淬火水温对喷射成形7055铝合金性能的影响

Effect of quenching water temperature on the quenching residual stress, mechanical properties, age-hardening behavior and exfoliation corrosion (EXCO) susceptibility of spray formed 7055 Al alloy was investigated by means of electronic speckle pattern interferometry (ESPI) technique, hardness test, tensile test, EXCO test, and polarization curve diagram. The results show that significant residual compressive stress is formed on the alloy surface after room temperature (25 ℃) quenching, and the maximum residual stress in longitudinal (L) and long transverse (LT) direction reaches up to -352 MPa and -302 MPa, respectively. When the quenching water temperature increases to 60 ℃ or 80 ℃, the maximum residual stress in L direction is reduced by 14% and 25%, respectively, and the maximum residual stress in LT direction is reduced by 12% and 31%, respectively. With the quenching water temperature increases from room temperature to 60 ℃ or 80 ℃, the age-hardening behavior is almost the same, the strength and elongation are changed slightly, the corrosion current density improve, and the EXCO susceptibility is worsen from PB to PC, PC+.