Surface hardness determination of 3D printed parts using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy was used to determine the relationship between the spectral line intensity and surface hardness of 3D printed 18Ni300 maraging steel. Research found that there is a linear relationship between the spectral intensity ratio of ion line to atomic line and the surface hardness of the samples. This linear relationship is closely related to the selected elements and spectral lines. The weak self-absorption spectrum of minor elements can obtain a better linear relationship. We study the effect of the number of laser pulses on the linear relationship. The results show that the ideal results can be obtained by using 100 pulses, which can minimize the damage to the sample.