Effect of Cr on the Microstructure and Mechanical Properties of the Al-Cu-Y-Zr Alloy

The present investigation aimed at the determination of Cr addition on microstructure, phase composition, and mechanical properties Al-Cu-Y-Zr alloy. Quasi-binary alloys ternary Al-Cu-Y system with atomic rotation Cu/Y = 4/1 have a narrow solidification range high solidus temperature. 0.3% in Al-5.1Cu-1.7Y-0.3Zr alloy provides formation novel quaternary Al81–85Cu7–10Y3–4Cr5 phase. L12-Al3(Zr,Y) spherical particles diameter 50 nm were nucleated during solution treatment 600 °C. Al7Cr precipitates not found microstructure. main strengthening effect 32.4 MPa 29.1 was achieved from L12 θ’(Al2Cu) precipitates, respectively, accordance calculation. calculated hardness 61.5HV based σy is consistent experimental value hardness. Al3Zr phases should be equilibrium (Al) polythermal section. However, transmission electron microscopy demonstrates Al3(Zr,Y) only. As result, dissolved atom slightly higher rolled annealed AlCuYZrCr A suitable combination strength ductility observed both after rolling subsequent annealing 150 °C for 3 h—the exhibited yield 308–315 MPa, an ultimate tensile 323–335 elongation to failure 2.0–3.3%.