Ultrafast development of blue pigment for in situ laser digital coloration in the ceramic industry

Abstract This study presents a fast and simple method for digital ceramic coloration using inkjet printing, eliminating the need for traditional precalcined pigments. This innovative approach represents a breakthrough in ceramic decoration technology, and introduces a previously unexplored methodology. In this work, CoAl₂O₄ spinel, a pigment commonly used in industrial contexts, is synthesized through laser zone melting (LZM) by applying pulsed laser radiation at 1064 nm. A standardized methodology to optimize pigment quality is developed, based on laser parameters such as pulse width, frequency, speed, power, and line spacing. Scanning electron microscopy (SEM) is used to determine the optimal laser conditions for obtaining a continuous, defect‐free coating, showing that the embedded particles on the surface exhibit a nearly spherical morphology with diameters below 100 nm. The sample with the highest surface quality is further analyzed structurally and optically. X‐ray diffraction (XRD) confirms the presence of a pure spinel phase without secondary phases, along with a vitreous phase due to pigment embedding. Fourier‐transform infrared spectroscopy (FTIR) and Raman spectroscopy reveal the characteristic vibrational bands of a normal spinel structure. The intense blue color is confirmed by strong absorption at 560 nm in ultraviolet–visible (UV–Vis) spectroscopy, as well as b * and Δ b * values of 29 and 1.58, respectively, compared to the traditional pigment. This synthesis approach significantly enhances digital ceramic coloration compared to other methods evaluated in this study, offering a scalable, flexible, and more efficient alternative suitable for industrial‐scale production.