Influence of 3D printing stress wave on residual stress

Abstract

As a popular rapid manufacturing technology, three-dimensional printing (3D printing) has been widely adopted in medical, automotive, aerospace, construction and other industrial fields. The stereo lithography apparatus (SLA) is an effective 3D printing method for ceramic printing. However, shrinkage from monomer to polymer and laser stress wave cause residual stress in the formed parts during SLA. Serious quality defects including cracks, warpage and deformation caused by residual stress have remained to be a problem. Basically, the laser stress wave plays an important role in the generation of 3D printing residual stress. In this work, to investigate the propagation mechanism of the laser stress wave, the finite element method was adopted to simulate the SLA process of zirconia. The influence of 3D printing factors on the residual stress was obtained, and we found that the wave velocity of the stress wave obtained by the simulation model was highly consistent with the theoretical wave velocity. Meanwhile, the attenuation formula of the stress wave in the 3D printing process was obtained by fitting to investigate its attenuation law. Based on the above results, the attenuation law of the 3D printing stress wave has a direct influence on the development and variation trend of its residual stress.