Improving the grindability of Inconel 718 by hydrogen embrittlement in ultrasonic-assisted grinding

Inconel 718 has been widely investigated due to its machining properties. The purpose of this work was to investigate a novel proposed grinding technique for Inconel 718 with a combination of ultrasonic-assisted grinding and hydrogen embrittlement (HE) treatment. The technique was hence named hydrogen embrittlement-enhanced ultrasonic-assisted grinding (HEUAG). Before grinding, a thin stress layer was formed on the surface of the workpiece. To reveal its fundamental performance in the grinding of Inconel 718, experiments were conducted to investigate the effect of ultrasonic vibration on the grinding forces and the surface roughness in the presence of hydrogen embrittlement. To investigate the material removal process for HEUAG, single-grit grinding tests were also conducted with hydrogenated samples. Furthermore, the subsurfaces for HEUAG samples were obtained with the transmission electron microscope (TEM) micrographs. The HE treatment reduced the generation of burrs around the scratches and improved the surface quality after grinding.