Development of High Strength Wrought Aluminum Base Alloys

摘要

Work is reported on small-scale laboratory techniques for development of high strength wrought aluminum alloys, and on structure and properties of alloys produced. Highest tensile strengths obtained were in excess of 115,000 psi; highest yield strengths were in excess of 110,000 psi. Four different alloys tested showed yield strengths in excess of 90,000 psi with elongations in excess of 5%. All testing was on flat specimens machined from rolled sheet. The sheet was produced from cast ingots. The ingots employed as starting material were thin section rapidly solidified plates. The rapid solidification produced a dendrite arm spacing that was sufficiently fine (approximately 8 microns) that complete homogenization was feasible in a reasonable time. Plates were fully homogenized before rolling. In initial stages of the alloy development, a levitation melting and 'splat cooling' device was used to permit rapid determination of (1) maximum alloy contents that could be employed while still retaining a single phase at solution temperature, and (2) optimum solution treatment temperature. Dendrite arm spacing in these splats was 1-2 microns. (Author)