Experimental study on multi-pass dieless drawing process of superplastic Zn-22%Al alloy microtubes

The fabrication process of superplastic microtubes using multi-pass dieless drawing is studied experimentally. The superplastic material used in this experiment is a Zn-22%Al alloy tube with an outer diameter of 2 mm and wall thickness of 0.5 mm. A high-frequency induction heating apparatus with an air-cooling nozzle is used for the dieless drawing. As a result, after four-pass dieless drawing, a microtube with outer and inner diameters of 190 and 91 mu m, respectively, is fabricated successfully. It is confirmed that the ratio of inner to outer tube diameters remains a certain constant value in multi-pass dieless drawing. In addition, microtubes fabricated by this process are evaluated by their microstructure and surface roughness. Consequently, it is found that the manufacture of initial tubes with fine grains and high accuracy is essential for fabricating superior micrombes. (c) 2006 Elsevier B.V. All rights reserved.

通过实验研究了利用多道次无模拉拔制备超塑性微管的工艺。本实验所用的超塑性材料是外径为2毫米、壁厚为0.5毫米的Zn - 22%Al合金管。采用带有风冷喷嘴的高频感应加热装置进行无模拉拔。结果，经过四道次无模拉拔，成功制备出了外径和内径分别为190微米和91微米的微管。证实了在多道次无模拉拔过程中，管的内外径之比保持一定的恒定值。此外，通过微观结构和表面粗糙度对该工艺制备的微管进行了评估。结果发现，制备具有细小晶粒和高精度的初始管对于制造优质微管至关重要。（c）2006爱思唯尔有限公司。版权所有。