Papers by Keyword: Aluminum Alloy Thick Plate

Abstract: A discretization method is used in pre-stretching simulation to separate an aluminum alloy thick plate into layers. When the equivalent plastic strain in each layer is defined according to the residual stresses during quenching, the yield strength model can be developed to estimate its yield strength. Again, the curve of elasticity modulus is fitted in the light of the experimental data, which can reveal how the elasticity modulus changes with plastic deformation. Finally, in consideration of the non-uniformity of yield strength and elasticity modulus, the pre-stretching of the quenched 7075 aluminum alloy thick plate is taken as an example to numerically simulate the value and distribution of residual stresses at the pre-stretching ratio of 1.8%, 2.2% and 2.5%, respectively. It is known from the simulated results that, by using the proposed method in this paper, the obtained results of the distribution and magnitude of the residual stresses are in good agreement with the experimental measurements.

Abstract: The residual stress distributions of 7075 aluminum alloy rectangular thick plates after quench-hardening had been simulated firstly, then all the results were presented and compared with each other. Some deep theoretical analyses were also carried out. The results show that complicated residual stress distribution regularities in aluminum alloy thick plates can be obtained by the finite element analysis successfully.

Abstract: The level and distribution of residual stresses have great impact on dimensional stability, while Vibratory Stress Relief (VSR) is an effective technology to relax or homogenize residual stresses. Experimental study on residual stresses distribution, residual strain energy and machining deformation of 7075 high-strength aluminum alloy thick plate under different aging process status shows that VSR can effectively decrease the amplitude and strain energy density, and enhance stability of dislocation structures and phase states in metal microscopic volume, then internal residual stresses are homogenized to enhance components’ anti-deformation capacity. In addition, the capability in maintaining dimensional stability from VSR is better than that from traditional mechanical stretching process

Abstract: A new high frequency induction brazed monolayer diamond wire saw for cutting aluminum alloy thick plate is developed with the helical continuous cutting edge distance on the wire surface. In order to solve the problems of forming cutting aluminum alloy plates,the brazed diamond wire saw is used to conduct the preliminary cutting tests on the 50 mm aluminum alloy plates on the modified grinder experimental platform.The results indicate that the cutting efficiency of the brazed diamond wire saw is increased with the increasing of the feed tension, the wire saw line speed and the diamond grits size. Furthermore, some cutting chips shape of the aluminum alloy is presented based on experimental cutting.

Abstract: It’s necessary to research and analyze the correctness of internal stress measurement, in order to effectively deal with the measurement problem of stress field and rightly describe the distribution character of stress in aluminum alloy thick plate. Firstly, the total uncertainty of stress calculation in layer removal method (LRM) is determined by experimental error and model error, and less than ±10MPa, in which the accuracy of experiment is high. Secondly, in the integral calculation of LRM, a modified function is proposed by the multi-methods of simulation and experiment, and can compensate the deviation resulted from unpredictable error for experimental conditions. Then the multi-methods achieve the value of X-ray surface stress, simulation calculation and experimental results to consistent, the correctness of experimental calculation is enhanced. The research presents that the LRM can exactly describe distribution of internal stress in thick plate under special experiment conditions.

Abstract: To predict the three-dimensional residual stress distribution of 7075 aluminum alloy thick plates, the quenching and pre-stretching process were simulated by using MARC finite element software. In order to simulate quickly according to different reality conditions, the parametric model was realized by using defining parameters and selecting objects by inputting coordinate value with the box mode. In the quenching process, a non-linear thermo-mechanical direct coupled analysis of the aluminum alloy thick plates was carried out, by taking into account of the temperature dependence of the thermo-physical properties. In the pre-stretching process, the clamp and release of the clamp of pre-stretch machine were simulated by using life and death element technology. The study demonstrates that the theoretical predictions agree well with the experimental values of residual stresses measured by the X-ray diffraction method. The simulation results provide the user a tool for analyzing and studying on quenching and pre-stretching technique using virtual reality method.