Abstract:A numerical approach for process optimization and microstructure evolution of lager-sized forging of aluminium alloy 7050 was proposed, which combined a commercial FEM code Deform 3D with empirical models. To obtain the parameters of empirical constitutive equation and dynamic recrystallization models for aluminium alloy 7050, the isothermal compression tests of 7050 samples were performed on Gleeble-1500 thermo-simulation machine in the temperature range of 250−450 ℃ and strain rate of 0.01−10 s −1 , and the metallograph analysis of the samples were carried out on a Leica DMIRM image analyzer. The simulation results show that the dynamic recrystallization in the central area of the billet occurs more easily than that on the edge. Repetitious upsetting and stretching processes make the billet deform adequately. Among several forging processes e.g. upsetting, stretching, rounding and flatting, the stretching process is the most effective way to increase the effective strain and refine the microstructure of the billet. As the forging steps increase, the effective strain rises significantly and the average grain size reduces sharply. Recrystallized volume fractions in most parts of the final forging piece reach 100% and the average grain size reduces to 10 µm from initial value of 90 µm.
Abstract. At present, haze weather occurs in each big city of China in different extent. The problem of haze has become one of the biggest environmental problems now and the high energy consumption and high pollution industry is the source of haze weather. This paper takes the evaluation of eco-industrial park as the breakthrough point, taking research of high energy consumption and high pollution industries in the main body of the study and putting forward the direction of development about the high energy consumption and high pollution industry in eco-industrial park according to the problem of the research.
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