要根据壁厚均匀性和贴模率进行衡量,壁厚均匀性主要受成形过程中控制材料流动的轴向补料的影响,贴模率主要受成形末期的高压整形效果影响,而影响补料和整形效果的本质因素是内高压成形过程中介质的传力特性。因此,介质传力特性的可调控性是提高内高压成形质量的关键。通过分析水、橡胶和固体颗粒等不同类型介质内高压成形的传力特性,剖析内高压成形的轴向补料机理;通过分析半固态低熔点合金的流变行为可调性,探讨其传力特性和内高压成形工艺的实现方法,以期为形状复杂、大变形和低塑性管件的内高压成形提供参考。

The quality of internal high pressure formed parts is mainly measured according to the wall thickness uniformity and the fitting die rate. The wall thickness uniformity is mainly affected by the axial feeding that controls material flow during the forming process. And the fitting die rate is mainly affected by the high-pressure shaping effect at the end of forming. The essential factor that affects the axial feeding and shaping effect is the pressure-transfer characteristic of the media during the internal high pressure forming process. Therefore,the controllability of pressure-transfer characteristic of the medium is the key to improve the quality of internal high pressure forming. By analyzing the pressure-transfer characteristic of internal high pressure forming with different types of media such as water,rubber and solid granules,the axial feeding mechanism of internal high pressure forming was analyzed;by analyzing the adjustability of the rheological behavior of semi-solid alloy with low melting point,the pressure-transfer characteristic and the realization method of the internal high pressure forming process were discussed to provide a reference for the internal high pressure forming of pipes with complex shapes,large deformation and poor plasticity.