Study on machinability and grain deformation of laser cladding manufactured and wrought IN718 alloys in dry milling process

The technique of laser cladding (LC) has gained tremendous attention for its potential to replace conventional machining procedures for producing and repairing intricate components based on Inconel 718 (IN718) alloy. Nevertheless, the application of LC fabricated IN718 components is often limited because of their mediocre surface integrity and mechanical property, these components need to be post-treatment. Post-treatment with dry milling not only improves surface quality but also contributes to environmental protection. Therefore, to get insight into the material removal mechanism of LC fabricated IN718 components in the dry milling process, a range of experiments have been conducted to research cutting force, surface topography and roughness, subsurface microstructure, and microhardness. A set of comparative trials to the wrought IN718 samples were also performed. The cutting forces of LC fabricated IN718 samples are 1.52-16.69 N larger than that of wrought IN718 samples, owing to differences in grain geometries. Also, relatively typical surface topography and roughness were achieved using different kinds of IN718 samples. There is evidence that surface plastic deformation and grain refinement are greater on LC fabricated IN718 samples than on wrought IN718 samples. Finally, examinations of the subsurface microstructure and microhardness between the two types of IN718 samples were compared. Grain refinement in two types of IN718 components could increase microhardness from 92.1 to 140 HV0.025.

Automated summary

The technique of laser cladding (LC) has gained attention for producing and repairing IN718 components, but their surface integrity and mechanical properties need improvement. A range of experiments were conducted to understand the material removal mechanism of LC fabricated IN718 components in dry milling. Comparative trials with wrought IN718 samples were performed to study the differences. The cutting forces of LC fabricated IN718 samples were larger than that of wrought IN718 samples, and surface plastic deformation and grain refinement were greater. Grain refinement increased microhardness in both types of IN718 components.