For AlMgSi0,7 F27 (6005) type alloy, I wonder about the quenching type of material at the press exit? Is water quenching necessary to catch up the mechanical strength value( it is about 270 MPa(tensile))
Dear Seerix,
ASM Metals Handbook Vol. 4 p.1853 indicates that it might be directly quenched. I would try air-blasting at the exit of the extruder since it is easy to implement. Hardness testing should indicate whether you achieved a proper Mg2Si precipitation or not (around 95 HB).
Take care of the thick sections since the precipitation might be coarse and its distribution poor if enough cooling speeds is not applied.
I hope my note is useful!
ASTM B 807 Standard Practice for Extrusion Press Solution Heat Treatment for Aluminum Alloys is an excellent reference on this subject. Yes, alloy 6005 can be press quenched, as long as the minimum cooling rate is 4 F/second and the time interval from die emergence to quenching is less than a certain amount (depends on thickness). A strong air blast should be able to meet this requirement for thin sections, but for thicker sections a spray of water or water + glycol mixture will be needed. You can obtain the ASTM standard directly from ASTM or from IHS: