Study On The Surface Orange Peel For The Drawing Deformation Of2219Aluminum Alloy

2219aluminum alloy belongs to the series of Al-Cu-Mn which can bestrengthened by heat treatment.2219aluminum alloy is widely used because of highand low temperature mechanical properties, fracture toughness, good resistance tostress corrosion resistance and welding performance. At present, the study about2219aluminum alloy is always focus on the welding performance. The research on thesurface roughening during the drawing forming process is inadequate.In the topic,2219aluminum alloy treated with different heat treatmentprocesses by the change of solution temperature, solution time and quench medium,the best heat treatment condition in which the2219aluminum alloy has goodorganization and performance. The solid solution temperature is at535℃, solutiontime is for30min, quench medium is30%NaCl solution. When the solutiontreatment temperature is below535℃, the strength, hardness and elongation of2219aluminum alloy increase as solid solution treatment temperature increased. At545℃,the strength, hardness and elongation of2219aluminum alloy are falling. In solidsolution treatment, with increasing the solution time for less than30min, the strength,hardness and elongation of2219aluminum alloy increase treatment temperatureincrease. With increasing the solution time mora than30min, the mechanicalproperties of2219aluminum alloy reduce. The strength, hardness and elongation of2219aluminum alloy, increase with cooling speed of the quenching mediumincreased.Measure surface orange peel of2219aluminum alloy with surface roughness(Ra).Discussed the influence of the deformation conditions of2219aluminum alloy andorganizations on its surface orange peel. The relationship between grain size andsurface roughness of2219aluminum alloy is linear; the relationship between surfaceroughness and its deformation is also the approximate linear. The greater thedeformation rate is, the more its surface roughness increased. When the pre-deformation is8%, the surface roughness of the specimen is the lowest.Surface roughening of orange peel phenomenon is as following. In the plasticdeformation, surface defects such as dislocations produced, and then the form crystalslip on the surface. They can lead to the surface micro cracks, finally formed a similar orange peel uneven morphology, produce orange peel phenomenon. Crystal slipmainly depends on the dislocation movement. In the process of deformation, thelarge numbers of dislocations formed, was contributed to the aluminum alloy matrixof slip. When the deformation was large enough, the surface slip band formed. Thesliding is larger in grain, and it is smaller at grain boundary. With the deformationincreasing due to uneven deformation of grains each other, micro cracks formed in thegrain boundary. They can resulted the surface orange of2219aluminum alloy.