The 7050 aluminum alloy, of composition shown in Table 1, was used in the experiments. Quenching samples of 40 mm in diameter and 150 mm in height were machined in rolling direction from hot rolled 7050 plates. After solution treated at 470 oC for 30 min, the samples were quickly transferred to the end quenching rig (less than 5 s), as shown in Fig. 1. Spraying pressures used in the exper- iments are 10 kPa, 50 kPa, 100 kPa, 200 kPa, and 300 kPa. The dura- tion of each test was 300 s and the tests were repeated for different flux densities, e.g. 48 L m-2 s-1, 70 L m-2 s-1, 90 L m-2 s-1,