共查询到18条相似文献,搜索用时 671 毫秒
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镁合金薄板快速铸轧过程有限元仿真研究 总被引:2,自引:1,他引:1
为了研究铸轧工艺参数对AZ31镁合金薄板快速铸轧过程温度场和热应力场的影响,基于铸轧区板坯的对称性建立了纵截面1/2的二维几何模型;选择了基于热弹塑性增量理论的热应力控制方程;采用大型通用有限元分析软件ANSYS对镁合金快速铸轧过程中的铸坯温度场和热-应力场进行了仿真分析,并就不同工艺参数(浇注温度、接触界面换热系数、铸轧速度)对铸坯温度和应力的分布及其相变区的影响进行了研究。仿真结果增强了对镁合金快速铸轧过程相变区温度变化和热裂产生机制的理解,为快速铸轧工艺参数的优化提供了依据。 相似文献
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AZ31镁合金薄带铸轧温度场的数值模拟 总被引:1,自引:0,他引:1
借助ANSYS软件下的Fluent模块模拟了AZ31镁合金铸轧区的温度场,研究了AZ31镁合金薄带铸轧时不同工艺参数下铸轧区的三维温度场的分布,分析了温度场的分布对薄带铸轧过程稳定性的影响。通过对比分析模拟结果,给出在所选取范围内最佳工艺参数是,浇注温度为853K,铸轧速度为9m/min,冷却水流速为3m/s。 相似文献
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《特种铸造及有色合金》2016,(2)
铸轧区的温度分布是影响铸轧过程的稳定性和复合带材质量的重要因素。根据流体力学及双辊铸轧技术的特点建立了数学模型,运用Fluent软件对碳钢-不锈钢固液复合铸轧进行了模拟计算,得到了不同浇注温度和铸轧速度下熔池内温度场的变化情况,分析了浇注温度、铸轧速度分别对温度场的影响情况,此模拟可预测不锈钢水凝固前沿的位置,为双辊固液复合铸轧工艺的进一步研究提供借鉴。模拟结果表明,铸轧速度对熔体温度分布的影响要大于浇注温度。当浇注温度为1 803K,铸轧速度为6m/min时可保证铸轧稳定进行。 相似文献
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基于现有的制备纤维增强铝基复合材料的方法,提出了一种连续纤维增强铝基复合材料板带铸轧控制成型方法。建立连续纤维与液态铝复合成型的分析模型,得到铝液的流动速度和铸轧辊与铝液间的换热系数对纤维增强铝基复合材料板带铸轧过程中铝液的流场、温度场和凝固场的影响。数值模拟结果表明:在铸轧区内,铝液温度快速下降,温度值快速达到固相线以下,流动速度变得很小;随着拉速增大,速度变化剧烈程度增大,铝液凝固速度变小,在同一点处的温度值增大;随着换热系数的增大,温度值减小,凝固速度加快,在同一点处的温度值减小,液相率降低。 相似文献
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《中国有色金属学会会刊》2022,32(8):2569-2577
A new severe plastic deformation method for manufacturing tubes made of AZ31 magnesium alloy with a large diameter was developed, which is called the TCESE (tube continuous extrusion?shear?expanding) process. The process combines direct extrusion with a two-step shear?expanding process. The influences of expanding ratios, extrusion temperatures on the deformation of finite element meshes, strain evolution and flow velocity of tube blanks during the TCESE process were researched based on numerical simulations by using DEFORM-3D software. Simulation results show that the maximum expanding ratio is 3.0 in the TCESE process. The deformation of finite element meshes of tube blanks is inhomogeneous in the shear?expanding zone, and the equivalent strains increase significantly during the TCESE process of the AZ31 magnesium alloy. A extrusion temperature of 380 °C and expanding ratio of 2.0 were selected as the optimized process parameters from the numerical simulation results. The average grain size of tubes fabricated by the TCESE process is approximately 10 µm. The TCESE process can refine grains of magnesium alloy tubes with the occurrence of dynamic recrystallization. The (0001) basal texture intensities of the magnesium alloy tube blanks decrease due to continuous plastic deformation during the TCESE process. The average hardness of the extruded tubes is approximately HV 75, which is obviously improved. 相似文献
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在对镁合金发动机缸体压铸件进行工艺分析的基础上,通过应用正交试验方法,并使用模拟软件对金属液的充型和凝固过程进行数值模拟。结合各组试验所得的不同数据,确定了压铸件生产的优化工艺参数:模具预热温度为220℃,浇注温度为670℃,压射速度为8.5m/s,并确定了工艺参数对铸件缺陷的影响顺序。且在该组优化的工艺参数下,通过对金属液的充型和凝固过程的动态观察,预测充型时间、凝固时间和可能存在的缩松、缩孔及气孔缺陷的分布与体积分数。实现了发动机缸体压铸工艺参数的优化。 相似文献
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Hai-liang Yu Qing-bo Yu Jin-wu Kang Xiang-hua Liu 《Journal of Materials Engineering and Performance》2012,21(9):1841-1848
Magnesium alloy strips are widely used in aerospace, automotive industry, etc., which are difficult to produce through cold forming process due to their poor deformation ability. In this article, we studied whether the rolling process with heated roll could be used to roll cold magnesium alloy strips. Thermal-mechanical finite element simulation of the rolling process, using heated roll and cold strips to produce the magnesium alloy strips, was carried out. Influences of roll temperature, rolling velocity, rolling reduction ratio, and initial strip thickness on the thermal field and the mean temperature of magnesium alloy strips were analyzed. Both the heated area in strips in rolling deformation zone and the mean temperature of strips at exit of rolling deformation zone increase with increasing the roll temperature and/or rolling reduction ratio, and/or with decreasing the rolling velocity and/or initial strip thickness. Finally, a formula was developed to predict the mean temperature of strips under different rolling conditions, which also could be used to calculate the critical value of parameters in rolling process. 相似文献
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浇铸温度与模具温度对AZ91D和Mg-3Nd-0.2Zn-Zr镁合金热裂性能的影响(英文) 总被引:1,自引:0,他引:1
研究了浇铸温度和模具温度两个温度参数在重力金属型铸造中对商业AZ91D和新型Mg-3Nd-0.2Zn-Zr(质量分数,%;NZ30K)镁合金热裂性能的影响。结果表明,模具温度对合金热裂性能的影响比浇铸温度的更显著,后者的影响仅在模具温度较低时(AZ91D在341 K,NZ30K在423 K)有所显现。与只包含补缩参数的热裂模型相比,同时包含补缩参数、晶粒尺寸和合金凝固区间的热裂模型更能够准确地评价不同镁合金的热裂性能。为了获得较好的热裂抗力,建议AZ91D合金的浇铸温度为961~991 K,模具温度≥641 K;NZ30K合金的浇铸温度为1003~1033 K,模具温度≥623 K。 相似文献
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In this paper, the effects of pouring temperature of magnesium melt, preheating temperature of the barrel of the screw mixer, and shear rate on the solidified microstructures of semi-solid slurry were investigated by a mechanical stirring semi-solid process. The appropriate processing parameters of slurry preparation were obtained, and the mold filling ability of semi-solid slurry for thin-walled casting was examined. Results indicate that the solid volume fraction of non-dendritic microstructure increases with a decrease in pouring temperature of magnesium melt and the barrel preheating temperature of the screw mixer. Also the grain size of primary α-phase is reduced. Furthermore, the solid volume fraction of semi-solid nondendritic structure decreases with an increase of shear rate. The fine and round granular microstructure with 30~50 μm in size of semi-solid AZ91D magnesium alloy was presented. Finally, a 1.0 mm thin-walled casting with a clear contour and good soundness was successfully made by semi-solid rheo-diecasting. 相似文献