Research On 2219 Aluminum Alloy Rolling And Heat Treatment Process

2219 aluminum alloy has excellent weldability,fatigue resistance performance and corrosion resistance.It has been widely used in the fields of aerospace and spaceflight.Heat treatment and plastic forming are the main strengthening methods for this alloy.It is of great significane to optimize the process parameters of rolling and heat treatment of 2219aluminum alloy.After that,corrosion means were studied and the mechanism of corrosion was explored.The rolling process was studied by controlling variables.The effects of process parameters,including rolling reduction,temperature and rolling rate,on the mechanical properties and microstructures were explored.It was found that rolling reduction and rolling temperature greatly influenced on the microstructures.With the increase of hot rolling temperature from 400?to 420?,and the grains refined and became equiaxed one.At the same time,the tensile strength reached the peak value.When the rolling reduction increased up to 60%,dendritic structure disappeared gradually and the grains were elongated.The optimum process parameters were determined including the rolling deformation of 60%,the rolling temperature of 420?and rolling rate of 0.7S^-1.The effect of pre-deformation degree on the mechanical property and microstructure of2219 aluminum alloy were studied.The results showed that the strength increased firstly and then decrease and the elongation increased persistently with the increase of pre-deformation degree.The large amount of dislocations during pre-deformation processing provided preferential condition for the??precipitated phase.When the pre-deformation increased,the??phases were refined and its amounts increased.The fined and dispersed??phases hindered effectively the movement of dislocations,which enhanced the tensile strength and plasticity of2219 alloy.While strength and the elongation have the same tendency,which increased firstly and then decreased with enlarging the aging time when the pre-deformation reduction is 20%.At last,the effects of pre-deformation reduction on the mechanical properties and microstructures by different corrosion means?Intergranular corrosion,Exfoliation corrosion,Stress corrosion,and Electrochemical corrosion?were studied.It found that different pre-deformation reduction influenced significantly on 2219 aluminum alloy.And the corrosion resistance of the alloy was improved obviously with the increase of pre-deformation degree.OM,SEM?with EDS?,DSC,XRD and TEM were used to observed or study the change of microstructures and precipitated phases respectively.