An experimental study on the quality of flow-formed AA6061 tubes

Flow-forming is one of the effective processes for manufacturing thin-walled seamless tubes. Experiments were performed on annealed AA6061 tubing preform to produce seamless thin-walled tubes. The final dimensional accuracy and the surface quality achieved for various levels of process parameters were examined. It has been found that a number of factors affect the quality and dimensional precision of flow-formed tubes. In this investigation, the effects of these process parameters on the quality of flow-formed tubes are discussed and the optimum process parameters for good surface characteristics are proposed. Preforms annealed for 90 min were found to possess good surface property. A depth of cut of 2 mm and a feed in the range of 50-100 mm/min produced tubes of sound surface characteristics. It was found that a minimum gap is required between the mandrel and the workpiece to avoid diametral growth. (C) 2007 Elsevier B.V. All rights reserved