SLS成形件的收缩模型和翘曲模型

Model of Shrinking and Curl Distortion for SLS Prototypes

快速成形的精度是快速成形技术发展和扩大其应用领域的关键 ,工艺误差是影响成形精度的关键之一 ,而成形件收缩和翘曲对其工艺精度起决定性的作用。通过建立 SL S成形过程的收缩模型研究了 SLS加工中成形件的收缩形式以及收缩规律 ,同时研究了收缩的不均匀性所引起的翘曲 ,建立了成形件的翘曲模型。发现烧结收缩与烧结程度密切相关 ,翘曲量与烧结收缩率成正比 ,与零件线尺寸成正比。这些研究结果为克服 SL S加工收缩引起的误差和收缩补偿提供了依据 ,为减少翘曲变形提供了一种方法。

RP accuracy is a critical factor influencing the RP development and a main impediment in the expansion of its application fields.Technological error is also one key factor influencing the accuracy of RP. The technological error is mainly caused by the shrinkage and curl distortion. In this study, shrinkage forms and shrinking rules in SLS prototypes were investigated after establishing the shrinkage model and the curl distortion resulted from non-uniform shrinkage is investigated after establishing the distortion model. It concluded that the sintering shrinkage is related tightly to the sintering extent of powder and the volume of distortion is proportional to shrinkage and the linear dimension of the sintering parts.This can provide a method for compensating and reducing shrinkage and a method for reducing curl distortion.