扩径率和重叠量对机械扩径制品品质的影响

通过有限元数值模拟和实验，研究了扩径率和重叠量对制品品质的影响及其规律。结果表明，扩径率是影响制品横断面尺寸精度的一个主要因素。制品的椭圆度近似为扩径率的三次函数，且在2．0％附近有最小值；壁厚局部变薄量可以近似表示为扩径率的线性函数。扩径率对回弹量的影响和重叠量对制品直线度的影响均不明显。

Influences of Expanding-ratio and Overlap-length on the Quality of Finished Products

The influences of expanding-ratio and overlap-length on the quality of finished product was analyzed systematically by elastic-plastic FEM and expanding experiments. Based on the results,expanding-ratio is important to dimensional precision of finished products. The relation between ellipticity of finished product and expanding-ratio is approximate to a cubic expression,and the minimum can be obtained near 2.0% of expanding-ratio. The local thinning of wall-thickness can be described by linear function of expanding-ratio. It has also a slight influence on the spring-back. The influences of overlap-length on the linearity is unnoteworthy. The most important consideration in choosing parameters was given in the paper.