火箭推进

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.

引言
1 SLS技术原理及翘曲变形机理
2 试验研究
3 产品验证
4 结论

图1 成形原理<br/>Fig.1 Forming principle of SLS

图1 成形原理
Fig.1 Forming principle of SLS

图2 翘曲变形力学模型<br/>Fig.2 Mechanical model of warp distortion

图2 翘曲变形力学模型
Fig.2 Mechanical model of warp distortion

表1 PSB粉末特性<br/>Tab.1 Properties of PSB powder

表1 PSB粉末特性
Tab.1 Properties of PSB powder

图3 悬臂试件
Fig.3 Cantilever specimen

表2 因素水平表
Tab.2 Factor-level

表3 试验方案
Tab.3 Test plan

图4 实际烧制悬臂试件<br/>Fig.4 Actual fired cantilever specimen

图4 实际烧制悬臂试件
Fig.4 Actual fired cantilever specimen

表4 预热温度对于翘曲变形率的影响<br/>Tab.4 Effect of preheating temperature on warp distortion rate

表4 预热温度对于翘曲变形率的影响
Tab.4 Effect of preheating temperature on warp distortion rate

图5 预热温度对于翘曲变形的影响 <br/>Fig.5 Effect of preheating temperature on warp distortion

图5 预热温度对于翘曲变形的影响
Fig.5 Effect of preheating temperature on warp distortion

图6 支撑类型及改进效果对比<br/>Fig.6 Comparision of support type and optimization effect

图6 支撑类型及改进效果对比
Fig.6 Comparision of support type and optimization effect

图7 改进前模型三维扫描<br/>Fig.7 Three-dimensional laser scanning result before improvement

图7 改进前模型三维扫描
Fig.7 Three-dimensional laser scanning result before improvement

图8 改进效果对比 <br/>Fig.8 Contrast of improvement effect

图8 改进效果对比
Fig.8 Contrast of improvement effect

表5 工艺改进前后产品型面翘曲变形率对比<br/>Tab.5 Comparison of product warp distortion rate before and after process improvement

表5 工艺改进前后产品型面翘曲变形率对比
Tab.5 Comparison of product warp distortion rate before and after process improvement

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备注

引言

1 SLS技术原理及翘曲变形机理

2 试验研究

3 产品验证

4 结论

期刊信息