微小型轴向内沟槽铜管缩径缺陷实验研究

Forming defects of axial inner micro-grooved copper tubethrough two-split dies rotary swaging process

二分模旋转模锻工艺是微小型轴向内沟槽铜管(AIGCT)的重要缩径工艺.本文通过实验探讨了两种不同截面尺寸类型(分别记作Ⅰ和Ⅱ)和三种不同的材料属性状态(分别记作:A、B和C)下沟槽管缩径缺陷和缩径进给速率的关系.实验结果表明,A状态Ⅰ型管的伸长率最高可达到20%以上,并随着进给速率的增加而减小;当进给速率超过21mm/s时,在A状态Ⅰ型管的成形区将会产生飞边;当进给速率超过13mm/s时,在A状态Ⅱ型管的成形区将产生凹陷.进给速率超过4mm/s和13mm/s时,将分别会在B状态Ⅰ型管和Ⅱ型管的未成形区产生扭曲.由于存在严重的扭曲和压溃,C状态内沟槽铜管不适合用二分模的方式进行缩径.

In this paper, the two-split dies rotary swaging experiments of axial inner micro-grooved copper tube （AIGCT） are carried out to study the relation of forming defects and feeding rate with two types of cross-sec- tions （ denoted asⅠ and Ⅱ ） and three material states （ denoted as A, B and C） of the tube. The result shows that, the maximum elongation ratio of the A-state AIGCT during rotary swaging may be more than 20%, and it decreases with the increase of feeding rate. It is found that wing can occur on the sizing zone of type I AIGCT in A-state at the feeding rate of more than 21mm/s,and sinking can occur on the sizing zone of type Ⅱ AIGCT in A-state at the feeding rate of more than 13mm/s. When the feeding rate is more than 4mm/s and 13ram/s, twisting will occur on the preform of type [ AIGCT in B-state and type Ⅱ AIGCT in B-state respectively. It is not advisable to form AIGCT in C-state through two-split dies rotary swaging process due to its obvious twisting and compression.