Study On Stretching Technique Of7075Aluminum Alloy Plate

7075aluminum alloy is widely used in the aerospace industry. However, thesubsequent release of residual stress introduced in the quenching process may lead todeformation of the whole aerospace structure parts. Therefore, the decrease orelimination of residual stress in the aluminum alloy plates is very important. The valueand distribution of the residual stress after the quenching process of the aluminum alloyplates is the initial condition to eliminate residual stress and it is also the prerequisite toresearch the mechanical stretching method of eliminating the residual stress.The aluminum alloy plates’ temperature field change in the quenching process, thecauses of thermal stress generation and transformation, the value and distribution of theresidual stress in the course of the quenching process, and the optimum tensile rate ofthe mechanical stretching method to eliminate the alloy plates’ residual stress arestudied, which can provide better reference for the product quality improvement and thesubsequent research work.The main research contents of this paper are as follows:①With the properties of7075aluminum alloy under high temperature considered,the quasi coupling method is used to simulate the quenching process of7075aluminumalloy plates, the temperature field change law and the stress field generation cause andtransformation in the aluminum alloy plates’ quenching course, and the value anddistribution of the stress field left after the completion of the quenching process arestudied, which can provide theoretical support for further residual stress eliminationresearch;②The mechanism of the mechanical stretching method eliminating residual stressin the aluminum alloy plates is analyzed, the finite element method model ofpre-tension process of7075aluminum alloy plates is built, the value and distribution ofthe residual stress after stretching is studied, analysis of the elimination effect by usingdifferent tensile rate stretching is carried out, and the tensile rates of7075aluminumalloy plates are optimized.③Experimental tests of residual stress of aluminum alloy7075plates afterquenching and after stretching are conducted, quenching and stretching operations ofthe7075aluminum alloy test specimen are practiced, the drilling method is applied tomeasure the residual stress after quenching and stretching processes, and the results are analyzed and compared with that of the finite element method simulation, whichvalidate the correctness of the numerical simulation model.