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I milled some 6061 T6 aluminum into some long flat tapered wedges, 0.040 inch on the thick end to 0.005 inch over a span of 20 inches, and they curled when I released them from my fixture. I tried different tool geometries, speeds, feeds, and depths of cuts. Do you have any suggestions?
Response from Boeing’s Research & Technology group
It sounds like you are using material that is not stress-relieved. 6061 T6 is in the "quenched and aged" condition. I would recommend buying material in a stretched condition (6061 T651) and making sure to machine equal amounts of material from both sides in order to balance the stresses.