A novel local heating technique utilizing fiber-laser spot heating system has been developed and adopted to produce the agehardening 2024 aluminum alloy sheets which possess anisotropy in bending properties. Cold rolled sheets of 2024 aluminum alloy of 1.0 mm thickness (80% in reduction) and T3 treated sheets of 0.7mm thickness were prepared and subjected to the laser spot heating in ambient atmosphere at various energy densities varying from 63.7 to 111.4kW/cm2 and heating time of 1, 3 and 5s. The beam size on the focal plane or sample surface was fixed to 200μm in diameter. The spot heating produced recrystallized microstructure, the size of which depends on the irradiation conditions. In the case of 111.4kW/cm2 for 3s, recrystallizes grains appeared in the whole part of sample through the thickness below the irradiation point while part of sample in the vicinity of surface melts yielding a couple of pores. Striped patterns composed of an alternative array of soft and hard region in 0.7mm thick sheets were produced with the present laser spot heating system, and anisotropy of 33.5% in the maximum bending load was obtained when the bending test was performed on the sheets prepared by two types of laser spot heating treatment: one was parallel and the other was perpendicular to the bending axis.
