Estimating the 3D Printing Defects by Micro-Computed Tomography ^†

Micro-computed tomography (µ-CT) is an X-ray technique with (sub)micron resolution, typically using an X-ray tube with cone-beam geometry as a source and a rotating sample holder. While conventional CT maintained a strong position in life science and low-resolution high-energy CT became widespread in industrial quality control, micro-CT has enjoyed a boost in interest from the materials science research community in the past decade [1]. The purpose of this paper is to present the usage of micro-computed tomography as method to estimate the defects of the 3D-printed items.

A PLA-based compound was shaped as filaments (Figure 1a) with optimal diameter and ovality (Figure 1b) for 3D printing (Figure 1). The identification of the defects of the 3D-printed item was performed by micro-computed tomography. To capture the global image of the 3D-printed sample, a Bruker 2211 nano-computer tomography (nano-CT) equipment was used. The scanning parameters were voltage: 60 kV; current intensity: 150 uA; exposure: 475 ms; resolution: 3 um; rotation step: 0.2 degrees; rotation: 180 degrees. The scanning process did not involve the use of a filter. The resolution of an X-ray was 4904 × 3280 pixels.

The obtained results showed that the defects are placed mainly at the interface between the superimposed layers and in the contact areas with the surface on which the deposit is made.

The versatile and non-destructive micro-CT is a characterization method widespread in industrial quality control. It can also be used for identifying the defects of the 3D-printed items. The obtained results showed that the defects are placed mainly at the interface between the overlayed material and in the contact areas with the surface on which the deposit is made.