A study of the cutting performance of poly-crystalline oxygen free copper with single crystalline diamond micro-tools

Zhang

2017

Nanoscale Res Lett

The side flow of material in nano cutting is one of the most important factors that deteriorate the machined surface quality. The effects of the crystallographic orientation, feed, and the cutting tool geometry, including tool edge radius, rake angle and inclination angle, on the side flow are investigated employing molecular dynamics simulation. The results show that the stagnation region is formed in front of tool edge and it is characterized by the stagnation radius R s and stagnation height h s. The side flow is formed because the material at or under the stagnation region is extruded by the tool edge to flow to the side of the tool edge. Higher stagnation height would increase the size of the side flow. The anisotropic nature of the material which partly determines the stagnation region also influences the side flow due to the different deformation mechanism under the action of the tool edge. At different cutting directions, the size of the side flow has a great difference which would finally affect the machined surface quality. The cutting directions of {100} < 011>, {110} < 001>, and {110} < 1-10 > are beneficial to obtain a better surface quality with small side flow. Besides that, the side flow could be suppressed by reducing the feed and optimizing the cutting tool geometry. Cutting tool with small edge radius, large positive rake angle, and inclination angle would decrease the side flow and consequently improve the machined surface quality.

Section: Introductionmentioning

confidence: 99%

Side Flow Effect on Surface Generation in Nano Cutting

Zhang

2017

Nanoscale Res Lett

“…And the processing forces would be influenced by the size effect and anisotropy of materials. Therefore, when decreasing the UCT, the effect of cutting direction which is actually the effect of crystallographic orientation or anisotropy of the materials on the cutting process becomes non-ignorable, whether the workpiece is single or polycrystalline material [138,181,193]. In 1994, Yuan et al [181] experimentally investigated the influence of crystallographic orientations on the cutting force and generated surface roughness.…”

Section: Influence Of Ductile Materialsmentioning

confidence: 99%

Recent Advances in Micro/Nano-cutting: Effect of Tool Edge and Material Properties

2018

Nanomanuf Metrol

Micro-and nano-machining technology has been applied in industry to generate high-precision parts with micro/nanometric accuracy or feature size in the recent decades. Cutting is one of the most powerful manufacturing processes, and the material removal mechanism is urgently demanded by the industry to understand and improve the micro/nano-machining process efficiently at a low cost. This paper presents the recent advances in cutting mechanism and its applicability for predicting the surface generation and chip formation, especially when material is removed in micro-and nanoscale. In addition to the industry-concerned performance parameters, fundamental physical parameters such as stresses, strains, temperatures, phase transformation, minimum uncut chip thickness and size effects are discussed in this paper for the indepth understanding of the micro/nano-cutting process.

“…It is smaller than the material grain size causing the significant appearance of the size effects of materials [8]. The anisotropic nature of single crystal materials would exhibit in the cutting processes, even the machined materials are polycrystalline, such as the variation of surface roughness obtained at different crystallographic orientation of grains in copper [9]. To better understand the influence of anisotropy on surface generation of single crystal materials, much attention has been attracted.…”

Section: Introductionmentioning

confidence: 99%

Study on Crystallographic Orientation Effect on Surface Generation of Aluminum in Nano-cutting

Zhu

et al. 2017

Nanoscale Res Lett

The material characteristics such as size effect are one of the most important factors that could not be neglected in cutting the material at nanoscale. The effects of anisotropic nature of single crystal materials in nano-cutting are investigated employing the molecular dynamics simulation. Results show that the size effect of the plastic deformation is based on different plastic carriers, such as the twin, stacking faults, and dislocations. The minimum uncut chip thickness is dependent on cutting direction, where even a negative value is obtained when the cutting direction is {110}<001>. It also determines the material deformation and removal mechanism (e.g., shearing, extruding, and rubbing mechanism) with a decrease in uncut chip thickness. When material is deformed by shearing, the primary shearing zone expands from the stagnation point or the tip of stagnation zone. When a material is deformed by extruding and rubbing, the primary deformation zone almost parallels to the cutting direction and expands from the bottom of the cutting edge merging with the tertiary deformation zone. The generated surface quality relates to the crystallographic orientation and the minimum uncut chip thickness. The cutting directions of {110}<001>, {110}<1-10>, and {111}<1-10>, whose minimum uncut chip thickness is relatively small, have better surface qualities compared to the other cutting direction.