Pipe reduction of miniature inner grooved copper tubes through rotary swaging process

细小内沟槽铜管的回转模锻管端缩径(英文)

A rotary swaging machine was applied to fabricating pipe reduction for miniature inner grooved copper tube （MIGCT） heat pipes. Compared with conventional swaging method, the axial feed of the designed rotary swaging machine was reached by a constant pushing force. The deformation of grooves in pipe reduced section during rotary swaging was analyzed. The shrinkage and extensibility of pipe reduction were measured and calculated. Furthermore, four aspects, including outer diameter, surface roughness, extensibility and processing time of pipe reduction, which were influenced by the pushing force, were considered. The results show that the tube wall thickness increases gradually along the z-axis at sinking section. However, the outer diameters, surface roughness and micro-cracks at reduced section tend to decrease along the z-axis. Besides, the effect of variation in the pushing force on the extensibility is limited while an increase in the pushing force results in a decrease of surface roughness. Therefore, a large pushing force within the limit is beneficial to pipe reduction manufacturing during rotary swaging process.

为制造小型沟槽铜热管,设计和采用了回转模锻工艺进行管端缩径。相比传统的回转模锻,所使用的回转模锻机的轴向进给通过恒定的推力实现。采用实验方法,分析旋转模锻过程中缩径段的沟槽变形,测量和计算管端缩径过程的截面收缩率和伸长率。探讨进给推力对缩径段的直径、表面粗糙度、伸长率和加工时间的影响。结果表明:缩径段的管壁厚度沿着轴向逐渐增长,而外径、表面粗糙度和微观裂纹则沿轴向逐渐减小。此外,推力对伸长率的影响很小,而表面粗糙度则随着推力的增大而减小。因此,采用回转模锻进行管端缩径,在允许范围内,增大进给推力对管端缩径质量有益。