Abstract
Powder-bed fusion additive manufacturing technology makes it possible to produce parts with complicated geometry and high accuracy. However, dimensional deviation caused by powder overmelting and dross formation is still a challenge for manufacturing thin channels. In this study, we analyzed the origins of the overmelting of printed thin channels and propose a concept called "melting cell" to describe and quantify the geometric error. Based on the geometrical relationship between the melting cell and target channel, a method for predicting and optimizing the final geometry of thin channels is outlined. In order to verify the method, geometries of thin horizontal circular channels of various sizes are studied as examples. The predicted results by the proposed method show a remarkable agreement with available experimental results. Moreover, a mathematical description of the compensated design of a thin channel is also presented. The proposed method is simple yet effective. It can be easily extended to manufacturing of thin channels with various shapes, materials, and different powder bed fusion processes.