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为了研究不同热边界条件对熔积直接成形金属零件翘曲变形的影响,运用有限元法建立了三维模型,通过变换冷却和加热条件来分析直壁件熔积成形过程在不同热边界条件成形过程中温度、应力变化和最终翘曲变形.模拟结果表明:熔积过程中运用随焊冷却技术,能使熔积层温度迅速降到接近环境温度,并在随后的时间内保持很低的温度梯度,从而减小了冷却阶段的应力水平,使得翘曲变形量降低;而熔积成形前对基板预热处理会增加热积累和温度梯度,导致残余应力及翘曲变形量的增加.
In order to study the influence of different thermal boundary conditions on the buckling deformation of the metal parts directly melted, the three-dimensional model was established by using the finite element method. The cooling and heating conditions were used to analyze the forming process of the wall- Temperature, stress change and final warp deformation.The simulation results show that the use of welding with the cooling technology in the melting process can make the temperature of the molten layer drop rapidly to near ambient temperature and maintain a very low temperature gradient in the following time , Thus reducing the stress level in the cooling stage and reducing the warpage. Preheating the substrate before the deposition process will increase the thermal accumulation and temperature gradient, resulting in the increase of residual stress and warpage.