高分子粉末SLS过程的温度场与热变形分析

Temperature and Heat Deformation of Polymer Powder During SLS Process

针对高分子粉末选择性激光烧结(SLS)的特点,应用数值方法与物理实验研究了ABS粉末烧结过程的温度场演化以及制件的热变形。研究发现,对于特定粉体材料,不同时刻的温度分布主要取决于热源的移动状态。不同烧结路径热量叠加状态的不同,造成各点温度峰值的差异。温度的突变与分布不均是导致材料不均匀热膨胀和收缩,从而产生热应力和制件翘曲变形的重要因素。对于各种几何形状的制件,可以通过优化烧结路径使温度场分布均匀,从而减少制件的整体变形。

According to the character of selective laser sintering（SLS）process of macromolecule powder,temperature distribution evolvement and thermal deformation of SLS parts of ABS powder were studied by numerical and experimental method.It was found that for given material,the temperature distribution along different sintering path and in different moment mostly rely on the movement of thermal resource,and the heat overlay in different path would lead to different of temperature peak value.The sudden change and uneven distribution of temperature made the material expand and shrinkage unevenly,which became an important factor of thermal stress within the material and warpage of the part.For different shapes of parts,the overall distortion can be decreased by optimizing the sintering path when even distribution of temperature was obtained.