Precipitates evolution of the AA7075-H18 alloy sheet during the application of the solution heat treatment process

The hot stamping technology of the high-strength aluminum alloy sheet has attracted increased attention from both the scientific community and industry due to the rapidly growing demand for lightweight automobiles. However, the development of a proper solution process suitable for the hot stamping technique remains a great challenge. Along these lines, in this work, the precipitates evolution of the AA7075-H18 alloy sheet with a thickness of 2 mm during the implementation of the solution process was systematically studied. The insoluble particles (i.e., Al23CuFe4 and Mg2Si) and the soluble particles (η-MgZn2) were clearly identified from the aluminum matrix. Moreover, the transformation sequence during the solution heat treatment was determined, and a reasonable solution temperature window was also established.