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This study delves into the grinding-induced microstructural and mechanical evolution in high-entropy nickel-based superalloys GH4169 and DD5, underscoring their distinct behaviors under varying machining conditions. Leveraging "Random Substitution" in Material Studio, the research developed intricate atomic models to accurately depict the complex chemical compositions and microstructures of these superalloys. Neper software was employed for multi-scale modeling, specifically analyzing the unit cells of GH4169. A critical focus was placed on the effects of key grinding parameters—depth, spindle speed, and feed rate—on the crystallographic deformation of GH4169, contrasting it with the response of DD5. The study highlighted a notable transition in GH4169's material removal mechanism from plastic flow to chip spallation at enhanced grinding depths and feed rates, while maintaining lattice integrity at higher grinding speeds. GH4169 consistently demonstrated greater tangential and normal forces during grinding compared to DD5, reflecting intricate machining complexities. The differential crystal orientations between these superalloys significantly impacted the grinding force distribution and heat dissipation during the process. This comprehensive analysis provides pivotal insights into the micro-level grinding process parameters, enriching both theoretical and practical understanding of material machinability in advanced manufacturing contexts. The study's novelty lies in its application of detailed atomic models and multi-scale modeling to uncover subtle microstructural and mechanical dynamics during the grinding of superalloys. [ABSTRACT FROM AUTHOR]

Nickel-based single crystal superalloys exhibit excellent mechanical properties that make them suitable for aviation and industrial steam turbine blades. However, due to their distinguished properties, processing such materials becomes challenging. In order to enhance the fatigue life of workpiece processing, this research involved the development of a three-dimensional Hill simulation model of a single abrasive grain based on the anisotropic parameters of materials. The study also explored the formation mechanisms of the subsurface metamorphic layer of nickel-based single crystal superalloy DD5. The influence of grinding process parameters, such as wheel speed (vs), grinding depth (ap), and feed rate (vf), on the subsurface metamorphic layer of the workpiece was comparatively analyzed. In addition, the influence of the grinding process parameters on the thickness of the metamorphic layer of the (001) crystal plane of the workpiece was examined. The low damage grinding parameters of DD5 were determined to be as follows: the linear speed of the wheel speed is 35 m/s, the grinding depth is 20 μm, and the feed rate is 0.2 m/min. Further, combining with experimental analysis, the influence of each grinding process parameter was analyzed, whereby the wheel speed was found to have the greatest influence on the metamorphic layer of the workpiece. [ABSTRACT FROM AUTHOR]

Single-crystal materials have emerged as a new class of materials widely utilized in the aerospace field. This paper aims to study nickel-based single crystal superalloy DD5, a notoriously challenging material to process. Among the various machining techniques, grinding can achieve superior surface quality with minimal size errors, making it an ideal choice for this experiment. Consequently, this research utilizes the grinding method to investigate the subsurface deformation mechanism of nickel-based single crystal superalloy. To investigate the subsurface plastic damage layer in nickel-based single crystal superalloy, the Hollomon relationship is employed to elaborate on the subsurface plastic deformation mechanism. Furthermore, an effective removal thickness model of a single abrasive grain was established in this study to examine the impact of grinding on the subsurface of nickel-based single crystal superalloy DD5. The model analyzes the influencing factors of subsurface plastic deformation in the grinding process, evaluates the different grinding parameters' effects on the maximum plastic deformation of subsurface and plastic deformation thickness, and compares the simulation with experimental results. The findings indicate that the subsurface damage of the workpiece is primarily affected by the maximum plastic deformation rate, and the plastic deformation in the workpiece is typically influenced by material properties. Within the experimental parameters, the plastic deformation of nickel-based single crystal superalloy reduces with an increase in wheel speed while subsurface plastic deformation increases with a rise in feed rate and grinding depth. Among other processing parameters, the wheel speed has the most significant effect on subsurface plastic deformation during the grinding process. [ABSTRACT FROM AUTHOR]