Morphology and wettability analysis of square micropillar structure prepared by laser-belt machining on Inconel 718 alloy surface.

Inconel 718 alloy has high strength and work-hardening characteristics that make the material difficult to machine, and the morphology accuracy is difficult to guarantee. The microstructure of the alloy surface can improve the wettability of the material and affect the functional application of the alloy. In this study, a new process for machining square micropillars on the surface of Inconel 718 alloy using laser vertical cross-scanning technique is proposed—laser-belt machining. The microstructure, roughness, wettability, and chemical composition of Inconel 718 alloy surface were characterized. The results show that the morphological features can be effectively ensured by increasing the laser frequency, increasing the laser scanning pitch and decreasing the laser power. In addition, the capillary forces, nanoparticles, and roughness generated by the square micropillars under the effect of material ablation, thermodynamic processes, and oxidation reactions that make the alloy material surface with better wettability. Compared with other processes, this process has a contact angle of 4.7° under specific processing parameters, achieving a wettability transition from hydrophilic to superhydrophilic (contact angle less than 5°). This study provides guidance on the morphological accuracy and wettability analysis of microstructure surfaces using composite processing technology and provides a new idea for the rapid preparation of microstructure. [ABSTRACT FROM AUTHOR]