Extruded and a drawn aluminum tube differentiation
Extruded and a drawn aluminum tube differentiation
(OP)
Is it possible to differentiate between an extruded and a drawn aluminum tube by a metallurgical examination of the microstructure? I do not know if the tube has been artificially aged after drawing / extruding. Surface finish is smooth and shiny ID and OD with some longitudonal marking.





RE: Extruded and a drawn aluminum tube differentiation
http://www.welding-advisers.com/
RE: Extruded and a drawn aluminum tube differentiation
RE: Extruded and a drawn aluminum tube differentiation
RE: Extruded and a drawn aluminum tube differentiation
Extrusion of Al tubing is done hot as part of the heat treatment process. E.g., 6061 exits the extrusion die at the solutionizing temperature, then is water sprayed & cooled prior to artificial aging to T6. Not shiny.
RE: Extruded and a drawn aluminum tube differentiation
Yes, it is possible to differentiate tubes produced by the two different processes. If you obtain both a transverse and a longitudinal cross-section and etch them appropriately, the microstructure will reveal whether or not the parts were cold drawn, etc. Goahead correctly pointed out that extruded tubes will show a recrystallized microstructure. Cold drawing will obviously change this microstructure. Macroetching may also be useful. ASM HANDBOOK Volume 9 [I/Metallography and Microstructures[/I] is an excellent reference on the subject.