DEFORMATION LIMITS AND PRODUCT QUALITY IN ROTARY FORMING AND JOINING OF ALUMINUM TUBES

Abstract

Tube forming and joining have now a lot of applications (e.g. mechanical, chemical, weaving, spinning and electronic industries). In the present work, forming and joining of commercial purity Aluminum (99.5%) tubes was investigated using a ball-ended tool on the lathe. Tests included tube end widening, tube end flanging, free (without mandrel) in-section widening, free throttling, and joining an Aluminum tube to a polymer plug. Results showed that in tube end widening, thickness distribution variation improved as the initial tube thickness increased. . In tube flanging, both the initial tube thickness and penetration distance proved to affect the success of the process and regularity of thickness. Joining of two dissimilar materials (polymer core plus Aluminum sheath) was performed successfully. A limit curve could be constructed to forecast the successful material and process variables (expressed by initial thickness and ball diameter) for specified materials, speed and feed in rotary forming. Application of such simple and inexpensive tooling to form and join Aluminum tubes is important, especially for small and medium industries. Altering the design of the tools may help to add a wide variety of applications. It was concluded that Rotary tube end widening on the lathe proved to be a quick and simple forming process. Ball diameter and tube thickness affected the success of the process. As ball diameter increases and tube thickness increases, In tube end widening and flanging, thickness distribution improved as the thickness increased. In flanging, as the thickness and the penetration distance increases, the flange diameter increases. In free section widening and throttling, both initial tube thickness and penetration distance affected the success of the process and regularity of thickness. Joining of two different materials (polymer core plus an Aluminum sheath) was performed successfully on the lathe by a ball shaped tool. Filling and thickness distribution were excellent.