The cooling process of the spray-deposited 7055 alloy was simulated by the stepwise insulation process.The precipitation of the second phase in the 7055 alloy was analyzed by XRD

SEM

TEM and other methods.The results show that by the NaOH extraction

η-MgZn

2

phase

S-Al

2

CuMg phase and T-Al

2

Mg

3

Zn

3

phase can be observed in the spray-deposited 7055 alloy.7055 aluminum alloy is the closest to the spray deposition cooling process after 325 ℃ insulation

and some precipitates can be observed such as fineη-MgZn

2

phase

slender S-Al

2

CuMg phase and a plate-like equilibrium phase T-Al

2

Mg

3

Zn

3

phase.Through simulation cooling research

the second phase can be precipitated during the solidification of the alloy

and these second phases is grew into micron-level second phases（η-MgZn

2

phase）during the cooling analysis.The nano-level second phase including the fineη-MgZn

2

phase

the slender S-Al2 CuMg phase and the lamellar equilibrium phase T-Al

2

Mg

3

Zn

3

phase are mainly precipitated during the cooling process.