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Laser-assisted diamond cutting is a promising method for the cost-effective machining of hard and brittle materials. A deep knowledge of the material removal mechanism and the attainable surface integrity is crucial to the development of this new technique. This paper focuses on the application of laser-assisted diamond cutting to single-crystal silicon to investigate key characteristics of the process. These characteristics are the critical depth of cut for ductile–brittle transition, machined surface roughness, resultant micro-cutting force, friction coefficient, temperature distribution, microstructure change, and the subsurface damage of the machined silicon. Laser-assisted diamond cutting method is compared with the conventional single-point diamond cutting method. The experimental results reveal that laser-assisted diamond cutting can enhance the silicon’s ductility and machinability by decreasing the softened material’s hardness and promoting the atomic activity in the subsurface layer. The critical depth of cut has been increased by up to 364% with laser assistance, and its degree generally increases with the increase of temperature. The friction coefficient has been decreased by up to 27.95%. The cross-sectional transmission electron microscope observation results indicate that laser-assisted diamond cutting is able to effectively inhibit the formation of the distorted layer and produce less subsurface damage of single-crystal silicon. In comparison to the conventional single-point diamond turning of single-crystal silicon, a significant improvement of surface quality has been obtained by laser-assisted diamond cutting: Sz has been reduced by 87%, and Sa has been reduced by 50%.

Achieving nanometric surface on single-crystal silicon is important for semiconductor and optoelectronics industries. In recent years, thermal assisted machining (hot machining) raises as an effective technique for high-quality surface fabrication of single-crystal silicon. However, the formation mechanism of the subsurface damage at elevated cutting temperatures is still unclear. In this paper, molecular dynamics simulation and cutting experiments were conducted to study the subsurface damage evolution in single-crystal silicon at elevated cutting temperatures. The cutting mechanism and behavior of the amorphous phase were investigated. The results indicate that with an increase of the cutting temperature, the subsurface damage can be greatly suppressed and the cutting mechanism can be distinct with ordinary cutting. Furthermore, the lubricant effect of the amorphous layer and the recrystallization process are determined as two important reasons for suppression of the subsurface damage at high cutting temperature. The lubricant effect reduces the deformation of the crystal substrate and decreases the frictional coefficient during cutting. While the recrystallization mainly occurs before the compressive stress decrease to zero, which causes point-like subsurface damage and thinner amorphous layer on the machined surface.

Silicon carbide (SiC) is an important material in many industrial applications. However, due to the hardness and brittleness nature, achieving ultra-precision machining of SiC is still challenging. In recent years, function surface with micro-structures has been introduced in cutting tool to suppress wear process. But the wear mechanism of the structured tool has not been revealed completely. Therefore, in present research, molecular dynamic simulations were conducted to investigate the cutting performance of the micro-structure on the nano scale cutting process of 3C-SiC. The simulation results showed that the dislocation propagation in workpiece can be suppressed with a structured tool. The micro-structures have a significant influence on the stress distribution in the workpiece subsurface. Furthermore, the abrasive wear of the structured tool is obvious smaller since the edges of the tool became blunt and the contact face between tool and workpiece changed to the close-packed plane of diamond. Moreover, the amorphization of the structured tool is effectively suppressed. This study contributes to the understanding of the material behavior involved in the ultra-precision cutting of SiC.

Laser-assisted diamond cutting is a promising process for machining hard and brittle materials. A deep knowledge of material removal mechanism and attainable surface integrity are crucial to the development of this new technique. This paper focuses on the application of laser-assisted diamond cutting to single crystal silicon to investigate key characteristics of this process. The influence of laser power on the ductile machinability of single crystal silicon, in terms of the critical depth of cut for ductile-brittle transition in laser-assisted diamond cutting, is investigated quantitatively using a plunge-cut method. The experimental results reveal that this process can enhance the silicon’s ductility and machinability. The critical depth of cut has been increased by up to 330% with laser assistance, and its degree generally increases with the increase of laser power. The cross-sectional transmission electron microscope observation results indicate that laser-assisted diamond cutting is able to realize the subsurface damage free processing of single crystal silicon. In order to verify the ability of the laser-assisted diamond cutting to improve the surface quality, the face turning tests are also carried out. A significant improvement of surface quality has been obtained by laser-assisted diamond cutting: Sz (maximum height) has been reduced by 85% and Sa (arithmetical mean height) has been reduced by 45%.