Effects of supergravity on composition and microstructure of gradient Al-Zn-Mg-Cu alloy

A new method for the preparation of gradient Al-Zn-Mg-Cu alloy was presented in this paper. The composition content, microstructure and mechanical properties in gradient combined with the directional solidification process were obtained by optimizing the experimental parameters under conditions of hypergravity cooling centrifugation. Based on the precipitation characteristics of the alloy, the efficient separation of α-Al precipitated phase and eutectic T phase during cooling and solidification was realized by supergravity technology and temperature gradient range, in which most of the α-Al precipitated phrase was concentrated at the top of the sample, while the eutectic microstructure was mainly distributed at the bottom of it. Increasing the gravity coefficient and expanding the temperature gradient was beneficial to obtain materials with a larger gradient range, owing to the precipitated phases with different densities distributed at different positions of the sample under the supergravity. The results showed that the gradient aluminum alloys could be obtained in a short time by supergravity cooling centrifugation, thus providing new process means and ideas for the preparation of the gradient aluminum alloy materials.