Atomic simulation for the effect of nano-cutting parameters on the 3D surface morphology of polycrystalline γ-TiAl alloy

The effects of sample structure and tool geometry are studied under cutting simulation to verify the deformation, removal mechanisms, and subsurface defection of lamellar twined CoCuFeNiPd alloys. These findings suggest that the twin boundary spacing and twin inclination angle (β) are the main determinants of surface wear characteristics and cutting-induced surface harm. The maximum cutting force achieved with TBS = 8a and β =900. The high friction coefficient with the sample has TBS = 8a and β = 900, showing that the tool's moving in the substrate is strongly restricted. Furthermore, the surface topography is not sensitive to the TBS and β. The best-machined surface is achieved with TBS = 3a and 4a under twin inclinations of 0 and 300. The effect of edge radius (R), rake angle (γ), and clearance angle (α) on the deformation behavior is examined. The negative of γ, small α, or larger R results in a higher cutting force, a worse subsurface, and a lower cutting pile-up height. With a positive γ, a large α or small R has a larger average friction coefficient, which implies a higher resistance rate. The tool with a smaller R or positive γ can improve the machined surface's smoothness.

Section: The Cutting Processmentioning

confidence: 93%

Material deformation mechanism of lamellar twined high–entropy alloys during machining

Vu,

Pham,

Fang

2024

“…By studying chip, hydrostatic stress distribution and dislocation density, the mechanism of influence of different cutting speeds and cutting depths on surface quality and subsurface damage was described. Guo et al [17] investigated the influence of cutting depths and cutting speeds on the machined surface topography during nano-cutting of polycrystalline γ-TiAl alloys by MD. The results show that a smaller cutting depth and an appropriately higher cutting speed can effectively improve the surface quality of the polycrystalline γ-TiAl alloy, and optimize its nano-cutting process.…”

Section: Introductionmentioning

confidence: 99%

Effect of repetitive nano-cutting tool parameters on surface quality and subsurface damage of γ-TiAl alloy

Liu,

et al. 2024

Self Cite

In this paper, the molecular dynamics simulation of the repeated nanocutting of single crystal γ-Tial alloy was carried out by selecting different geometric parameters of the second cutting tool by single factor experiment. The cutting force, friction coefficient, subsurface defects, dislocation evolution and surface roughness of the second cutting were analyzed systematically. The results show that when the tool rake angle is 15°, the surface roughness is lower and the surface quality is better. The influence of different second cutting tool rake angle on the surface roughness is not strong. When the rake angle of the second cutting tool and the radius of edge are constant, the average normal cutting force decreases with the increase of the clearance angle of the tool. Under the machining parameters in this paper, the critical clearance angle of the second cutting of single crystal γ-TiAl alloy is between 10° and 15°. When the tool clearance angle is greater than the critical clearance angle, the average cutting force and the machined-surface roughness no longer change significantly. With the increase of the radius of the second cutting tool, the chip decreases, the subsurface defect increases, and the surface roughness of the machined surface also increases with strong regularity.

“…In recent years, domestic and foreign scholars have carried out a large number of experimental studies and simulations on single and polycrystalline metal material cutting, including the study of cutting process parameters [11][12][13], tool geometry parameters [14,15], cutting temperature [16], grain boundaries [17], grain size [18][19][20] and so on. Guo et al used MD simulation to study the effect of process parameters on the cutting process of polycrystalline γ-TiAl alloy workpieces, and concluded that the average cutting force and friction coefficient increase with the increase of the depth of cut; increasing the cutting speed will induce amorphization of the material and plastic side flow, leading to a significant increase in the contour peaks on both sides of the machined surface [21]. Geng et al used MD simulation to study the effect of cutting force on atomic flow and material buildup [22].…”

Section: Introductionmentioning

confidence: 99%

Molecular dynamics simulation of the effect of tool parameters on nano-cutting of polycrystalline γ-TiAl alloys

Zhou,

Cao,

Zhou

et al. 2024

Self Cite

As one of the most promising lightweight high -temperature structural materials in the future, the surface quality of γ-TiAl alloys has a great influence on the performance of the workpieces, and the tool parameters are an important factor affecting the machining results. In this study, molecular dynamics (MD) simulations of the nano -cutting process of polycrystalline γ TiAl alloys with different tool parameters were carried out.- The results show that increasing the tool rake angle and decreasing the tool edge radius within a certain range helps to reduce the average cutting force , cutting force fluctuation, cutting temperature, and stabilize the cutting process, while the change of the tool clearance angle has less influence on the cutting process. in contrast, negative rake angle cutting is more likely to produce grain rotation and grain boundary steps in the processed substrate and increase the processed surface roughness than positive rake angle cutting; increasing the tool rake angle within a certain range will weaken the elastic recovery effect of the substrate . During cutting at a positive rake angle, whether a portion of the substrate is prone to slip toward the surface of the substrate, thereby reducing the surface quality, depends on the relative state of grain orientation and force applied in the substrate.