Effects of laser processing on Nickel Oxide - Yttria stabilized zirconia

Laser based additive manufacturing techniques such as selective laser melting (SLM) and selective laser sintering (SLS) have been gaining much attention in recent years due to their ability to create complex shapes and designs from layers of powdered materials. These two technologies although similar in mechanisms, vary in their use of laser systems due to the difference in materials used. A material's absorptivity at different wavelengths will affect the amount of energy transferred by the laser to that material. In this study, a ceramic composite material, Nickel Oxide - Yttria Stabilized Zirconia (NiO-YSZ), which is commonly used as an electrode in solid oxide fuel cell applications was analyzed using two different laser systems. Carbon dioxide laser (10.6 μm) was found to be better absorbed by NiO-YSZ as compared to fiber laser (1.06 μm) through observation of the microstructure after laser processing. Due to poor absorptivity of NiO-YSZ at 1.06 μm, only liquid state sintering between the particles was observed, while at 10.6 μm, eutectic microstructures was evident after laser processing demonstrating that melting of NiO-YSZ had occurred. With increasing laser power used, amount of eutectic microstructure within the processed region was also increased and becomes more aligned. This paves the way of using laser parameters to control the microstructure of a desired structure at each layer.