The Corrosive Improvement with High Temperature Laser Surface Treatment of AA7075

a recently developed AA7075 was subjected to solid solution, high temperature laser surface treatment and artificial aging. The microstructure evolution and precipitation behavior were examined, and their effects on corrosion behavior and corrosion cracking were analyzed. The results show that the coarse η phase disappears and a large number of smaller η phases are formed after high temperature laser surface treatment. Most of the phases dissolved into Al matrix during solution, a fine η phase precipitated in laser treatment. η′ appeared in the high temperature laser surface treatment samples. It was concluded that reasonable laser scanning power owned the best corrosion resistance, lower intergranular corrosion tendency. Both lower laser scan power and higher scan power samples were susceptible to the intergranular corrosion, and the intergranular cracking was observed. In contrary, the reasonable sample which the laser power is 1000W showed much better corrosion resistance due to the coarsening and separation of grain boundary precipitations.