Tube spinnability of AA 2024 and 7075 aluminum alloys

摘要

Tube spinnability is defined as the maximum thickness reduction before either fracture orbuckling under the given roller geometry, feed rate, and the speed of the mandrel during the tubespinning of a metal. There are two ways employed to experimentally determine the tube spinnabilityof the full-annealed and solution-treated AA 2024 and 7075 aluminum alloys. One is to reduce thethickness stepwise to the final thickness without failure the tube. The other is the one-path spinningwith continuous reduction in wall thickness of preform from initial to the final thickness withoutbuckling to determine the achieved maximum reduction. Using continuous reduction test, thedetermined macro-spinnability of full-annealed AA 2024 aluminum alloys is 75% and 7075 aluminumis 74%. Whereas, when examined by scanning electron microscope, the deformation tongue is visibleon the outer surface as the thickness reduction higher above 50% for both full annealed 2024 and7075 aluminum alloys. However, for both solution-treated 2024 and 7075 tubes, the spinnability islower than that of full-annealed conditions. The discrepancy between the reduction test andmicroscopic spinnability will be discussed in terms of the microstructure and the mechanicalproperties.