Application method of novel 3-series aluminum alloy (Al-0.8%Mn) etchant solution

The invention discloses an application method of a novel 3-series aluminum alloy (Al-0.8%Mn) etchant solution. The application method is characterized by comprising the steps that 1, the etchant solution, having the ratio of 1 ml of HF, 2 ml of HCl,2.5 ml of HNO3 and 94.5 ml of H2O, is prepared; 2, a 3-series aluminum alloy (Al-0.8%Mn) sample is ground and polished; 3, the 3-series aluminum alloy (Al-0.8%Mn) sample is blown and dried through hot air blown by an electric hair drier, the surface of the sample is cleaned up through industrial alcohol, and corrosion begins; 4, the etchant solution is dropwise sprayed on the surface of the 3-series aluminum alloy (Al-0.8%Mn) sample and wiped with a cotton ball continuously, and the corrosion time ranges from 45 s to 55 s; 5, the 3-series aluminum alloy (Al-0.8%Mn) corroded by the etchant solution is cleaned through the industrial alcohol; and 6, the 3-series aluminum alloy (Al-0.8%Mn) is blown and dried, and the metallographic structure can be observed.