选择性激光烧结翘曲变形抑制工艺

Process study on warp distortion inhibition of selective laser sintering

针对选择性激光烧结(selective laser sintering,SLS)翘曲变形问题,阐述了翘曲变形产生机理,得出主要原因为温度场分布不均匀和烧结层强度不足,确定了预热温度控制和添加工艺支撑两种翘曲变形抑制措施。以悬臂试样为研究对象,设计正交实验,建立了悬臂结构的预热温度与翘曲变形率的二次多元回归模型,确定了合理预热温度工艺参数,结合产品结构特点,基于Magics软件开展了某型液体火箭发动机叶轮工艺支撑设计。结果表明:悬臂试样翘曲变形由6.13%降低至0.5%,产品翘曲变形率由10.31%降低至1.80%,较改进前降低了82.5%,解决了烧结翘曲变形问题。

Aiming at the warp distortion problem of selective laser sintering (SLS), its produce mechanism is descried. Main reasons are the nonuniform distribution of temperature field and the insufficient strength of sintered layer. Preheating temperature controlling and adding technologic support are the key measures to inhibit warp distortion. Taking the cantilever sample as the research object, the orthogonal experiment on the preheating temperature was designed, and a quadratic multiple regression model of the preheating temperature and warp distortion rate was established for the cantilever structure.. Furthermore, the reasonable technical parameters of preheating temperature were determined, and the impeller technical support design of a liquid-fuel rocket engine was carried out by using Magics software combined with the product structure characteristics. The results show that the wrap distortion rate of cantilever sample is reduced from 6.13% to 0.5%, and the wrap distortion rate of product is reduced from 10.31% to 1.80%, which has solved the problem of SLS warp distortion inhibition.