The Experts below are selected from a list of 7185 Experts worldwide ranked by ideXlab platform
W J Zong - One of the best experts on this subject based on the ideXlab platform.
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tool Rake Angle selection in micro machining of 45 vol sicp 2024al based on its brittle plastic properties
Journal of Manufacturing Processes, 2019Co-Authors: Sujuan Wang, W J ZongAbstract:Abstract The influence of brittle and plastic properties of 45% volume fraction silicon carbide particle reinforced aluminum matrix composites (45 vol.% SiCp/2024Al) on machining are first taken into account in this work. Considering the coexistence of brittle and plastic properties, a novel micro-machining process is specially proposed for this material to suppress the shedding of SiC particles with a polycrystalline diamond tool, which requires a suitable negative Rake Angle. As expected, the unwanted materials accumulate ahead of tool cutting edge to form the chips and are finally removed under the compressive stress. In this case, the SiC particles are frequently pressed into the machined surface, so the number of shedding particles reduces considerably. As a result, the finished surface roughness is improved, and the tool wear is also suppressed effectively. However, a larger negative Rake Angle induces an excessive cutting force but decreases the stability of machine system, which in return speeds up tool wear and produces a higher surface roughness Sa. Turning experiments show that the smallest surface roughness Sa is achieved when tool Rake Angle is −30°. Moreover, the wear volume of the −30° Rake Angle tool is only 1/22 times the 0° Rake Angle tool.
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Tool Rake Angle selection in micro-machining of 45 vol.%SiCp/2024Al based on its brittle-plastic properties
Journal of Manufacturing Processes, 2018Co-Authors: S.j. Wang, W J ZongAbstract:Abstract The influence of brittle and plastic properties of 45% volume fraction silicon carbide particle reinforced aluminum matrix composites (45 vol.% SiCp/2024Al) on machining are first taken into account in this work. Considering the coexistence of brittle and plastic properties, a novel micro-machining process is specially proposed for this material to suppress the shedding of SiC particles with a polycrystalline diamond tool, which requires a suitable negative Rake Angle. As expected, the unwanted materials accumulate ahead of tool cutting edge to form the chips and are finally removed under the compressive stress. In this case, the SiC particles are frequently pressed into the machined surface, so the number of shedding particles reduces considerably. As a result, the finished surface roughness is improved, and the tool wear is also suppressed effectively. However, a larger negative Rake Angle induces an excessive cutting force but decreases the stability of machine system, which in return speeds up tool wear and produces a higher surface roughness Sa. Turning experiments show that the smallest surface roughness Sa is achieved when tool Rake Angle is −30°. Moreover, the wear volume of the −30° Rake Angle tool is only 1/22 times the 0° Rake Angle tool.
Fengzhou Fang - One of the best experts on this subject based on the ideXlab platform.
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Rake Angle effect in cutting based single atomic layer removal
Journal of Manufacturing Processes, 2020Co-Authors: Fengzhou FangAbstract:Abstract When minimum cutting depth is down to a single atomic layer, two portions of the cutting tool, namely, cutting edge and lowest atoms of the cutting tool, are involved in the cutting-induced material removal. Correspondingly, there are different critical Rake Angles for those two portions of the tool, different from the nominal Rake Angle in conventional cutting and edge radius-induced effective Rake Angle in nanocutting. Both they should be considered in atomic and close-to-atomic cutting to obtain the defect-free processed surface with an ideal crystalline structure. Molecular dynamics modelling is carried out to investigate the critical Rake Angles to enable single atomic layer removal on monocrystalline Cu (1 1 1) surface. The analysis results clearly indicate that the critical Rake Angles of nanometric cutting edge and the lowest tool atoms for single atomic layer removal are among the range of (–70°, –65°) and (–17°, –14°), respectively. To achieve single atomic layer removal, the tool edge radius is suggested to be not greater than 2 nm. The research findings would provide theoretical guidelines to the cutting tool design for the application of mechanical cutting of high-performance atomic scale devices.
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effects of crystallographic orientation and negative Rake Angle on the brittle ductile transition and subsurface deformation in machining of monocrystalline germanium
Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology, 2019Co-Authors: Xiaodong Zhang, Fengzhou Fang, Minghai BiAbstract:Abstract In this study, taper cutting experiments using a diamond tool were conducted to investigate the effects of negative Rake Angle and cutting orientation on the brittle-ductile transition and subsurface deformation of monocrystalline germanium cut on the ( 100 ) , ( 101 ) , and ( 111 ) planes. Confocal laser scanning microscopy and Raman spectroscopy were used to observe the three-dimensional surface topographies of the samples and characterize the subsurface deformation, respectively. The results showed that the negative Rake Angle and crystallographic orientation have a significant effect on the brittle-ductile transition and subsurface deformation mechanisms in ductile regime machining of monocrystalline germanium. A large negative Rake Angle alters the initial surface crack patterns, as well as anisotropic behavior of the ductile-brittle transition and subsurface deformation of monocrystalline germanium.
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study on critical Rake Angle in nanometric cutting
Applied Physics A, 2012Co-Authors: Xiaodong Zhang, Fengzhou FangAbstract:Molecular dynamics (MD) simulations of nanometric-cutting copper are conducted to study the critical Rake Angle during the cutting process. A new approach based on the maximum displacement of atoms in cutting direction is proposed to estimate the chip formation in MD simulation. It is found that the minimum Rake Angle for chip formation is −65∘–(−70∘) and the subsurface deformations of copper are mostly the dislocation and stacking faults. Three-dimensional simulation results show that the effective Rake Angle of stagnation region is constant with the same depth of cut. According to the limited depth of cut of copper can be achieved, the available minimum tool edge radius is suggested to be not less than 10 nm.
Mehdi Heidari - One of the best experts on this subject based on the ideXlab platform.
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effects of tool Rake Angle and tool nose radius on surface quality of ultraprecision diamond turned porous silicon
Journal of Manufacturing Processes, 2019Co-Authors: Mehdi Heidari, Javad AkbariAbstract:Abstract This paper presents an investigation of the effects of tool Rake Angle and nose radius on the surface quality of ultraprecision diamond-turned porous silicon. The results showed that as Rake Angle decreases, the high-stress field induced by the tool edge increases, causing microcracks to propagate extensively near the pore walls. As a result, the ductile-machined areas shrank under a negative tool Rake Angle. On the other hand, brittle fracture occurred around pores released cutting pressure significantly. These trends of Rake Angle effects are distinctly different from those in the cutting of non-porous silicon. Finite element simulation of stress in the cutting area agreed with the experimental results. The results also indicated that using a tool with a bigger nose radius suppressed brittle fractures around the pore edge and improved surface quality. Raman spectroscopy of the ductile-machined surfaces revealed that the amorphization of the subsurface layer became more significant when decreasing tool Rake Angle or increasing tool nose radius. By choosing the optimal tool geometry, a high quality surface can be achieved on porous silicon, which demonstrates the capability of the diamond turning process to fabricate high-precision components.
Sujuan Wang - One of the best experts on this subject based on the ideXlab platform.
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tool Rake Angle selection in micro machining of 45 vol sicp 2024al based on its brittle plastic properties
Journal of Manufacturing Processes, 2019Co-Authors: Sujuan Wang, W J ZongAbstract:Abstract The influence of brittle and plastic properties of 45% volume fraction silicon carbide particle reinforced aluminum matrix composites (45 vol.% SiCp/2024Al) on machining are first taken into account in this work. Considering the coexistence of brittle and plastic properties, a novel micro-machining process is specially proposed for this material to suppress the shedding of SiC particles with a polycrystalline diamond tool, which requires a suitable negative Rake Angle. As expected, the unwanted materials accumulate ahead of tool cutting edge to form the chips and are finally removed under the compressive stress. In this case, the SiC particles are frequently pressed into the machined surface, so the number of shedding particles reduces considerably. As a result, the finished surface roughness is improved, and the tool wear is also suppressed effectively. However, a larger negative Rake Angle induces an excessive cutting force but decreases the stability of machine system, which in return speeds up tool wear and produces a higher surface roughness Sa. Turning experiments show that the smallest surface roughness Sa is achieved when tool Rake Angle is −30°. Moreover, the wear volume of the −30° Rake Angle tool is only 1/22 times the 0° Rake Angle tool.
Javad Akbari - One of the best experts on this subject based on the ideXlab platform.
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effects of tool Rake Angle and tool nose radius on surface quality of ultraprecision diamond turned porous silicon
Journal of Manufacturing Processes, 2019Co-Authors: Mehdi Heidari, Javad AkbariAbstract:Abstract This paper presents an investigation of the effects of tool Rake Angle and nose radius on the surface quality of ultraprecision diamond-turned porous silicon. The results showed that as Rake Angle decreases, the high-stress field induced by the tool edge increases, causing microcracks to propagate extensively near the pore walls. As a result, the ductile-machined areas shrank under a negative tool Rake Angle. On the other hand, brittle fracture occurred around pores released cutting pressure significantly. These trends of Rake Angle effects are distinctly different from those in the cutting of non-porous silicon. Finite element simulation of stress in the cutting area agreed with the experimental results. The results also indicated that using a tool with a bigger nose radius suppressed brittle fractures around the pore edge and improved surface quality. Raman spectroscopy of the ductile-machined surfaces revealed that the amorphization of the subsurface layer became more significant when decreasing tool Rake Angle or increasing tool nose radius. By choosing the optimal tool geometry, a high quality surface can be achieved on porous silicon, which demonstrates the capability of the diamond turning process to fabricate high-precision components.
