Microstructural Characterization and Mechanical Property of Al-Li Plate Produced by Centrifugal Casting Method

Using a centrifugal casting method, along with deformation and aging, we produced a high-strength, low-anisotropy Al-Li plate. The electron probe microanalysis, transmission electron microscope, differential scanning calorimetry, and X-ray diffraction were used to clarify the evolution of strengthening phases. Experimental results showed that centrifugal-cast Al-Li plate consisted of intragrain delta '-(Al,Cu)(3)Li precipitate and interdendritic theta '-Al2Cu particles. After cold-rolling to a reduction ratio of 60% and annealing at 800 K for 90 min, both primary theta ' and delta ' were dissolved in solid solution. Aging at 438 K for 60 h led to the formation of two kinds of precipitates (needle-like T-1-Al2CuLi and spherical delta ' in two sizes), which acted as the main strengthening phases. The average values of ultimate tensile strength and yield strength for the anneal-aged plate reached 496 MPa and 408 MPa, with a total elongation of 3.9%. The anneal-aged plate showed mechanical anisotropy of less than 5%. The tensile fracture morphology indicated a typical intergranular fracture mode.

Automated summary

Through centrifugal casting method, a high-strength, low-anisotropy Al-Li plate was successfully produced, and the evolution of strengthening phases was clarified using advanced analysis techniques. The plate exhibited excellent mechanical properties after deformation, annealing, and aging treatments, with an ultimate tensile strength of 496 MPa and a yield strength of 408 MPa.