scholarly journals Generation Mechanism and Dual Dynamic Simulations of Surface Patterns in Single-Point Diamond Turning of Single-Crystal Copper

2021 ◽  
Author(s):  
Jie Xiong ◽  
Yanbing Chen ◽  
Yuqi Dai ◽  
Guoqing Zhang ◽  
Jiaqi Ran ◽  
...  
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Diamond Turning ◽  
Generation Mechanism ◽  
Machined Surface ◽  
Single Crystal Copper ◽  
Angle Change ◽  
Fundamental Understanding ◽  
Shaped Pattern ◽  
Cutting Direction

Abstract Single-crystal copper (Cu), whose atom arrangement is in the same direction and has no grain boundary, is widely used in defense technology, civil electronics and network communication. As a diamond turnable material, fan-shaped patterns appear on the machined surface, which affects the machined surface quality and the optical function it carries. Previous studies on the surface generation mechanism in single-point diamond turning (SPDT) of Cu were limited to experimental analysis, while there is a lack of fundamental understanding of the fan-shaped pattern generation mechanism and suppression method. In the present study, the different fan-shaped patterns, surface quality, cutting force and chip morphology of the typical crystal planes (100), (110) and (111) planes of Cu were studied by both theoretical and experimental analyses. A molecular dynamics (MD) simulation was conducted to present the fundamental generation mechanism of the fan-shaped patterns from atom arrangement directions and its angle change with the main cutting direction, while a cutting dynamics model was established to simulate the generation of fan-shaped patterns on the machined surface. Based on theoretical and experimental analysis, it was found that the atom density arrangement directions of Cu and its angle change with the main cutting direction of SPDT caused fluctuations in the friction coefficient, which further caused the vibration of the cutting system and generated the fan-shaped patterns. The SPDT of crystal planes (100) can achieve the best surface quality. The present research provides a fundamental understanding of fan-shaped pattern formation on the machined surface, and provides an instruction for machining Cu to obtain better surface quality.

Optical Effects of Surface Finish by Ultraprecision Single Point Diamond Machining

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Lei Li ◽  
Stuart A. Collins ◽  
Allen Y. Yi
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Diamond Turning ◽  
Optical Diffraction ◽  
Machining Process ◽  
Machined Surface ◽  
Tool Marks ◽  
Tool Mark ◽  
Machined Surface Quality ◽  
Machined Surfaces

The single point diamond turning process has been used extensively for direct optical surface fabrication. However, the diamond machined surfaces have characteristic periodic tool marks, which contribute to reduced optical performance such as scattering and distortion. In this paper, studies of the characteristics of diamond machined surface and scattering from the diamond machined surfaces are presented. Four different parameters, the first order optical diffraction, the zero order reflection, the surface roughness, and the residual tool mark depth, are used as indicators for the machined surface quality. Four sets of tests are presented showing the relationship between machined surface quality and machining conditions such as spindle speed, feedrate, and machining process. Finally, an empirical model is given based on the measurements.

scholarly journals Influence of Lubricant Environment on Machined Surface Quality in Single-Point Diamond Turning of Ferrous Metal

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1110
Author(s):  
Menghua Zhou ◽  
Jianpeng Wang ◽  
Guoqing Zhang
Keyword(s):  
Surface Morphology ◽  
Cutting Force ◽  
Surface Quality ◽  
Single Point ◽  
Ferrous Metal ◽  
Minimum Quantity Lubrication ◽  
Diamond Turning ◽  
Machined Surface ◽  
Hard Particles ◽  
Machined Surface Quality

In the field of single-point diamond turning (SPDT), machining ferrous metal is an important research topic with promising application. For SPDT of ferrous metal, the influence of lubricant on the workpiece surface morphology remains to be studied. In this study, three lubricant machining environments were selected to carry out specific control experiments. The machined surface morphology and cutting force in different lubricant machining environments were analyzed. The experiment results showed that the lubricant environment will have significant impacts on the quality of the machined surface morphology of ferrous metal. In the environment of minimum quantity lubrication machining (MQLM-oil), better machined surface quality can be obtained than that in ordinary dry machining (ODM) and high-pressure gas machining (HGM). Furthermore, the cutting force captured in the ODM and HGM environment increased with the increase of the cutting depth, while the cutting force in the MQLM-oil environment remained almost unchanged. That indicates MQLM-oil can suppress the formation of hard particles to improve the machining quality.

Machining Induced Defects and the Influence Factors when Diamond Turning of SiCp/Al Composites

2007 ◽  
Vol 10-12 ◽  
pp. 626-630 ◽  
Author(s):  
Y.F. Ge ◽  
Jiu Hua Xu ◽  
Hui Yang ◽  
S.B. Luo ◽  
Yu Can Fu
Keyword(s):  
Surface Quality ◽  
Volume Fraction ◽  
Single Point ◽  
Influence Factors ◽  
Polycrystalline Diamond ◽  
High Volume ◽  
Diamond Turning ◽  
Dry Cutting ◽  
Machined Surface ◽  
Pcd Tools

Ultra-precision turning tests on SiCp/2024Al and SiCp/ZL101A composites were carried out to investigate the surface quality using single point diamond tools (SPDT) and polycrystalline diamond (PCD) cutters. Examined by SEM, the machined surfaces took on many defects such as pits, voids, microcracks, grooves, protuberances, matrix tearing and so on. The results showed that surface quality debased with increasing feed rate or using of high volume fraction materials. Dry cutting would deteriorate the surface finish. It was also pointed out that SPDT outperformed PCD tools although they produced the same surface roughness Ra. Microhardness measuring showed that the deformation layer was extended to 8–16μm below the machined surface.

A Study of Cutting Strategy in Single-Point Diamond Turning of Micro V-Groove Patterns on Precision Roller Drums

2014 ◽  
Vol 625 ◽  
pp. 742-747
Author(s):  
C.H. Mak ◽  
C.F. Cheung ◽  
M.J. Ren ◽  
L.B. Kong ◽  
S. To
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Cutting Parameters ◽  
Diamond Turning ◽  
Surface Generation ◽  
Depth Of Cut ◽  
Tool Paths ◽  
Cutting Strategy ◽  
Groove Pattern

This paper presents a study of cutting strategies on the surface generation in single-point diamond turning of micro V-groove patterns on precision roller drums. An aluminium precision roller drum with a diameter 250mm and 100 long was diamond turned with a V-groove pattern. A series of cutting experiments were designed to study the effect of the variation of various cutting parameters and cutting tool paths on the surface quality in diamond turning of the precision roller drum. The parameters under investigation included the depth of cut, number of steps and the depth for each cut when diamond turning V-grooves on the cylindrical surface of a workpiece. The measurement result indicates that the surface quality of V-grooves machined on the precision roller drums is affected by cutting strategies. The optimal cutting strategy for machining a V-groove pattern on a precision drum with 5µm depth was obtained.

scholarly journals Ultra-Precision Single-Point Diamond Turning of a Complex Sinusoidal Mesh Surface Using Machining Accuracy Active Control

2021 ◽  
Vol 67 (7-8) ◽  
pp. 343-351
Author(s):  
Peixing Ning ◽  
Ji Zhao ◽  
Shijun Ji ◽  
Jingjin Li ◽  
Handa Dai
Keyword(s):  
Active Control ◽  
Tool Path ◽  
Single Point ◽  
Diamond Turning ◽  
Machining Accuracy ◽  
Machining Error ◽  
Machined Surface ◽  
Mesh Surface ◽  
Slow Tool Servo ◽  
Radius Compensation

Single-point diamond turning (SPDT) assisted with slow tool servo (STS) is the most commonly utilized technique in the fabrication of optical modules. However, the tool path significantly affects the quality of the machined surface. In order to realize the determined machining accuracy effectively, a tool path generation (TPG) method based on machining accuracy active control (MAAC) is presented. The relationship between tool path and machining error is studied. Corner radius compensation (CRC) and the calculation of chord error and residual error are detailed. Finally, the effectiveness of the proposed approach is verified through a machining error simulation and a cutting experiment of a complex sinusoidal mesh surface fabrication.

scholarly journals Ductile behavior of optical glass in single point diamond turning

2014 ◽  
Vol 67 (2) ◽  
pp. 167-172
Author(s):  
Carlos Renato Pagotto ◽  
Jaime Gilberto Duduch ◽  
Renato Goulart Jasinevicius
Keyword(s):  
Optical Glass ◽  
Elastic Recovery ◽  
Single Point ◽  
Tool Material ◽  
Diamond Turning ◽  
Machined Surface ◽  
Force Microscopy ◽  
Semiconductor Crystals ◽  
Ductile Machining ◽  
Ductile Behavior

Single point diamond turning tests were carried out on a B270 type glass. Submicrometer cutting conditions were applied in order to generate ductile response during single point machining. The profile generated by the rapid removal of the tool tip from the machined surface, analyzed by atomic force microscopy, showed that the brittle-to-ductile transition occurs at a few tenths of micrometers. According to the machining results, the maximum feed rate capable of generating a ductile mode machining behavior is of 0.9 micrometer/revolution. Furthermore, it was shown that with the cutting depth lower than 0.100 micrometer/revolution, the material removal mechanism is totally ductile. Ribbon-like chips were not observed when ductile machining was performed, as commonly seen during ductile machining of semiconductor crystals. The chips removed had a small needle-like shape. This material's fragile behavior during machining may be related to high densification during tool/material interaction with subsequent elastic recovery response.

Freeform machining of ophthalmic toric lens mould using fast tool servo-assisted ultra-precision diamond turning process

2020 ◽  
pp. 251659842093974
Author(s):  
Ishan Anand Singh ◽  
Gopi Krishna S. ◽  
T. Narendra Reddy ◽  
Prakash Vinod
Keyword(s):  
Surface Roughness ◽  
Single Point ◽  
Measurement Data ◽  
Surface Profile ◽  
Diamond Turning ◽  
Fast Tool Servo ◽  
Toric Surface ◽  
Machined Surface ◽  
Ultra Precision ◽  
A Minor

This research aims to establish a methodology for machining of toric lenses, using fast tool servo-assisted single point diamond turning and to assess the generated surface for its characteristics. Using the established mathematical model, toric surface is explained to understand the geometry and to generate the parameters required for fast tool servo machining. A toric surface with a major diameter of 18.93 mm and a minor diameter of 15.12 mm has been cut on the intelligent ultra-precision turning machine (iUPTM). The surface profile and surface roughness were measured. After analysing the measurement data of the machined surface, on two perpendicular axes of the toric lens, form accuracy of 0.49 µm peak-to-valley (PV), and surface roughness of 12 nm in Ra, 4–8 nm in Sa are obtained. From the experimental results obtained, it can be concluded that the proposed method is a reasonable alternative for manufacturing toric lens mould.

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