建立了模拟直薄壁件逐点沉积过程中温度场的有限元模型,用等价导热系数和焓值法处理了固-液耦合热传导问题和固液混合区的焓. 模拟结果真实地反映了沉积316L不锈钢直薄壁件的温度场特征. 通过对模拟结果的分析得出, 在高温阶段(700℃以上)熔池的平均冷却速率达到1000 ℃/s数量级, 在240℃以下的冷却速率仅为10 ℃/s数量级. 基板的温度变化经历温度上升、温度平稳、温度下降3个阶段；在温度下降阶段, 基板中的热传导对熔池冷却速率影响很小. 有限元模拟结果与已有文献的实验测量数据吻合很好.
Abstract. RP/M is an advance technology based on build-up and discrete idea, and Laser direct deposition by coaxially feeding the powders to laser melting pool is a RM technology in general use. During depositing metallic components the variation and control of temperature field have been priority research problem in the research works all along, and major research object for this problem is simulating real temperature field during the deposition by finite element method. Finite-element model to simulate the temperature field in depositing process of vertical thin wall samples is created, and Solid-liquid coupling thermal conduction problem and heat content within Solid-liquid dilution zone are treated by use of equivalent thermal conductivity and enthalpy potential method in the paper. The simulating results objectively exposure the characteristics on the temperature field during depositing the vertical thin wall samples of 316Lstainless steel. By means of analyzing the simulation results, it is obtained that mean cooling velocity of the melting pool is at 103℃/S order of magnitude in the temperature upward 700℃，and the cooling velocity merely is at 101℃/S order in the temperature upward 240℃. Fluctuating temperature of the substrate undergoes three stages: elevation, stable, descends, and the thermal conduction in the substrate has little influence on the cooling velocity of the melting pool at the descending period. The conformity of the simulating result data with the experimental findings in public literatures is very well.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] | |
| [10] | |
| [11] |
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