Effect of diamond tool sharpness on minimum cutting thickness and cutting surface integrity in ultraprecision machining

1996 ◽  
Vol 62 (4) ◽  
pp. 327-330 ◽  
Author(s):  
Z.J. Yuan ◽  
M. Zhou ◽  
S. Dong
Keyword(s):  
Surface Integrity ◽  
Diamond Tool ◽  
Ultraprecision Machining ◽  
Cutting Surface

On-Machine Diamond Tool Shaping to Realize Highly Efficient Ultraprecision Machining System

2020 ◽  
Author(s):  
Meng Xu ◽  
Naoyo Yokoyama ◽  
Keiichi Nakamoto ◽  
Yoshimi Takeuchi
Keyword(s):  
Diamond Tool ◽  
Machining Accuracy ◽  
Ultraprecision Machining ◽  
Center Point ◽  
Critical Issues ◽  
Machining System ◽  
Tool Setting ◽  
Ideal Tool ◽  
Flank Face ◽  
Point Detection

Abstract Tool wear is one of the critical issues which deteriorate machining accuracy in ultraprecision machining. However, tool setting errors caused by the change of worn tool during a machining operation should be carefully compensated by identifying the gaps between the ideal tool center point and the actual tool center point, which inevitably lead to low machining efficiency. Because of the long consumption time of actual tool center point detection, this study aims at achieving on-machine shaping of a diamond tool which is commonly used in ultraprecision machining. In the previous study, shaping conditions without tool chipping are investigated by using various shaping materials. Then, in order to create a flank face that is necessary to realize preferable cutting, a pin gauge made of cemented carbide is adopted as the shaper. From the conducted experiments, it is found that the proposed on-machine shaping can create a specific cutting edge and a flank face on an ultraprecision machine tool.

Surface integrity under diamond tool wear effects in ultra-precision raster milling of a Zn–Al–Cu alloy

2018 ◽  
Vol 233 (4) ◽  
pp. 1111-1118 ◽  
Author(s):  
Zengwen Dong ◽  
Shaojian Zhang ◽  
Zhiwen Xiong
Keyword(s):  
Tool Wear ◽  
Surface Integrity ◽  
High Speed ◽  
Diamond Tool ◽  
Flank Wear ◽  
Orthogonal Cutting ◽  
Phase Changes ◽  
Crater Wear ◽  
Cu Alloy ◽  
Ultra Precision

In ultra-precision raster milling, the material removal process determines surface integrity. In this study, surface integrity was discussed under diamond tool wear effects in ultra-precision raster milling of a Zn–Al–Cu alloy. The results firstly showed that under high speed cutting in ultra-precision raster milling, quenching took place with phase decomposition (namely twin phase changes) with a deformation thickness of even less than 100 nm. Flank wear enhanced phase changes, promoted surface hardening, degraded surface quality, and increased deformation thickness, but crater wear gave better surface integrity. The intrinsic reason is that flank wear caused more external stress but crater wear was reverse, well supported by finite element simulation in orthogonal cutting. Significantly, it provides a further insight into diamond tool wear effects on surface integrity in ultra-precision raster milling of a Zn–Al–Cu alloy.

Molecular Dynamics Simulation of Plastic Deformation of Diamond at an Elevated Temperature

2014 ◽  
Vol 626 ◽  
pp. 329-333
Author(s):  
K.Y. Fung ◽  
C.Y. Tang ◽  
Chi Fai Cheung ◽  
Wing Cheung Law
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Temperature Gradient ◽  
Diamond Tool ◽  
Dynamics Simulation ◽  
Maximum Temperature ◽  
Material Damage ◽  
Ultraprecision Machining ◽  
Secondary Cracks ◽  
Single Crystal Diamond

Single point diamond tools are commonly used for ultraprecision machining. At high cutting speeds, frictional contact and local heat may cause material damage to the diamond tool. The diamond crystal is softened and its mechanical strength decreases with the increase in temperature. Plastic deformation of diamonds was recently reported in some experimental studies. In this work, a molecular dynamics (MD) simulation was implemented to predict the deformation of single crystal diamond at various temperatures. Diamond is brittle at room temperature, however, it starts to exhibit plastic dislocation at a temperature above 1200 K under a confining pressure. The condition in ultraprecision machining is indeed a temperature gradient distribution at the tool tip, between the maximum temperature at the tool-workpiece interface and the average temperature at the core. The simulation results predicted that diamond deformed plastically under the gradient between 1500K and 860K. It is surprising that secondary cracks were resulted from the gradient, as comparing to a single slip obtained in an evenly distributed temperature. Bond dissociation nucleated the fractures along the (111) shuffle planes, perfect dislocation merely occurred in the hot zone and sp3-to-sp2 disorder at the cool zone. The temperature gradient created a lattice mismatch and nucleated the secondary cracks. The results give an insight that a catastrophic fracture and local material damage can occur at a diamond tool tip at the cutting temperature above 1200 K, due to softening and graphitization.

The Cutting Residual Stress Included in the Surface Integrity

2014 ◽  
Vol 893 ◽  
pp. 638-643
Author(s):  
Juan Huang ◽  
Gui Cheng Wang
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Surface Integrity ◽  
Cutting Parameters ◽  
Residual Stress Distribution ◽  
Distribution Law ◽  
Surface Residual Stress ◽  
Machined Surface ◽  
Cutting Surface ◽  
Experimental Researches

This article is for the integrity of the cutting surface, explaining the reason for the cutting residual stress generated from the mechanism, proposed several typical methods to reduce the residual stress. According to some experimental researches on cutting parameters which have been done by previous scholars, this article gives some analysis of the effects of cutting parameters of residual stress. And preliminary summary of the influence of residual stress on cutting parameters, it also provides a way for further discussion of cutting parameters and material effect on the machined surface residual stress distribution law.

The use of high-resolution methods of research in the design of the diamond-matrix interface to increase the durability of the diamond tool

2020 ◽  
Vol 86 (6) ◽  
pp. 62-71
Author(s):  
P. P. Sharin ◽  
S. P. Yakovleva ◽  
M. P. Akimova ◽  
V. I. Popov
Keyword(s):  
High Resolution ◽  
Diamond Tool ◽  
Diamond Surface ◽  
Matrix Interface ◽  
Reaction Products ◽  
Diamond Tools ◽  
Functional Composites ◽  
Mechanical Adhesion ◽  
Carbide Matrix ◽  
Diamond Retention

The results of studying fundamental and applied problems regarding the formation of boundary layers between diamond and carbide matrix are presented with the goal to develop a highly resistant diamond tool. The new approaches to the synthesis of diamond-carbide materials combining diamond metallization and sintering in a single-stage technology are presented. The developed technology eliminates the re-heating of a metallized coatings which results in their destruction and enhanced graphitization of diamond (these phenomena restrict using metallization procedure to improve diamond retention and synthesis of high-functional composites for diamond tools). The goal of the study is analysis the structural and phase state of the «diamond – carbide matrix» interface in a diamond tool obtained by the new technology and the main factors determining the level of diamond retention in the presence of a metallized coating. Unique opportunities provided by modern high-resolution methods of research were used in the study. The elemental composition and morphological features of the diamond-matrix interface were studied using the methods of scanning electron microscopy, atomic force microscopy, X-ray microanalysis and Raman spectroscopy. Identification of the reaction products, including non-diamond carbon was performed. It is shown that the introduction of the powder-metallizer significantly modified the contact boundaries and provide conditions for improving the chemical and mechanical adhesion of the diamond-matrix system. The formation of the well-developed nano- and sub-microscale roughness of the diamond surface and dense filling of the existing voids with nanoscale layers of metal-infiltrate was revealed. The multilevel organization of highly structured elements of the transition zone with the minimal graphitization ensured the monolithic character and strength of the diamond-matrix bond. Comparative service tests of preproduction and control samples of diamond dressers proved the efficiency of developed hybrid technology (the specific performance of diamond tools increased by 39 – 45%). New fundamental and applied results have been obtained in the field of studying interface zones in crystalline multiphase systems that can be used to regulate adhesion phenomena at the interphase boundaries and develop highly efficient composite materials.

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