Heat-treatment of2014aluminium alloy forgings with intense strain①
(1. Department of Materials Science and Engineering,
Central South University, Changsha 410083, P.R.China;
2. Southwestern Aluminium Fabrication Plant, Chongqing 401326, P.R.China)
Central South University, Changsha 410083, P.R.China;
2. Southwestern Aluminium Fabrication Plant, Chongqing 401326, P.R.China)
Abstract: The triangular 2014 aluminium alloy forgings with intense strain were made by a variety of heat-treatment processes, and their mechanical properties were measured. The results showed that different solution and aging processes have very strong influence on the mechanical properties of the forgings. The forgings with intense strain from multidirectional deformation (deformation coefficientλ=12), which were solutioned at 500℃for 400 min and aged at 165℃for 10 h, show advanced mechanical properties, and almost no anisotropies. The mechanical properties areσb=466MPa,σ0.2 =454 MPa,δ=10.5% along LD;σb=457 MPa,σ0.2=444 MPa,δ=6.3% along TD;σb=449 MPa,σ0.2=433MPa,δ=4.2% along HD. The yield strength of the forgings made by a new process was improved by 30% to 50%, the ultimate tensile strength by 15% to 30% and elongation by 100% to 200%, compared with the mechanical properties of the forgings made by the traditional process. The investigation indicated that the very fine grains (3~6μm) and the submicrophases(0.05~0.15μm), and their homogeneous distribution have made the forgings have the high mechanical properties.
Key words: 2014 aluminium alloy forgings; intense strain; solution; aging; mechanical properties